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Mwo Gettingstarted

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . .MWO/VSS 2002

Getting StartedGuide

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MWO/VSS Getting Started GuideV5.5, May 2002

Applied Wave Research, Inc.1960 E. Grand Avenue, Suite 430El Segundo, CA 90245

Voice 310.726.3000Fax 310.726.3005Technical Support [email protected] Website www.mwoffice.com

© 2002 Applied Wave Research, Inc. All Rights Reserved. Printed in the United States of America. No part of this guide may be reproduced in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the express written permission of Applied Wave Research, Inc.AWR�, Microwave Office�, Visual System Simulator�, and EMSight� are trademarks of Applied Wave Research, Inc. All other product and company names mentioned herein may be the trademarks or registered trademarks of their respective owners.The information in this guide is believed to be accurate. However, no responsibility or liability is assumed by Applied Wave Research, Inc. for its use.

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CONTENTS

1 INTRODUCING AWR DESIGN ENVIRONMENT ................... 1-1About This Guide .........................................................................1-2Getting Additional Information .................................................1-3

2 INSTALLING MWO/VSS .................................................... 2-1Installation Overview ...................................................................2-1

Licensing and Available Features .......................................2-1Installing Downloaded Versions ........................................2-1In Case of Installation Errors.............................................2-2

Preparing for Installation .............................................................2-2Installation Procedure ..................................................................2-3Installing the Vendor Libraries....................................................2-5Obtaining Your FLEXlm License ..............................................2-5

3 AWR DESIGN ENVIRONMENT .......................................... 3-1Starting AWR Programs...............................................................3-1AWR Environment Components ...............................................3-2Basic Operations ...........................................................................3-4

Working With Projects ........................................................3-4Working With Schematics and Netlists in MWO............3-5Working with System Diagrams.........................................3-6The Element Browser..........................................................3-7Creating a Layout with MWO ..........................................3-11Creating Output Graphs and Measurements .................3-14Performing Simulations.....................................................3-15Adding Subcircuits to System Diagrams ........................3-17Scripts and Wizards............................................................3-17

Using Online Help ......................................................................3-18

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C O N T E N T S

4 USING THE LINEAR SIMULATOR ..................................... 4-1Linear Simulations in Microwave Office ...................................4-1How to Create a Lumped Element Filter..................................4-1

5 CREATING LAYOUTS FROM SCHEMATICS ...................... 5-1Layouts in Microwave Office ......................................................5-1

Layout Tips and Tricks ........................................................5-1Creating a Layout From a Schematic .........................................5-2

6 USING THE NONLINEAR SIMULATOR .............................. 6-1Harmonic Balance in Microwave Office ...................................6-1

Single-Tone Analysis ............................................................6-1Multi-Tone Analysis .............................................................6-2Nonlinear Measurements ....................................................6-2

How to Create a Power Amplifier Circuit .................................6-2

7 USING THE ELECTROMAGNETIC SIMULATOR ................. 7-1EM Simulation in Microwave Office .........................................7-1Creating a Distributed Interdigital Filter ...................................7-2

8 CREATING A VSS SIMULATION ....................................... 8-1Creating a Project ..........................................................................8-1

Setting Default System Settings..........................................8-2Creating a System Diagram.................................................8-3Placing Blocks in a System Diagram .................................8-4Specifying System Simulator Options ...............................8-8Creating a Graph to View Results .....................................8-9Adding a Measurement......................................................8-10Running the Simulation and Analyzing Results .............8-11

Tuning a System Parameter .......................................................8-14Creating a BER Simulation........................................................8-15

9 ADDING AN MWO SUBCIRCUIT TO A SYSTEM ................. 9-1Creating a Schematic and Adding an Ideal MWO Filter 9-1

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C O N T E N T S

Verifying Filter Performance ..............................................9-5Experimenting with Filters .................................................9-6

10 USING AN MWO NONLINEAR ELEMENT IN VSS ........... 10-1Importing an Amplifier Model into VSS.................................10-1

Compensating for Phase Shift ..........................................10-4Tuning the Simulation........................................................10-5Using the Vector Signal Analyzer Block .........................10-5

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C O N T E N T S

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .INTRODUCING AWR DESIGN ENVIRONMENT 1

Welcome to the AWR Design Environment!

The AWR Design Environment comprises two powerful tools that can be used together to create an integrated system and RF design environment: Visual System Simulator� (VSS) and Microwave Office (MWO). These powerful tools are fully integrated in the AWR Design Environment and allow you to incorporate circuit designs into system designs without having to leave the AWR Design Environment.

Microwave Office enables you to design circuits composed of schematics and electromagnetic (EM) structures from an extensive electrical model database, and then generate layout representations of these designs. You can perform simulations using one of Microwave Office�s simulation engines -- a linear simulator, an advanced harmonic balance or Volterra-series nonlinear simulator, or a 3D-planar EM simulator (EMSight�) -- and display the output in a wide variety of graphical forms based on your analysis needs. You can then tune or optimize the designs and your changes are automatically and immediately reflected in the layout.

VSS enables you to design and analyze end-to-end communication systems. You can design systems composed of modulated signals, encoding schemes, channel blocks and system level performance measurements. You can perform simulations using VSS�s predefined transmitters and receivers, or you can build customized transmitters and receivers from basic blocks. Based on your analysis needs, you can display BER curves, ACPR measurements, constellations, and power spectrums, to name a few. VSS provides a real-time tuner that allows you to tune the designs and then see your changes immediately in the data display.

OBJECT ORIENTED TECHNOLOGY

At the core of MWO and VSS capability is advanced object-oriented technology. This technology results in software that is compact, fast, reliable, and easily enhanced with new technology as it becomes available.

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I N T R O D U C I N G A W R D E S I G N E N V I R O N M E N T

About This Guide1

ABOUT THIS GUIDE

This Getting Started Guide is designed to get you up and running quickly in the AWR Design Environment and to show you Microwave Office and VSS capabilities through working examples.

ASSUMPTIONS

It is assumed that you are familiar with Microsoft® Windows® and have a working knowledge of basic system design and analysis.

This document is available as a PDF file on your Program Disk (Getting Started.pdf), or you can download it from the AWR website at:

www.mwoffice.com

If you are viewing this guide as online Help and intend to work through the examples, you should obtain and print out the PDF version for your convenience.

CONTENTS OF THIS GUIDE

Chapter 2 provides the basic installation procedures.

Chapter 3 provides an overview of the AWR Design Environment including the basic menus, windows, components and commands.

Chapters 4, 5, 6, and 7 take you through hands-on examples that show you how to use Microwave Office to create circuit designs.

Chapters 8, 9, and 10 take you through hands-on examples that show you how to use VSS to create system simulations and to incorporate Microwave Office circuit designs.

CONVENTIONS USED IN THIS GUIDE

This guide uses the following typographical conventions:

Item Convention

Anything that you select (or click on) in the AWR Design Environment, like menu items, button names, and dialog box option names

Shown in a bold type. Nested menu selections are shown with a �>� to indicate that you select the first menu item and then select the second menu item:

Choose File > New Project

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I N T R O D U C I N G A W R D E S I G N E N V I R O N M E N TGetting Additional Information

GETTING ADDITIONAL INFORMATION

There are several resources available for additional information and technical support on MWO and VSS.

DOCUMENTATION

Documentation for MWO includes:

� What�s New in 2002? presents the new or enhanced features, elements, and measurements for this release. Available via the Start button Programs > AWR Suite 2002 menu.

� Microwave Office User Guide describes how to use the Microwave Office windows, menu choices, and dialog boxes to perform linear, nonlinear, and EM design, layout, and simulation, and discusses related concepts.

� Microwave Office Element Catalog (Volumes 1 and 2) provides complete reference information on all of the electrical elements that you use to build schematics.

� Microwave Office Measurement Reference provides complete reference information on the �measurements� (i.e., computed data such as gain, noise, power, or voltage) that you can choose as output for your simulations.

� MWO/VSS Installation Guide (available on your Program Disk (as install.pdf) or downloadable from the Applied Wave Research website at www.mwoffice.com under Support) describes how to install the AWR Design Environment and configure it for locked or floating licensing options. It also provides licensing configuration troubleshooting tips.

Any text that you enter using the keyboard

Shown in a bold type within quotation marks:Enter �my_project� in Project Name.

Keys or key combinations that you press

Shown in a bold type with initial capitals. Key combinations are shown with a �+� to indicate that you press and hold the first key while pressing the second key:

Press Alt+F1.

Item Convention

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I N T R O D U C I N G A W R D E S I G N E N V I R O N M E N T

Getting Additional Information1

� Known Issues (available on your program disk as KnownIssues.htm) lists the known issues for this release.

Documentation for VSS includes:

� Visual System Simulator System Block Catalog provides complete reference information on all of the system blocks that you use to build systems.

� Visual System Simulator Measurement Reference provides complete reference information on the measurements you can choose as output for your simulations.

ON-LINE HELP

All AWR documentation is available as on-line Help.

To access online Help choose Help from the main menu or press F1 anytime you are working within the AWR Design Environment. Context sensitive help is available for elements and system blocks in the Element Browser and within schematics or system diagrams. Context sensitive Help is available for measurements from the Add/Modify Measurements dialog box.

WEBSITE SUPPORT

Support is also available from the Applied Wave Research website at www.mwoffice.com. You can go directly to the site from the AWR Design Environment Help menu. The Support page provides the following:

� Frequently Asked Questions (FAQs) from MWO and VSS users

� Information about the mailing list set up for MWO and VSS customers

� Application Notes (e.g., technical abstracts, feature descriptions) for the advanced user

� A list of known issues

� Options to download VSS and MWO documentation

� A list of on-site training events.

TECHNICAL SUPPORT

Technical Support is available Monday-Friday, 9am-6pm, PST.

Phone: 310.726.3000 Fax: 310.726.3005 E-mail: support@mwoffice.

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .INSTALLING MWO/VSS 2

This chapter describes how to install Microwave Office (MWO) and Visual System Simulator (VSS). You can install them as standalone applications or together as integrated partners within the AWR Design Environment. Procedures also include installing vendor libraries and obtaining a FLEXlm® locked license with a software-based key.

The installation procedures are intended for evaluators and licensed users who wish to install VSS and Microwave Office with a FLEXlm license dedicated to their particular machine. FLEXlm is a robust, long-term licensing scheme that you can configure for floating licensing, and for hardware-based keys. For alternative licensing configurations, see the MWO/VSS Installation Guide on your Program Disk (install.pdf). You can also download this guide from the AWR website at www.mwoffice.com. The file is located under Support.

INSTALLATION OVERVIEW

The AWR Design Environment software is shipped on a program CD-ROM for installation. The installation program installs Microwave Office, Visual System Simulator, and optionally the vendor libraries.

Licensing and Available FeaturesYou may have purchased a complete MWO/VSS license with full functionality (i.e., linear simulator, nonlinear simulator, EM simulator, and layout tool), or you may have purchased a license for one or more features. In either case, the complete application is installed and your license determines the specific MWO and/or VSS functions that are available to you. The program is installed by default in C:\Program Files\AWR\AWR2002.

Installing Downloaded VersionsIf you are installing the program from the Applied Wave Research website (www.mwoffice.com), you can only download the Microwave Office and VSS applications; the complete vendor libraries are available only on the Program

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I N S T A L L I N G M WO / V S S

Preparing for Installation2

Disk. However, the downloaded Microwave Office and VSS applications include a minimal set of libraries so that you can work through the examples in this guide. You can access additional XML libraries from within the AWR Design Environment via the Element Browser and the AWR website.

In Case of Installation ErrorsIf installation aborts due to an error, ensure the machine�s TEMP environment variable points to an existing directory. To set environment variables, see the MWO/VSS Installation Guide (install.pdf on your Program Disk, or under Support at www.mwoffice.com.)

PREPARING FOR INSTALLATION

Before you start the installation do the following:

1 Make sure the machine on which you wish to install the software meets the following hardware and software requirements:

� Pentium® PC, 200MHz, 64MB RAM, 200MB1 available disk space.

� Microsoft® Windows® 2000, NT4®, ME, XP, or 98. Windows 2000 is the preferred operating system for Microwave Office.

� Microsoft Internet Explorer Version 5.0 or later, including Web Browser2, Help, and Visual Basic scripting support. To install Explorer, go to the Microsoft website at http://www.microsoft.com/windows/IE, or insert the Program Disk into the CD-ROM drive and run D:\Tools\ie6\IE6SETUP.EXE, where D: is the CD-ROM drive designation.

2 If you are installing an update to Microwave Office as well as installing VSS, back up any custom libraries you have stored in the Microwave Office Library directory and any .dll files you have stored in the Microwave Office cells or models directories.

1. Depending on which vendor libraries are being installed, additional space may be required.2. If you do not want the Microsoft Web Browser to be your default internet browser, you must choose to not

associate file types via the Advanced setup options when you install Internet Explorer. Note that youmust still have the Web Browser installed.

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I N S T A L L I N G M WO / V S SInstallation Procedure

3 If you are installing a major version upgrade to Microwave Office (e.g., Version 4.0 to Version 5.0), retain your existing version until you have verified that your projects are working successfully in the new version. (To uninstall Microwave Office, use �Add/Remove Programs� in the Windows Control Panel, then reboot.)

INSTALLATION PROCEDURE

You can specify an Express or a Custom installation from the installation Welcome screen. The default Express installation excludes prompts for specifying the information discussed in step 3.

To perform a Custom installation of the AWR Design Environment:

1 If you have the program CD-ROM, place it into the CD-ROM drive. When the AWR Design Environment splash screen displays, follow the prompts and instructions. If the Welcome dialog does not display, explore the program CD-ROM and run the setup.exe program.

2 If you have downloaded MWO and VSS from www.mwoffice.com, browse to the folder in which you downloaded the software, and run the setup program to display the installation Welcome dialog.

3 As you proceed with a Custom installation, consider these points:

� When asked if you wish to back up replaced files, note that backups are necessary only if you have modified files in your previous MWO/VSS version or stored any design files in the installation directory tree.

� When asked to select the options shown in the following table, make your selections based on the following information.

Option Description

Select Default Process Choose the default units to use in schematics and layouts within Microwave Office (as well as affect the default sizes for components such as transmission lines). By default, this is set to microns. Note that you can alternatively set this default within the Microwave Office program; see the Microwave Office User Guide for details.

Register File Extensions Select this check box to specify that files with a .emp, .em, .sch, or .net extension are opened in the AWR Design Environment. If you use another schematic tool or program that uses these extensions, you may want to disable this option. This check box is selected by default.

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I N S T A L L I N G M WO / V S S

Installation Procedure2

� When prompted to enter the name of the program group in the Start menu to which you want to add the AWR 2002 icons, note that �AWR Suite 2002� is the default choice. If you accept the default choice, you will start the program by clicking the Start button on your desktop and then choosing Programs > AWR Suite 2002 > AWR Design Environment.

� When prompted to create one or more Start menu shortcuts, choose from the following list of AWR product numbers based on the product feature set you have purchased.

If you have an evaluation license, leave all of the boxes unselected to create the appropriate default shortcut.

� When asked if you want to install the vendor libraries (this option is not available if you are installing a downloaded version of the software), go on to Step 2 in �Installing the Vendor Libraries� if you choose Yes.

4 When installation is complete, return to the AWR Design Environment splash screen and click Exit to close the screen.

Option Description

MWO-228;VSS-100 Visual System Simulator and full version of Microwave Office

VSS-100 Stand alone version of Visual System Simulator

MWO-228 linear, nonlinear, and EM simulators, and layout; design rule checking, ability to work with layout components having more than two layers, and access to foundry libraries

MWO-225 linear, nonlinear, and EM simulators, and layout

MWO-205 linear and nonlinear simulators, and layout

MWO-200 linear and nonlinear simulators

MWO-125 linear and EM simulators, and layout

MWO-120 linear and EM simulators

MWO-105 linear simulator and layout

MWO-100 linear simulator

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I N S T A L L I N G M WO / V S SInstalling the Vendor Libraries

INSTALLING THE VENDOR LIBRARIES

The AWR Design Environment includes vendor libraries for literally thousands of electrical components that you can use in your designs. To install the vendor libraries1, use the following procedure.

1 If you have the program CD, place it into the CD-ROM drive. When the AWR Design Environment 2002 splash screen displays, follow the prompts and instructions.

2 If the installation Welcome dialog does not display, explore the program CD-ROM and run the setup.exe program.

3 As you proceed with installation, consider these points:

� When asked whether you wish to install all vendor libraries or only specific vendor libraries, it is strongly suggested that you install only the libraries you will need. Although the libraries themselves are nominally 170 MB or so, they may consume considerably more space than that depending on your disk configuration.

� As you select the libraries to install, the required and remaining disk space are updated as you add each new library.

4 When vendor library installation is complete, return to the AWR Design Environment splash screen and click Exit. The vendor libraries are installed by default in C:\Program Files\AWR\AWR2002.

OBTAINING YOUR FLEXLM LICENSE

The AWR Design Environment supports FLEXlm floating2 licensing and hardware-based3 keys. If you want to configure your site for FLEXlm floating licensing, and/or if you want to use hardware-based keys, see the MWO/VSS

1. Vendor libraries can only be installed from the Program Disk, and cannot be downloaded from theAWR website. Many XML libraries, however, can be accessed from within the AWR Design Envi-ronment (through the Element Browser via the AWR website) regardless of whether the application isdownloaded or installed from the Program Disk.

2. Floating licensing allows multiple users to share a license over a network via a client-server architecture,whereas locked licensing dedicates a license to a particular machine.

3. Hardware-based keys are calculated from an AWR-supplied hardware dongle serial number. Such alicense can be transferred between machines simply by moving the dongle.

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I N S T A L L I N G M WO / V S S

Obtaining Your FLEXlm License2

Installation Guide under Support at www.mwoffice.com, or on your Program Disk (install.pdf).

To obtain a FLEXlm locked license using a software-based key:

1 Click the Start button on your desktop, and choose Programs > AWR Suite 2002 > AWR Design Environment. If the AWR Design Environment was not configured during installation to display from your Start menu, start it by double-clicking My Computer on your desktop, opening the folder where you installed the program and double-clicking on MWOffice.exe.

2 The following AWR License Configuration dialog box displays.

3 To obtain a valid license file from Applied Wave Research, click on the appropriate button under Registration and follow the instructions.

4 You will receive your license within two business days. When you receive it, rename it to awr.lic and place it into the program directory.

W H A T � S N E X T ?

The next chapter describes the basic windows and menus you use to work with MWO and VSS in the AWR Design environment. Following chapters provide hands-on examples you can go through to learn the basics and quickly start using Microwave Office and Visual System Simulator.

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .AWR DESIGN ENVIRONMENT 3

This chapter describes the windows, menus and basic operations for working in the AWR Design Environment to perform the following operations:

� Creating projects to organize and save your designs

� Creating system diagrams, circuit schematics and EM structures

� Placing circuit elements into schematics

� Placing system blocks into system diagrams

� Incorporating and tuning subcircuits into the system diagrams and schematics

� Running simulations for schematics and system diagrams

� Displaying output graphs

� Creating layouts

STARTING AWR PROGRAMS

To start the AWR Design Environment:

1 Click Start on your desktop.

2 Choose Programs > AWR Suite 2002 > AWR Design Environment. The following AWR Design Suite main window displays.

If the AWR Design Environment was not configured during installation to display in your Start menu, start the application by double-clicking the My Computer icon on your desktop, opening the drive and folder where you installed the program, and double-clicking on MWOffice.exe, the Microwave Office application.

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A W R D E S I G N E N V I R O N M E N T

AWR Environment Components3

AWR ENVIRONMENT COMPONENTS

The AWR Design Environment main window contains the windows, components, menu selections and tools you need to create linear and nonlinear schematics, set up EM structures, generate circuit layouts, create system diagrams, perform simulations, and display graphs. Most of the basic procedures apply to both Microwave Office (MWO) and Visual System Simulator (VSS). The major components of the AWR Design Environment are:

Component Description

menu A set of menus located along the top of the window for performing a variety of MWO and VSS tasks.

Menus

Project Browser

Workspace

Toolbar

Tabs

Title bar

System Diagrams

Circuit Schematics

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A W R D E S I G N E N V I R O N M E N TAWR Environment Components

Many of the functions and commands can be invoked from the menus and the on the toolbar, and in some cases by right-clicking on a node in the Project Browser. This guide may not describe all of the ways to invoke a specific task.

toolbar A row of buttons located just below the menu that provides shortcuts to frequently used commands such as creating new schematics, performing simulations, or tuning parameter values or variables.The buttons available depend on the functions in use and the active window within the design environment. Position the cursor over a button for a description of the button.

Project Browser Located in the left column of the window, this is the complete collection of data and components that define the currently active project. Items are organized into a tree-like structure of nodes and include schematics, system diagrams and EM structures, simulation frequency settings, and output graphs. The Project Browser is active when the AWR Environment first opens. Right-click on a group in the Project Browser to access menus of relevant commands.

Element Browser Contains a comprehensive inventory of circuit elements for building your schematics and system blocks for building system diagrams for simulations. The Element Browser displays in the left column in place of the Project Browser when you click the Elem tab at the lower left of the window.

workspace The area in which you design schematics and diagrams, draw EM structures, view and edit layouts, and view graphs. You can use the scrollbars to move around the workspace. You can also use the zoom in and zoom out options from the View menu. You can also cut, copy and paste elements, ports and wires from one diagram or schematic or project to another.

tabs A set of tabs located at the lower left of the window that allow you to switch the contents of the left column of the window from Project Browser (i.e., Proj) to Element Browser, Variable Browser, or Layout Manager. Click the Elem tab to display the Element Browser and to access a comprehensive inventory of circuit elements and system blocks for simulation. Click the Var tab to tune or optimize parameter values or variables for schematic elements in the active project. Click the Layout tab to specify options for viewing and drawing layout representations and to create new layout cells.

Component Description

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A W R D E S I G N E N V I R O N M E N T

Basic Operations3

BASIC OPERATIONS

This section highlights the windows, menu choices, and commands for creating simulation designs and projects in the AWR Design Environment.

Working With ProjectsThe first step in building and simulating a design is to create a project. You use a project to organize and manage your designs and everything associated with them in a tree-like sructure.

CREATING PROJECTS

Because MWO and VSS are fully integrated in the AWR Environment, you can start a project based on a system design using VSS, or on a circuit design using MWO. The project may ultimately combine both VSS and MWO elements. All of the components and elements in the project can be viewed in the Project Browser. Modifications are automatically reflected in the relevant elements.

PROJECT CONTENTS

A project can include any set of designs and one or more linear schematics, nonlinear schematics, EM structures or system level blocks. A project can include anything associated with the designs, such as global parameter values, imported files, layout views, and output graphs. When you save a project, everything associated with it is automatically saved. AWR projects are saved as *.emp files.

CREATING, OPENING, AND SAVING PROJECTS

When you first start the AWR Design Environment, a default empty project called �Untitled Project� is loaded. Only one project can be active at a time. The name of the active project displays in the main window title bar.

After you create (name) a project, you can create your designs. You can perform simulations to analyze the designs and see the results on a variety of graphical forms that you specify. Then, you can tune or optimize parameter values and variables as needed to achieve the response you want. You can generate layout representations of the designs, and output the layout to a DXF, GDSII, or Gerber file.

To create a new project choose File > New Project. Name the new project by choosing File > Save Project As. The name is reflected in the title bar.

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A W R D E S I G N E N V I R O N M E N TBasic Operations

To open an existing project, choose File > Open Project. To save the current project, choose File > Save Project.

Working With Schematics and Netlists in MWOA schematic is a graphical representation of a circuit; a netlist is a text-based description. A Microwave Office project can include multiple linear and nonlinear schematics and netlists.

To create a new schematic or netlist, right-click on Circuit Schematics in the Project Browser, and choose New Schematic or New Netlist.

After you specify a schematic or netlist name, a schematic or netlist window opens in the workspace and the Project Browser displays the new schematic or netlist as a subnode of Circuit Schematics. Subgroups of the new schematic or netlist contain all of the parameters and options that define and describe the schematic or netlist. In addition, the menu and toolbar display new choices particular to building and simulating schematics or netlists.

Create new project

Open existing project

Save current project

Name new project

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Basic Operations3

Working with System DiagramsA VSS project can include multiple system diagrams. To create a new system diagram, right-click on System Diagrams in the Project Browser, and choose New System Diagram.

You are prompted to name the new diagram.

After you name the system diagram, a window opens in the workspace and the Project Browser displays the new system diagram. Subnodes of the system diagram also display in the Project Browser and contain all of the parameters and options that define and describe the system diagram. After you name the system diagram, the menus and toolbar display new selections and buttons for building and simulating systems.

Right-click to create new system diagram

System diagram opens in the workspace

Right-click then choose New Schematic

Create new netlist

Schematic window(or netlist window)opens in the workspace

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A W R D E S I G N E N V I R O N M E N TBasic Operations

The Element BrowserThe Element Browser gives you access to a comprehensive database of hierarchical groups of circuit elements for schematics and system blocks for system diagrams. The Library and Data folders in the Element Browser provide a wide range of electrical models and S-parameter files from manufacturers.

Circuit elements include models, sources, ports, probes, measurement devices, data libraries, and model libraries that can be placed in a circuit schematic for linear and non-linear simulations.

System blocks include channels, math tools, meters, subcircuits, and other models for system simulations.

� To view elements or system blocks, click the Elem tab in the lower left window. The Element Browser replaces the Project Browser window.

� To expand and contract the model categories, click the + and - symbols to view the desired subcategory, such as Capacitor or Inductor. The available models display in the lower window pane.

� To place a model into a schematic or system diagram, simply click and drag it into the schematic or system diagram window, release the mouse button, right-click to rotate it if needed, position it, and click to place it.

� To edit model parameters, simply double-click on the element graphic in the schematic or system diagram window. A dialog box displays for you to specify new parameter values.

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ADDING SUBCIRCUITS TO SCHEMATICS

Subcircuits allow you to construct hierarchical circuits by including a circuit block in a schematic. The circuit block can be a schematic, a netlist, an EM structure, or a data file.

� To add a subcircuit to a schematic, click on Subcircuits in the Element Browser. The available subcircuits display in the lower window pane. These include all of the schematics, netlists, and EM structures associated with the project, as well as any imported data files defined for the project.

� To add a data file as a subcircuit, it must first be imported and added to the project as an node. To do so, choose Project > Add Data File. Any imported data files are automatically shown in the list of available subcircuits in the Element Browser.

� To place the desired subcircuit, simply click and drag it into the schematic window, release the mouse button, position it, and click to place it.

� To edit subcircuit parameters, select the subcircuit in the schematic window, right-click, and choose Open Subcircuit. Either a schematic, netlist, EM structure, or data file opens in the workspace and can be

Expand and contract, then click desired subcategory

Click Elem tab to display Element Browser

Drag desired modelinto schematic window

Buttons for adding ports and ground

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edited in the same way that you would edit the individual circuit block types.

ADDING PORTS AND WIRES TO SCHEMATICS AND DIAGRAMS

To add ports to a schematic or system diagram, expand the Ports category in the Element Browser. Under Circuit Elements or System Blocks, click the desired Port subcategory, for example, Volterra. The available models display in the lower window pane. Drag the port into the schematic or system diagram window, right-click to rotate it if needed, position it, and click to place it.

For a shortcut when placing ports and ground, click the Port or Ground buttons on the toolbar, position the port or ground, and click to place it.

CONNECTING ELEMENT AND SYSTEM BLOCK NODES

To connect element or system block nodes with a wire, position the cursor over a node. The cursor displays as a wire coil symbol. Click at this position to mark the beginning of the wire and slide the mouse to a location where a bend is needed. Click again to mark the bend point. You can make multiple bends. Terminate the wire by clicking on another element node or on top of another wire. To cancel the wire, press the Esc key.

EDITING PORT PARAMETERS

To edit port parameters, double-click on the port in the schematic or diagram windows to display a dialog box in which you can specify new parameter values.

ADDING DATA TO NETLISTS

When you create a new netlist, an empty netlist window opens into which you type a text-based description of a schematic. Netlist data is arranged in blocks in a particular order, where each block defines a different attribute of an element, such as units, equations, or element connections. For more information on creating netlists, see the Microwave Office User Guide.

CREATING EM STRUCTURES

EM structures are arbitrary multi-layered electrical structures such as spiral inductors with air bridges.

To create a new EM structure, right-click on EM Structures in the Project Browser, and choose New EM Structure.

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After you specify an EM structure name, an EM structure window opens in the workspace and the Project Browser displays the new EM structure under EM Structures. Subnodes of the new EM structure contain all of the parameters and options that define and describe the EM structure. In addition, the menu and toolbar display new choices particular to drawing and simulating EM structures.

ADDING EM STRUCTURE DRAWINGS

Before you draw an EM structure, you must define an enclosure. The enclosure specifies things such as boundary conditions and dielectric materials for each layer of the structure.

To define an enclosure, double-click Enclosure under your new EM structure in the Project Browser to display a dialog box in which you can specify the required information.

After you specify the enclosure, you can create drawings by accessing options from the Draw menu to draw components such as rectangular conductors, vias, and edge ports.

Create new EM structure

EM structure window opens in the workspace

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You can view EM structures in 2D and 3D by using the View menu, and you can view currents and electrical fields using the Animate menu.

Creating a Layout with MWOA layout is a view of the physical representation of a circuit, in which each component of the schematic is assigned a layout cell. In the object-oriented AWR environment, layouts are tightly integrated with the schematics and EM structures that they represent and are simply another view of the same circuits. Any modification made to a schematic or EM structure is automatically and instantly reflected in its corresponding layout.

To create the layout representation of a schematic, click on the schematic window to make it active, and choose Schematic > View Layout. A layout window displays (overlaying the schematic window) with an automatically-generated layout view of the schematic.

As a shortcut, click the Layout button on the toolbar to view the layout of a schematic.

Shortcuts for drawing conductors, vias, and ports

Draw conductors, vias, and ports

Double-click to definean enclosure

Display 2D and 3D views of the structure

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The resulting layout contains layout cells representing electrical components floating in the layout window. Choose Edit > Snap Together to snap the faces of the layout cells together. The following figure shows the layout view from the previous figure after a snap.

When you choose Schematic > View Layout, default layout cells are automatically assigned for common electrical components such as microstrip, coplanar waveguide, and stripline elements. Components of the schematic that do not map to default layout cells display in blue in the schematic window after the layout has been generated; components that do have default layout cells display in magenta. For components without default layout cells defined, you must create them or import them via the Layout Manager. For more information see Using the Layout Manager on page 3-13.

You can draw in the layout window using the draw tools to build substrate outlines, draw DC pads for biasing, or to add other elements.

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MODIFYING LAYOUT ATTRIBUTES AND DRAWING PROPERTIES

To modify layout attributes and drawing properties, as well as create new layout cells for elements that do not have default cells, click the Layout tab in the lower left window. The Layout Manager replaces the Project Browser window.

USING THE LAYOUT MANAGER

The Layer Setup group in the Layout Manager defines layout attributes such as drawing properties (line color, layer pattern, etc.), 3D properties (thickness, etc.), and layer mappings. To modify layer attributes, right-click Layer Setup and choose Edit Drawing Layers. You can also import a layer process file (LPF) to define these attributes by right-clicking Layer Setup and choosing Import Process Definition.

The Cell Libraries group in the Layout Manager allows you to create artwork cells for elements that do not have default layout cells. The powerful Cell Editor includes such features as coordinate entry, boolean operations for subtracting and uniting shapes, array copy, arbitrary rotation, grouping, and alignment tools. You can also import artwork cell libraries such as GDSII or DXF into the AWR Design Environment.

Once you have created or imported cell libraries, you can browse through the libraries and select the desired layout cells to include in your layout. Click the + and - symbols to expand and contract the cell libraries, and click the desired library. The available layout cells display in the lower window pane. To place a

Right-click to import a cell library or create your own using a Cell Editor

Click the Layout tab todisplay Layout Manager

Right-click to modify layout attributes or import an LPF

Activate layers for viewing and drawing

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cell into the layout window, simply click and drag it, release the mouse button, position it, and click to place it..

You can import layouts as GDSII, DXF, Gerber, or PADS files. To export a layout, click the layout window to make it active, and choose Layout > Export Layout.

Creating Output Graphs and MeasurementsYou can view the results of your circuit and system simulations in various graphical forms. Before you perform a simulation, you create a graph and specify the data, or measurements, that you wish to plot. Measurements can include for example, gain, noise or scattering coefficients.

To create a graph, right-click on Graphs in the Project Browser, and choose Add Graph to display a dialog box in which to specify a graph name and type. An empty graph displays in the workspace and the graph name displays under Graphs in the Project Browser. The following graph types are available:

Graph Type Description

Rectangular Displays the measurement on an x-y axis, usually over frequency.

Constellation Displays the in-phase (real) versus the quadrature (imaginary) component of a complex signal.

Expand and contract, thenclick desired library

Drag layout cell intolayout window

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To specify the data that you wish to plot, right-click the new graph name in the Project Browser, and choose Add Measurement. A dialog box allows you to choose from a comprehensive list of measurements.

Performing SimulationsTo run a simulation on the active project, choose Simulate > Analyze. The simulation is run automatically on the entire project, using the appropriate simulator (for example, linear simulator, harmonic balance or Volterra-series nonlinear simulator, or 3D-planar EM simulator) for the different pieces of the project.

SETTING SIMULATION FREQUENCY

To set the simulation frequency, double-click the Project Options node in the Project Browser, or choose Options > Project Options and then specify frequency values in the dialog box.

VSS SYSTEM SIMULATIONS

To set simulation frequency, double-click the System Diagrams node in the Project Browser, or choose Options > Default System Options and then specify frequency values in the dialog box.

Smith Chart Displays passive impedance or admittances in a reflection coefficient chart of unit radius.

Polar Displays the magnitude and angle of the measurement.

Histogram Displays the measurement as a histogram.

Antenna Plot Displays the sweep dimension of the measurement as the angle and the data dimension of the measurement as the magnitude.

Tabular Displays the measurement in columns of numbers, usually against frequency.

Graph Type Description

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When the simulation is complete, you can view its output on the graphs and then easily tune and/or optimize as needed.

TUNING SIMULATIONS

The real-time tuner lets you see the effect on the simulation as you tune. The optimizer lets you see circuit parameter values and variables change in real-time as it works to meet the optimization goals that you have specified.

As a shortcut, click the Tune Tool button on the toolbar and select the parameters you wish to tune, then click the Tuner button to tune the values. As you tune or optimize, the schematics and associated layouts are automatically updated. When you re-run the simulation, only the modified portions of the project are recalculated..

Select the number of samples per symbol

Equation describing parameter relationships

100 300 500 700 900 1000Frequency (MHz)

s21and s11

-60

-50

-40

-30

-20

-10

0

DB(|S[1,1]|)lpf

DB(|S[2,1]|)lpf

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Adding Subcircuits to System DiagramsSubcircuits allow you to construct hierarchical systems and to import results of circuit simulation directly into the system block diagram.

� To add a subcircuit to a system, first choose Project > Add System Diagram > New System Diagram or Import System Diagram and then click on Subcircuits under System Blocks in the Element Browser.

� The available system subcircuits display in the lower window pane.

� To place the desired subcircuit, simply click and drag it into the system diagram window, release the mouse button, position it, and click to place it.

� To edit subcircuit parameters, select the subcircuit in the system diagram window, right-click, and choose Open Subcircuit.

ADDING PORTS AND WIRES TO SYSTEMS

To add a system diagram as a subcircuit to another system diagram, you must first add ports to the system that is designated as a subcircuit. There are two ways to add ports to a system.

To place ports, click the Port button on the toolbar, position the port and click to place it, or click on Ports under System Blocks in the Element Browser and connect an input port (PORTDIN) and an output port (PORTDOUT) in the appropriate system.

To connect two block nodes with a wire, position the cursor over a node in the system diagram window. The cursor displays as a wire coil symbol. Click at this position to mark the beginning of the wire and slide the mouse to where you want a point. Click again to mark the bend point. You can make multiple bends. Terminate the wire by clicking on another element node or on another wire. To cancel the wire, press the Esc key.

Scripts and WizardsScripts and wizards, new features of Microwave Office, allow you to automate and extend Microwave Office functions in a non-proprietary manner. These features are implemented via the Microwave Office API, a COM automation-compliant server that can be programmed in any non-proprietary language such as C, Visual Basic�, or Java.

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Scripts are Basic programs that you can write to do things such as automate schematic-building tasks within Microwave Office.

Wizards are Dynamic Link Library (DLL) files which you can author to create add-on tools for Microwave Office, for example, a filter synthesis tool.

Scripts and wizards display as Scripting and Wizards in the Project Browser.

USING ONLINE HELP

Online Help provides information on the windows, menu choices, and dialog boxes in the AWR Design Environment, as well as design concepts.

To access Help, choose Help from the menu bar or press F1 anywhere in the program. The following context-sensitive Help is also available:

� Context-sensitive Help buttons in each dialog box.

� Context-sensitive Help for each element or system block in the Element Browser, accessed by selecting a model and pressing Alt+F1, or by right-clicking on a model and choosing Element Help.

� Context-sensitive Help for using the AWR script development environment, accessed by selecting a keyword (i.e., object, object model, or Visual Basic syntax), and pressing F1.

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .USING THE LINEAR SIMULATOR 4

Linear simulators use nodal analysis to simulate the characteristics of a circuit. Linear simulations are used for circuits such as low noise amplifiers, filters, and couplers whose elements can be characterized by an admittance matrix. Linear simulators typically generate measurements such as gain, stability, noise figure, reflection coefficient, noise circles, and gain circles.

LINEAR SIMULATIONS IN MICROWAVE OFFICE

The Microwave Office linear simulator is architected using object-oriented techniques that enable fast and efficient simulations of linear circuits. One of its trademarks is a real-time tuner that allows you to see resulting simulations as you tune. It also allows you to perform optimization and yield analysis.

The following example illustrates some of the key features of the Microwave Office linear simulator.

HOW TO CREATE A LUMPED ELEMENT FILTER

This example demonstrates how to use Microwave Office to simulate a basic lumped element filter using the linear simulator. It includes the following steps:

� Creating a schematic

� Adding graphs and measurements

� Analyzing the circuit

� Tuning the circuit

� Creating variables

� Optimizing the circuit

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CREATE A NEW PROJECT

To create a new project:

1 Choose File > New Project.

2 Choose File > Save Project As. The Save As dialog box displays.

3 Type a project name (for example, �linear_example�), and click Save.

SET DEFAULT PROJECT UNITS

To set default project units:

1 Choose Options > Project Options. The Project Options dialog box displays.

2 Click the Global Units tab.

3 Modify the units by clicking the arrows to the right of the display boxes so that they match those in the figure below, and click OK.

.

CREATE A SCHEMATIC

To create a schematic:

1 Choose Project > Add Schematic > New Schematic. The Create New Schematic dialog box displays.

2 Type �lpf �, and click OK. A schematic window displays in the workspace and the schematic displays under Circuit Schematics in the Project Browser.

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PLACE ELEMENTS IN A SCHEMATIC

Use the scroll arrows along the right and bottom of the schematic window to view different portions of the schematic as you work.

To place elements in a schematic:

1 Click the Elem tab in the lower left window to display the Element Browser.

2 Expand Lumped Element in the Element Browser by clicking the + symbol to the left of the icon.

3 Click Inductor under Lumped Element to display a set of inductor models in the lower pane.

4 Click the IND model, and holding the mouse button down, drag it into the schematic, then release the mouse button.

5 Position the element as shown in the figure below, and then click to place it.

HINT: As a shortcut, to connect one element to another element in the schematic, position the element so that its node snaps to the node of the other element. When properly connected, the node displays with a small blue square. If you did not connect properly the first time, just click the element graphic, hold the mouse button down, and drag the element to its proper place.

6 Repeat steps 4 and 5 three times, aligning and connecting each inductor as shown below.

Element models

Element Browser

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7 Now click on Capacitor under Lumped Element in the Element Browser to display a set of capacitor models in the lower pane.

8 Click the CAP model, and holding the mouse button down, drag it into the schematic, release the mouse button, right-click to rotate the element, position it as shown in the figure below, and click to place it.

9 Repeat Step 8 twice, aligning and linking each capacitor as shown.

CONNECT THE WIRES

To connect the bottom nodes of the three capacitor elements together:

1 Place the cursor over the bottom node of CAP C1. The cursor displays as a wire coil symbol, as shown below.

2 Click, then drag the wire past the bottom node of CAP C2, then onto the bottom node of CAP C3, and click to place the wire.

IND

L=ID=

1 nHL1

IND

L=ID=

1 nHL2

IND

L=ID=

1 nHL3

IND

L=ID=

1 nHL4

IND

L=ID=

1 nHL1

IND

L=ID=

1 nHL2

IND

L=ID=

1 nHL3

IND

L=ID=

1 nHL4

CAP

C=ID=

1 pFC1

CAP

C=ID=

1 pFC2

CAP

C=ID=

1 pFC3

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PLACE PORTS ON A NODE

To place a port on a node:

1 Choose Schematic > Add Port.

2 Slide the cursor onto the schematic, position the port on the first inductor node, and click the mouse to place it.

3 Repeat Step 1 to add a port to the right-most inductor, but click the right mouse button two times to rotate the port 180-degrees before you place it.

As a shortcut, you can also click the Port button on the toolbar, slide the cursor into the schematic, position the port, and click again to place the port on a node.

PLACE GROUND ON A NODE

To place ground on a node:

1 Choose Schematic > Add Ground.

2 Slide the cursor onto the schematic, position the ground on the bottom node of CAP C1, and click to place it.

IND

L=ID=

1 nHL1

IND

L=ID=

1 nHL2

IND

L=ID=

1 nHL3

IND

L=ID=

1 nHL4

CAP

C=ID=

1 pFC1

CAP

C=ID=

1 pFC2

CAP

C=ID=

1 pFC3

IND

L=ID=

1 nHL1

IND

L=ID=

1 nHL2

IND

L=ID=

1 nHL3

IND

L=ID=

1 nHL4

CAP

C=ID=

1 pFC1

CAP

C=ID=

1 pFC2

CAP

C=ID=

1 pFC3

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

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EDIT ELEMENT PARAMETERS

To edit the element parameters:

1 Double-click the Ind L1 graphic in the schematic window. The Element Options dialog box displays.

2 In the Inductance (L) row, enter �15� as the Value and click OK. The change is reflected in the schematic.

3 Follow Steps 1 and 2 to edit the inductor and capacitor values to match what is shown below. (To edit capacitor values, select C in the Parameters list box.)

As a shortcut, double-click on the parameter value in the schematic. An edit box displays for you to modify the parameter value directly on the schematic.

SPECIFY THE SIMULATION FREQUENCY

To specify the simulation frequency:

1 Click the Proj tab in the lower left window to activate the Project Browser.

2 Double-click Project Options in the Project Browser. The Project Options dialog box displays.

IND

L=ID=

1 nHL1

IND

L=ID=

1 nHL2

IND

L=ID=

1 nHL3

IND

L=ID=

1 nHL4

CAP

C=ID=

1 pFC1

CAP

C=ID=

1 pFC2

CAP

C=ID=

1 pFC3

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

IND

L=ID=

15 nHL1

IND

L=ID=

30 nHL2

IND

L=ID=

30 nHL3

IND

L=ID=

15 nHL4

CAP

C=ID=

8 pFC1

CAP

C=ID=

10 pFC2

CAP

C=ID=

8 pFC3

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

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3 Click the Frequency Values tab.

4 Type �100� in Start, �1000� in Stop, and �10� in Step, and then click Apply. The frequency range and steps you specified display in Current Range.

5 Click OK.

CREATE A GRAPH

To create a graph:

1 Right-click on Graphs in the Project Browser, and choose Add Graph. The Create Graph dialog box displays.

2 Type �s21 and s11� in Graph Name. Select Rectangular for Graph Type, and click OK. The graph displays in a window in the workspace and displays under Graphs in the Project Browser.

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ADD A MEASUREMENT

To add measurements:

1 Right-click �s21 and s11� in the Project Browser, and choose Add Measurement. The Add Measurement dialog box displays.

2 Select Port Parameters as the Meas. Type and S as the Measurement. Click on the arrow to the right of Data Source Name and select lpf. Click on the arrows to the right of To Port Index and From Port Index and select �1� for each. Select Mag. as the Complex Modifier, select the DB check box under Result Type, and then click Add to add the measurement.

Individual graphs display under Graphs

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3 Change the value in To Port Index to �2�, and click Add to add a second measurement.

4 Click Close. The measurements lpf:DB(|S[1,1]|) and lpf:DB(|S[2,1]|) display under s21 and s11 in the Project Browser.

ANALYZE THE CIRCUIT

To analyze the circuit:

1 Choose Simulate > Analyze. The simulation response displays on the graph.

As a shortcut, click the Analyze button on the toolbar to simulate the active project.

TUNE THE CIRCUIT

When you place the tune tool over a schematic element, the cursor displays as a cross icon to indicate that the parameter may be tuned.

To tune the circuit:

1 Click on the schematic window to make it active.

2 Click the Tune Tool button on the toolbar.

3 Move the cursor over the L parameter of IND L1. The cursor displays as a cross.

100 300 500 700 900 1000Frequency (MHz)

s21and s11

-50

-40

-30

-20

-10

0

DB(|S[1,1]|)lpf

DB(|S[2,1]|)lpf

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4 Click to activate the L parameter for tuning. The parameter displays in an alternate color.

5 Repeat Steps 2 through 4 for elements CAP C1, CAP C3, and IND L4.

6 Click on the graph window to make it active.

7 Choose Simulate > Tune. The Variable Tuner dialog box displays.

8 Click on a tuning button, and holding the mouse button down, slide the tuning bar up and down. Observe the simulation change on the graph as the variables are tuned.

9 Slide the tuners to the values shown below, and observe the resulting response on the graph of the tuned circuit.

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10 Click the X at the top right of the Variable Tuner dialog box to close it.

CREATE VARIABLES

Filters are typically symmetric circuits. To optimize the circuit, you must change some of the parameter values to variables.

To create variables:

1 Click on the schematic window to make it active.

2 Choose Schematic > Add Equation.

3 Move the cursor into the schematic. An edit box displays.

4 Position the edit window in the top area of the schematic window, and click to place it.

5 Type �Lin=15� in the edit box, and click the mouse outside of the edit box.

6 Repeat Steps 2 through 5 to create a second edit box, but type �Cin=8�, and click the mouse outside of the edit box.

7 Double-click the L parameter value of IND L1. An edit box displays. Type the value �Lin�.

8 Repeat Step 7 to change the L parameter of IND L4 to �Lin�, and the C parameters of CAP C1 and CAP C3 to �Cin�, as shown in the following figure.

100 300 500 700 900 1000Frequency (MHz)

s21and s11

-60

-50

-40

-30

-20

-10

0

DB(|S[1,1]|)lpf

DB(|S[2,1]|)lpf

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To enable variables Lin and Cin for optimization:

1 Click the Var tab in the lower left window.

2 Expand lpf in the Variable Browser by clicking the + symbol to the left of the icon.

3 Click lpf Equations. The lower window displays the variables Cin and Lin.

4 Select the O check box for both variables.

5 Click the lpf group in the upper window, and select the O check box corresponding to C2.

IND

L=ID=

Lin nHL1

IND

L=ID=

30 nHL2

IND

L=ID=

30 nHL3

IND

L=ID=

Lin nHL4

CAP

C=ID=

Cin pFC1

CAP

C=ID=

10 pFC2

CAP

C=ID=

Cin pFC3

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

Lin=15 Cin=8

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ADD OPTIMIZATION GOALS

When you set an optimization goal, it is specified in the same units set when the goal was first added.

To add optimization goals:

1 Click the Proj tab.

2 Right-click Optimizer Goals, and choose Add Opt Goal. The New Optimization Goal dialog box displays.

3 Select lpf:DB(|S[1,1]) as the Measurement. Select Meas < Goal as the Goal Type, deselect Max under Range, type �500� as the Stop value, type �-17� as the Goal, and then click OK.

4 Repeat Step 2, but select lpf:DB(|S[2,1]) as the Measurement, select Meas > Goal as the Goal Type, deselect Max under Range, type �500� as the Stop value, type �-1� as the Goal, and then click OK.

5 Repeat Step 2 again, but select lpf:DB(|S[2,1]) as the Measurement, select Meas < Goal as the Goal Type, deselect Min under Range, type �700� as the Start value, type �-30� as the Goal, and then click OK.

OPTIMIZE THE CIRCUIT

1 Choose Simulate > Optimize. The Optimize dialog box displays.

2 Click on the arrow to the right of Optimization Methods and select Random (Local), type �5000� in Maximum Iterations, and then click Start. The optimization runs.

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3 When the optimization is complete, click Close to exit the Optimize dialog box. View the final optimized response in the schematic and on the graph, as follows.

CREATING VECTOR VARIABLES

MWO has new equation functionality that enables you to optimize on subcircuits. The new string and vector variable features in the equation editor allow you to specify a vector of subcircuits that can be optimized. To demonstrate this new feature, the lpf schematic is copied, edited, and renamed to create the vector of subcircuits.

To create copies of the lpf schematic:

1 Click on the lpf schematic in the Project Browser, and holding the mouse button down, drag it onto Circuit Schematics and then release the mouse

IND

L=ID=

Lin nHL1

IND

L=ID=

30 nHL2

IND

L=ID=

30 nHL3

IND

L=ID=

Lin nHL4

CAP

C=ID=

Cin pFC1

CAP

C=ID=

11.06 pFC2

CAP

C=ID=

Cin pFC3

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

Lin=16.71 Cin=9.64

100 300 500 700 900 1000Frequency (MHz)

s21and s11

-60

-50

-40

-30

-20

-10

0

DB(|S[1,1]|)lpf

DB(|S[2,1]|)lpf

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button. A duplicate schematic named Copy of lpf is created. Repeat the process to create a second copy named Copy 2 of lpf.

2 Right-click Copy of lpf in the Project Browser, and choose Rename Schematic. Type �lpf2� in the Rename Data Source dialog box. Repeat this step to rename Copy 2 of lpf to lpf3. The resulting Project Browser displays as follows.

To modify element parameters in the lpf2 and lpf3 schematics (so that each schematic is different):

3 Open the lpf2 schematic. Edit the variables Lin and Cin to the following values.

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4 Open the lpf3 schematic. Edit the C parameter for CAP ID=C2 to the following value.

To create a new schematic which contains a subcircuit that references the three schematics:

5 Click the Proj tab to display the Project Browser. Right-click Circuit Schematics, and choose New Schematic. Type �Opt_w_subckt� in the Enter Schematic Name dialog box.

6 Click the Elem tab in the lower left window to display the Element Browser.

7 Click Subcircuits. Click on the lpf subcircuit, and holding the mouse button down, drag it into the schematic, release the mouse button, and click to place it.

IND

L=ID=

Lin nHL1

IND

L=ID=

30 nHL2

IND

L=ID=

30 nHL3

IND

L=ID=

Lin nHL4

CA P

C=ID =

Cin pFC1

CA P

C=ID=

11.06 pFC2

CAP

C =ID=

C in pFC 3

PORT

Z =P =

50 Ohm1

P ORT

Z =P=

50 Ohm2

Lin=9 Cin=8

IND

L=ID=

Lin nHL1

IND

L=ID=

30 nHL2

IND

L=ID=

30 nHL3

IND

L=ID=

Lin nHL4

CAP

C=ID=

Cin pFC1

CAP

C=ID=

13 pFC2

CAP

C=ID=

Cin pFC3

PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

Lin=16.71 Cin=9.64

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8 Place ports on the subcircuit as follows. For details, see �Place ports on a Node� on page 4-5.

To create a vector of subcircuits and an index variable to optimize:

9 Create the vector variable Xvector={"lpf3","lpf2","lpf"} in the schematic Opt_w_subcircuit as follows. For details, see �Create Variables� on page 4-11.

1 2

SUBCKT

NET=ID=

"lpf" S1 PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

1 2

SUBCKT

NET=ID=

"lpf" S1 PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

Xvector={"lpf3","lpf2","lpf"}

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10 Create the index variable X=Xvector[1] in the schematic, and change the NET parameter to X as follows. For details, see �Edit element parameters� on page 4-6.

OPTIMIZING WITH SUBCIRCUITS

The variable X=Xvector[1] references the lpf3 subcircuit. This subcircuit can be tuned or optimized over the vector of subcircuit elements by varying the index in the variable. It is important to note that the index (and not the actual element in the vector) is optimized and tuned.

1 Click s21 and s11 in the Project Browser, and holding the mouse button down, drag it onto Graphs and release the mouse button. A duplicate graph named Copy of s21 and s11 is created.

1 2

SUBCKT

NET=ID=

X S1 PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

Xvector={"lpf3","lpf2","lpf"}

X=Xvector[1]

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2 Right-click Copy of s21 and s11, and choose Rename Graph. Type �subckt opt� in the Rename Output Document dialog box.

3 Double-click the lpf:DB(|S[1,1]) measurement under the subckt opt graph in the Project Browser. A Modify Measurement window displays.

4 Choose Opt_w_subckt as the Data Source Name and click OK.

5 Repeat steps 3 and 4 for the lpf:DB(|S[2,1]) measurement. The modified measurements are shown as follows.

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6 Choose Simulate > Analyze. The simulation response displays on the graph.

7 Open the Opt_w_subckt schematic. Select the X=Xvector[1] equation, right-click, and choose Properties. The Edit Equation window displays.

100 300 500 700 900 1000Frequency (MHz)

subckt opt

-60

-50

-40

-30

-20

-10

0DB(|S[1 ,1 ]|)O pt_w_subckt

DB(|S[2 ,1 ]|)O pt_w_subckt

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8 Select the Optimize and Constrained check boxes under Mode. Type �1� as the Upper bound value and �3� as the Lower bound value. Click OK.

9 Add the optimization goal for the Opt_w_subckt:DB(|S[1,1]) measurement as follows. For more details, see �Add Optimization Goals� on page 4-13.

10 Choose Simulate > Optimize. The Optimize dialog box displays.

11 Click on the arrow to the right of Optimization Methods and select Random (Local), type �100� in Maximum Iterations, and click Start. The simulation runs.

12 When the simulation is complete, click Close to exit the Optimize dialog box. View the finalized optimized response in the schematic and on the graph, as follows.

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This concludes the linear simulation example. You can save your work if you wish by choosing File > Save Project.

100 300 500 700 900 1000Frequency (MHz)

subckt opt

-60

-50

-40

-30

-20

-10

0DB(|S[1 ,1 ]|)O pt_w_subckt

DB(|S[2 ,1 ]|)O pt_w_subckt

1 2

SUBCKT

NET=ID=

X S1 PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

Xvector={"lpf3","lpf2","lpf"}

X=Xvector[3]

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CREATING LAYOUTS FROM SCHEMATICS 5

Layouts are views of the physical representations of a schematic. Layout is a critical part of high-frequency circuit design and simulation, since the response of a circuit is dependent on the geometric shapes with which it is composed.

LAYOUTS IN MICROWAVE OFFICE

Microwave Office�s layout capability, architected using advanced object-oriented programming techniques, is tightly integrated with its schematic and EM structure building capabilities. The layout view is actually another view of the schematic, and any modifications you make to a schematic are automatically and instantly updated in its corresponding layout. This eliminates the need for complicated design synchronization and back annotation before you perform your simulations.

The following example is used to demonstrate the more basic layout features. Microwave Office offers many advanced features that allow you to generate complex layouts such as MMIC circuits and various types of multi-layer boards. For more advanced layout topics, refer to the Microwave Office User Guide.

Layout Tips and TricksKeep in mind the following tips as you use Microwave Office�s layout capability.

Keystrokes Layout Function

Press the + key Zoom in

Press the - key Zoom out

Press the Home key Full view

Press the Ctrl key, select a shape, move the mouse

Snap to corners, edges, and centers of circles

Select a shape, hold down the mouse button, press the Tab key

Move shape with coordinate entry

Press Ctrl+Shift while clicking on layered shapes

Cycle through layered shapes/elements and select them individually

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CREATING A LAYOUT FROM A SCHEMATIC

This example demonstrates how to use Microwave Office to create a layout from a schematic. It includes the following main steps:

� Importing a Layer Process File (LPF)

� Editing Database Units and Default Grid Size

� Importing a cell library

� Importing and placing a data file in a schematic

� Changing a schematic symbol

� Placing microstrip lines for layout

� Assigning an artwork cell to a schematic element

� Viewing a layout

� Creating an artwork cell

� Anchoring a layout cell

� Manipulating the MTRACE element in layout

� Snapping functions in layout

� Exporting layout

CREATE A NEW PROJECT

To create a new project:

1 Choose File > New Project.

2 Choose File > Save Project As. The Save As dialog box displays.

3 Type a project name (for example, �layout_example�), and click Save.

IMPORT A LAYER PROCESS FILE

A Layer Process File (LPF) defines the default settings for the layout view, including drawing layers, layer mappings, 3D views, and EMsight mappings.

To import an LPF:

1 Click the Layout tab at the lower left of the window to display the Layout Manager.

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2 Right-click Layer Setup in the Layout Manager, and choose Import Process Definition. The Open dialog box displays.

3 Locate the C:\Program Files\AWR\AWR2002 directory and double-click on it to open it. (This is the default directory in which Microwave Office is installed. If you changed the default install directory, then locate that directory instead.)

4 Click on the MIC_English.lpf file and click Open. The lower pane of the Layout Manager looks like the following figure.

EDITING DATABASE UNITS AND DEFAULT GRID SIZE

A database unit is defined as the smallest unit of precision for a layout. It is very important that this parameter is not changed once it has been set. Changing database units can cause rounding errors that may lead to problems in the layout file. The grid size is important because many IC designs must reside on a grid. The grid must be greater than or equal to the database unit. Because the grid multipliers smallest unit is .1x, it is recommended that the grid be set to 10 times the database unit. This prevents having a smaller grid than database unit.

To edit the database unit and grid size:

1 Choose Options > Layout Options.

Layout Manager

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2 Type �.1� in Grid Spacing and �.01� in Database unit size, and then click OK.

IMPORT A GDSII CELL LIBRARY

Cell libraries are used within Microwave Office to provide both the physical packages and footprints for printed circuit board or hybrid design processes, as well as the standard artwork cells used in MMIC and RFIC design processes. Microwave Office supports the GDSII file format as the native format for the drawing tool.

To import a GDSII cell library:

1 Right-click Cell Libraries in the Layout Manager, and choose Read GDSII Library.

2 Locate the C:\Program Files\AWR\AWR2002 directory, and double-click on it to open it. (This is the default directory in which Microwave Office is installed. If you changed the default install directory, then locate that directory instead.)

3 Double-click the Examples subdirectory, then double-click on the Quick Start subdirectory.

4 Click the packages.gds file and click Open. The imported cell library displays in the Layout Manager. If a warning message displays, click OK.

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IMPORT A DATA FILE

To import a data file:

1 Click the Proj tab in the lower left window.

2 Right-click Data Files in the Project Browser, and choose Import Data File. The Open dialog box displays.

3 Locate the C:\Program Files\AWR\AWR2002 directory and double-click on it to open it. (This is the default directory in which Microwave Office is installed. If you changed the default install directory, then locate that directory instead.)

4 Double-click the Examples subdirectory, then double-click on the Quick Start subdirectory.

5 Click the N76038a.s2p file and then click Open.

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PLACE A DATA FILE IN A SCHEMATIC

To place a data file in a schematic:

1 Right-click Circuit Schematics in the Project Browser, and choose New Schematic. The Create New Schematic dialog box displays.

2 Type �qs layout�, and click OK.

3 Click the Elem tab in the lower left window to display the Element Browser.

4 Click the scroll arrows to locate Subcircuits, and click on it. The subcircuit models display in the lower pane.

5 Click on the N76038a model, and holding the mouse button down, drag the element into the schematic window, release the mouse button, position the element, and click to place it, as follows.

CHANGE THE GROUND NODE OF A DATA FILE

You may occasionally need to change the ground node because you can only associate artwork cells with an element that has the same number of nodes.

To expose the ground node of a transistor data file:

1 Double-click the subcircuit element in the schematic window. The Element Options dialog box displays.

2 Click the Ground tab.

3 Select Explicit ground node, and click OK.

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CHANGE THE ELEMENT SYMBOL

The subcircuit symbol can be changed to represent a FET so that you can see which nodes correspond to the gate, drain, and source.

To change the symbol:

1 Double-click the subcircuit element in the schematic window. The Element Options dialog box displays.

2 Click the Symbol tab.

3 Select [email protected] in the list box, and then click OK.

PLACE MICROSTRIP ELEMENTS FOR LAYOUT

Microstrip elements have default layout cells that are associated with each element. The layout cells are parameterized and dynamically sized to the values specified for each parameter.

Microwave Office has specialized microstrip elements called Icells� (for intelligent cells) that do not require any parameter values for the dimensions of the element. Icells automatically inherit the necessary parameters from the connecting element.

To place microstrip elements:

1 Click the Elem tab at the lower left of the window to display the Element Browser.

2 Double-click on Microstrip in the Element Browser.

3 Click on Lines to display the line models in the lower pane.

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4 Click the MLIN model, and holding the mouse button down, drag the element into the schematic window, release the mouse button, position the element onto node 1 of the N7068a subcircuit, and click to place it.

5 Now click on Junctions under Microstrip in the Element Browser. The junction models display in the lower pane.

HINT: Elements displaying a �$� on the end of the element name inherit their attributes from the ports to which they connect. Elements displaying an �X� on the end of the element name are created from a look-up table of EM generated models. Thus, the name �MTEEX$� is a microstrip tee junction based on an EM model look-up table that inherits its widths from the ports to which it connects.

6 Click on the MTEE$ model, and holding the mouse button down, drag the element into the schematic window, release the mouse button, position the element to connect to the MLIN element as follows, and click to place it.

7 Click on Lines under Microstrip. Click the MTRACE model in the lower window, and holding the mouse button down, drag the element into the schematic window, release the mouse button, position the element onto node 1 of the MTEE$ element, and click to place it.

8 Click the MLEF model in the lower window, and holding the mouse button down, drag the element into the schematic window, release the mouse

MLIN

L=W=

ID=

400 mil50 milTL1

1

2

3

SUBCKT

NET=ID=

N76038a S1

MLIN

L=W=ID=

400 mil50 milTL1

1 2

3

MTEE$ID=TL2

1

2

3

SUBCKT

NET=ID=

N76038a S1

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button, right-click three times to rotate the element, position it onto node 3 of the MTEE$ element, and click to place it.

9 Double-click the MTRACE element in the schematic window to display the Element Options dialog box.

10 Edit the MTRACE parameters to match what is shown in the following figure, then click OK.

11 Repeat step 9 for the MLIN and MLEF elements to edit their parameters to match what is shown in the figure.

12 Click on Substrates in the Element Browser. The substrate models display in the lower pane.

13 Click on the MSUB model, and holding the mouse button down, drag the element into the schematic window, release the mouse button, position the element as shown in the figure below, and click to place it.

14 Double-click the MSUB element in the schematic window to display the Edit Element dialog box. Edit the MSUB parameters to match what is shown in the following figure. Click OK.

MLIN

L=W=

ID=

100 mil10 milTL1

1 2

3

MTEE$ID=TL2

MTRACE

M=BType=

L=W=

ID=

0.6 2 200 mil10 milX1

MLEF

L=W=

ID=

150 mil20 milTL3

1

2

3

SUBCKT

NET=ID=

N76038a S1

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15 Click the Port button on the toolbar, slide the cursor into the schematic, position the port on the left node of the MTRACE element as shown in the following figure, and click again to place it.

16 Click the Port button on the toolbar again, slide the cursor into the schematic, right-click three times to rotate the port, position the port on node 2 of the SUBCKT element, and click again to place it.

17 To complete the schematic, click and release the Ground button on the toolbar, slide the cursor into the schematic, position the ground on node 3 of the SUBCKT element, and click again to place it.

MLIN

L=W=

ID=

100 mil10 milTL1

1 2

3

MTEE$ID=TL2

MTRACE

M=BType=

L=W=

ID=

0.6 2 200 mil10 milX1

MLEF

L=W=

ID=

150 mil20 milTL3

MSUB

Name=ErNom=Tand=Rho=

T=H=

Er=

SUB1 9.8 0 1 .1 mil10 mil9.8

1

2

3

SUBCKT

NET=ID=

N76038a S1

MLIN

L=W=ID=

100 mil10 milTL1

1 2

3

MTEE$ID=TL2

MTRACE

M=BType=

L=W=ID=

0.6 2 200 mil10 milX1

MLEF

L=W=ID=

150 mil20 milTL3

MSUB

Name=ErNom=Tand=Rho=T=H=Er=

SUB1 9.8 0 1 .1 mil10 mil9.8

1

2

3

SUBCKT

NET=ID=

N76038a S1

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

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ASSIGN AN ARTWORK CELL TO A SCHEMATIC ELEMENT

Artwork cells that represent a package layout can be assigned to a schematic element. To assign an artwork cell:

1 Double-click the N76038a subcircuit element in the schematic window to display the Element Options dialog box.

2 Click the Layout tab.

3 Select Alpha_212_3 in Compatible cells, and click OK.

VIEW A LAYOUT

The schematic and layout are different views of the same database. Any edits to the parameters in the schematic are instantly updated in the layout, and vice versa

To view a layout:

1 Click on the schematic window to make it active.

2 Choose Schematic > View Layout. The layout displays in a layout window.

3 Choose Edit > Select All to select all of the layout cells.

4 Choose Edit > Snap Together to snap all of the faces of the artwork cells together.

HINT: Click the View Layout button on the toolbar to view a layout representation.

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ANCHORING A LAYOUT CELL

Layout cells have various properties that determine the connectivity of each cell in the layout view. One of the important properties is anchoring. Anchoring a layout cell holds the cell in place so that it cannot be moved by snapping functions. An anchored layout cell is typically used to define a reference point for the layout.

To anchor a layout cell:

1 Select the assigned artwork cell Alpha_212_3. Right-click, and choose Shape Properties to display the Cell Options dialog box.

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2 Click the Layout tab, select the Use for anchor check box, and click OK. The artwork cell now has an anchor symbol as follows.

CREATE AN ARTWORK CELL

To create an artwork cell:

1 Click the Set Grid Snap Multiple button on the toolbar and set it to 10x.

2 Click the Layout tab to activate the Layout Manager.

3 Right-click on Packages, and choose New Layout Cell. The Create New Layout Cell dialog box displays.

4 Name the cell �chip cap� and click OK. A drawing window displays in the workspace.

5 Click the copper box in the left column of the lower pane to enable copper as the active layer, as shown in the following figure. (Do not click the light-bulb, as that specifies hiding or showing layers.)

6 Choose Layout > Rectangle.

Click this box to enable copper as the active layer.

Click light bulb to toggle the view of drawing layers.

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7 Slide the cursor into the drawing window, then press the Tab key. The Enter Coordinates dialog box displays.

8 Type the values �0� and �10� in x and y, respectively, and click OK.

9 Press the Tab key again to display the Enter Coordinates dialog box.

10 Type the values �10� and �-10� in dx and dy, respectively, and click OK. The resulting drawing is shown in the following figure.

11 Click the Footprint box in the left column of the lower pane of the Layout Manager to enable footprint as the active layer.

12 Click on the drawing window to make it active.

13 Choose Layout > Rectangle.

14 Slide the cursor into the drawing window, then press the Tab key. The Enter Coordinates dialog box displays.

15 Type the values �10� and �10� in x and y, respectively, and click OK.

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16 Press the Tab key again to display the Enter Coordinates dialog box.

17 Type the values �20� and �-10� in dx and dy, respectively, and click OK. The resulting drawing is shown in the following figure.

18 Click on the copper square in the drawing window, and press Ctrl+C then Ctrl+V to copy and paste it. Slide the mouse to position the copied square along the right edge of the rectangle, and click to place it.

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Creating a Layout From a Schematic5

ADD PORTS TO AN ARTWORK CELL

Ports in the artwork cell editor define the faces to which other layout cells connect. The orientation of the port arrow determines the direction of connection to the adjacent layout cell.

To add ports to an artwork cell:

1 Choose Layout > Cell Port.

2 Slide the cursor into the drawing window, and press and hold the Ctrl key while you move the cursor over the bottom left vertex of the square until a square symbol displays on the vertex. Do not release the Ctrl key.

3 With the Ctrl key still pressed, click and hold the mouse button down while you slide the cursor to the top vertex until another square displays on that vertex. Release the mouse button, and lift the Ctrl key.

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4 Repeat steps 1 through 3 to place a port on the opposite side of the drawing, but start at the top vertex and draw down.

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5 Click on the X at the top right of the chip cap window. A dialog box asks if you want to save the cell edits. Click Yes to save.

EDIT THE SCHEMATIC AND ASSIGN A CHIP CAP CELL

To edit the schematic and assign a chip cap cell:

1 Click on PORT 1 in the schematic window.

2 Press and hold the Ctrl key, and click and hold the mouse button while you drag the port away from the MTRACE element, as shown in the following figure.

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3 Click the Elem tab in the lower left window to display the Element Browser.

4 Double-click on Lumped Element, then click on Capacitor to display capacitor models in the lower pane.

5 Click the CAP model, and holding the mouse button down, drag the element into the schematic window, release the mouse button, position the element between PORT 1 and the MTRACE element, and click to place it.

6 Double-click the CAP C1 element in the schematic window. The Element Options dialog box displays.

7 Click the Layout tab.

8 Select chip cap in Compatible cells, and click OK.

9 Choose Schematic > View Layout. The new layout displays in the workspace. The layout and corresponding schematic are shown as follows.

MLIN

L=W=ID=

100 mil10 milTL1

1 2

3

MTEE$ID=TL2

MTRACE

M=BType=

L=W=ID=

0.6 2 200 mil10 milX1

MLEF

L=W=ID=

150 mil20 milTL3

MSUB

Name=ErNom=Tand=Rho=T=H=Er=

SUB1 9.8 0 1 .1 mil10 mil9.8

1

2

3

SUBCKT

NET=ID=

N76038a S1

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

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ROUTE THE MTRACE ELEMENT IN LAYOUT

The MTRACE element is a special element that can be edited in the layout view to route a microstrip line.

To route the MTRACE element:

1 Double-click the MTRACE element in the Layout View to activate the blue grab diamonds, as shown in the following figure.

2 Slide the mouse cursor over the right-most diamond until a double arrow symbol displays. Double-click to activate the routing tool.

3 Move the routing tool to the desired point and click to place. (Right-click the mouse to delete the last point; press the Esc key to cancel the activity.)

MLIN

L=W=ID=

100 mil10 milTL1

1 2

3

MTEE$ID=TL2

MTRACE

M=BType=

L=W=ID=

0.6 2 200 mil10 milX1

MLEF

L=W=ID=

150 mil20 milTL3

MSUB

Name=ErNom=Tand=Rho=T=H=Er=

SUB1 9.8 0 1 .1 mil10 mil9.8

CAP

C=ID=

1 pFC1

1

2

3

SUBCKT

NET=ID=

N76038a S1

PORT

Z=P=50 Ohm1

PORT

Z=P=50 Ohm2

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4 Continue to route points by sliding the routing tool and clicking to place, then double-click to complete the routing.

Figure 5-1. Activate the grab diamonds and activate cursor

Figure 5-2. Place the routing tool

Figure 5-3. Specify routing points

HINT: The MLIN element is a straight element and you can change its width in the layout. You can edit the MTRACE elements in the layout to create jogs and bends and chamfered corners. You can edit the MCTRACE element to create jogs and bends with rounded corners.

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SNAPPING FUNCTIONS FOR LAYOUT CELLS

Snapping functions connect the faces of artwork cells in various configurations. Microwave Office 2002 has new snapping options that you can set from the Layout Options dialog box.

To specify the snapping options:

1 Choose Options > Layout Options. The Layout Options dialog box displays.

2 Select Manual snap selected objects only in Layout Cell Snap Options. Click OK.

To move the layout cells away from each other so that the change in snapping options can be viewed,

3 Click the MLEF layout cell, and holding the mouse button down, drag it to a new position as follows. Click to place it.

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4 Repeat step 3 with the MTRACE element and the chip cap cell. Position the layout cells as follows.

The red lines indicate that the faces of the layout cells are not snapped together. To snap a selected set of layout cells together,

5 Hold down the Shift key, and select the MLEF, MTRACE, and MTEE$ layout cells in the layout window.

6 Click the Snap Together button on the toolbar. Observe that the chip cap layout cell and MLIN layout cell are not snapped together.

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To snap all of the faces together:

7 Type Ctrl+A on the keyboard to select all of the layout cells.

8 Click the Snap Together button on the toolbar. The layout is shown as follows.

The �snap to fit� function finishes the routing of an MTRACE layout cell to a specified adjacent layout cell. In this example, the chip cap layout cell will be moved and the MTRACE will re-route to snap to the chip cap face.

To snap to fit the MTRACE to the chip cap:

9 Position the chip cap artwork cell as follows.

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10 Select the MTRACE layout cell, hold down the Shift key and select the chip cap artwork cell.

11 Click the Snap to Fit button on the toolbar. The MTRACE will route to snap to the chip cap artwork cell as follows.

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EXPORT THE LAYOUT

To export a layout:

1 Choose Options > Drawing Layers to specify the file layers to be exported. The Layer Setup dialog box displays.

2 Click the Export Mapping tab.

3 Click the DXF tab at the bottom of the dialog box, deselect all of the drawing layers except the copper layer in Write Layers, and click OK.

4 Choose Layout > Export Layout. The Save As dialog box displays.

5 Select DXF(Flat*.dxf) in Save As Type.

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6 Type �myfile� as the Filename, and click Save to export the copper file layer to a DXF file.

This concludes the layout simulation example. You can save your work by choosing File > Save Project.

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .USING THE NONLINEAR SIMULATOR 6

Nonlinear simulations use harmonic balance or Volterra series sources to excite a circuit. Harmonic balance and Volterra series analysis are not interchangeable solutions to a nonlinear circuit. Harmonic balance analysis is best used for nonlinear circuits such as power amplifiers, mixers, and multipliers. Volterra series analysis, which is a linear pertubation method, is best used for weakly nonlinear circuits like amplifiers operating below the 1db compression point. This chapter introduces harmonic balance simulations only; for more information on Volterra series analysis, see the Microwave Office User Guide.

HARMONIC BALANCE IN MICROWAVE OFFICE

In Microwave Office, harmonic balance simulations are easily constructed. The schematic entry, measurements, and analysis are accomplished much as they are for a linear simulation. The major difference between the setup for harmonic balance nonlinear versus linear analysis is that harmonic balance simulation measures the port excitation of the circuit. This requires the addition of a port that specifies power and frequency, as well as the option to sweep either or both of these parameters. The Microwave Office harmonic balance simulator allows you to specify single and multiple excitation ports to perform single- and multi-tone analysis. Whenever a harmonic balance source is specified in a schematic, the harmonic balance simulator is automatically invoked when you perform a simulation.

Single-Tone AnalysisA single-tone harmonic balance analysis involves simulating the circuit at a fundamental frequency, at integer multiples of the fundamental frequency and at DC. Single-tone harmonic balance requires that you specify the fundamental frequency and the total number of harmonics.

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Multi-Tone AnalysisTwo-tone and three-tone harmonic balance simulation is used to determine the output of a circuit with excitations at different fundamental frequencies. Two-tone harmonic balance analysis is fitting for circuits such as mixers, where one tone is used to model the local oscillator and the second tone is used for an RF input. Three-tone harmonic balance analysis can be used to measure mixer intermodulation distortion, whereby two tones are used for the RF signals and the third tone is used as a local oscillator to drive the mixer. Three-tone analysis is not covered in this chapter; refer to the Microwave Office User Guide for more information.

Nonlinear MeasurementsMicrowave Office allows you to create nonlinear measurements in both the frequency and time domain. It offers a complete set of nonlinear measurements that include, large signal S-parameters, power, voltage, and current. Because harmonic balance simulation is capable of solving for both swept power and frequency at every harmonic, indexes are used to hold swept parameters constant. The Add Measurement dialog box shows the specific value of each index.

The following example illustrates some of the key features of the Microwave Office nonlinear simulator.

HOW TO CREATE A POWER AMPLIFIER CIRCUIT

This example demonstrates how to use Microwave Office to simulate a power amplifier circuit using the harmonic balance nonlinear simulator. It includes the following main steps:

� Using nonlinear models from the element library

� Creating an IV curve measurement

� Biasing the transistor and measuring voltages and currents

� Adding harmonic balance ports to a circuit

� Creating a hierarchical circuit using subcircuits

� Creating a power out versus frequency measurement

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� Creating a dynamic load line measurement

� Adding a two-tone harmonic balance port

CREATE A NEW PROJECT

To create a new project:

1 Choose File > New Project.

2 Choose File > Save Project As. The Save As dialog box displays.

3 Type a project name (for example, �nonlinear_example�), and click Save.

SET DEFAULT PROJECT UNITS

To set default project units:

1 Choose Options > Project Options. The Project Options dialog box displays.

2 Click the Global Units tab.

3 Modify the units by clicking the arrows to the right of the scroll boxes so that they match those in the following figure, and click OK.

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CREATE A SCHEMATIC

To create a schematic:

1 Choose Project > Add Schematic > New Schematic. The Create New Schematic dialog box displays.

2 Type �IV Curve�, and click OK. A schematic window displays in the workspace.

PLACE A NONLINEAR MODEL FROM THE LIBRARY

To place a nonlinear model:

1 Click the Elem tab at the lower left of the window to display the Element Browser.

2 Scroll through the Element Browser, and double-click Library to expand it.

3 Double-click on Nonlinear under Library to expand it.

4 Click on GettingStarted under Nonlinear.

5 Click on GBJT under GettingStarted. A model displays in the lower pane.

6 Click the BLT11_chip model, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the element as shown in the following figure, and click to place it.

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PLACE AN IV CURVE METER ON THE NONLINEAR ELEMENT

To place an IV curve meter element with stepped current:

1 Scroll through the Element Browser, and double-click on MeasDevices to expand it. Click IV to display its meter models in the lower pane.

2 Click on the IVCURVEI model, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the element as shown in the following figure, and click to place it.

3 Place the cursor over the Step node of IVCURVEI. The cursor displays as a wire coil symbol. Click, then drag the cursor to node 1 of the GBJT transistor, and click to place the wire.

4 Repeat step 3 to connect the Swp node of IVCURVEI to node 2 of the GBJT transistor.

5 Click the Ground button on the toolbar. Move the cursor into the schematic window, position the ground on node 3 of the GBJT transistor, and click to place it.

EDIT THE IV CURVE METER ELEMENT

To specify IVCURVEI settings:

1 Double-click IVCURVEI in the schematic window. The Element Options dialog box displays.

2 In the Value column, change the values to those in the following figure and click OK.

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ADD AN IV CURVE MEASUREMENT

To create a graph and add an IV curve measurement:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Right-click on Graphs and choose Add Graph. The Create Graph dialog box displays.

3 Type �IV BJT� in Graph Name, select Rectangular as the Graph Type, and click OK. The graph displays in the workspace.

4 Right-click on IV BJT under Graphs in the Project Browser, and choose Add Measurement. The Add Measurement dialog box displays.

5 Select Nonlinear Current in Meas. Type and IV Curve in Measurement. Select IV Curve as the Data Source Name, and click OK.

6 Choose Simulate > Analyze. The simulation response shown in the following figure displays on the graph.

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CREATE A BIAS CIRCUIT

To create a DC bias circuit:

1 Choose Project > Add Schematic > New Schematic. The Create New Schematic dialog box displays. Type �DC Bias� and click OK. A schematic window displays in the workspace.

2 Click the Elem tab in the lower left window to display the Element Browser.

3 Scroll through the Element Browser and double-click on Library to expand it. Double-click on Nonlinear to expand it, then click on GettingStarted and then GBJT. A model displays in the lower pane. Click on the BLT11_chip model, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the element, and click to place it.

4 Double-click on Lumped Element in the Element Browser to expand it, then click on Inductor. A set of inductor models display in the lower pane. Click on the IND model, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the element a distance above the GBJT transistor as shown in the following figure, and click to place it.

5 Place the cursor on node 1 of the GBJT transistor. The cursor displays as a wire coil symbol. Click, then drag the cursor to the right node of IND, and click to place the wire.

0 5 10 15Voltage (V)

IV BJT

-400

0

400

800

1200

IVCurve (mA)IV curve

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6 Double-click the IND graphic in the schematic window. The Element Options dialog box displays. Enter �1� as the Value for Inductance (L), and click OK.

7 In the Element Browser, click on Resistor under Lumped Element. A set of resistor models display in the lower pane. Click on the RES model, and holding the mouse button down, drag it into the schematic window, release the mouse button, right-click to rotate the element, position it onto node 3 of the GBJT transistor as shown in the following figure, and click to place it.

8 Double-click on RES (the graphic, not the parameters) in the schematic window. The Element Options dialog box displays. Enter �0.5� as the Value for Resistance (R), and click OK.

9 Click the Ground button on the toolbar. Move the cursor into the schematic window, position the ground on the bottom of RES R1 as shown in the previous figure, and click to place it.

10 In the Element Browser, double-click on Sources to expand it, then click on DC. A set of source models display in the lower pane. Click on the DCVS

S

C

B

E

1

2

3

4

GBJTID=GP_BLT11_chip_1

RES

R=ID=

.5 OhmR1

DCVS

V=ID=

1 VV1

DCVS

V=ID=

6 VV2

IND

L=ID=

1 uHL1

IND

L=ID=

1 uHL2

I_METERID=AMP1

V_METERID=VM1

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model and drag it into the schematic window, release the mouse button, position the element onto the open node of IND L1 as shown in the previous figure, and click to place it.

11 Click the Ground button on the toolbar. Move the cursor into the schematic window, position the ground on the open end of DCVS V1 as shown in the previous figure, and click to place it.

12 Double-click the DCVS element graphic in the schematic window. The Element Options dialog box displays. Enter �1� as the Value for DC Voltage (V), and click OK.

13 In the Element Browser, click on MeasDevice. A set of meter models displays in the lower pane. Click on the I_METER model, and holding the mouse button down, drag it into the schematic window, release the mouse button, right-click three times to rotate it, position the element onto node 2 of the GBJT transistor as shown in the previous figure, and click to place it.

14 Next click the V_METER model, and place it to the right of the GBJT transistor as shown in the previous figure.

15 Place the cursor on the negative terminal of the VMETER element. The cursor displays as a wire coil symbol. Click, then drag the cursor to the ground, and click to place the wire. Follow these same steps to connect a wire between the positive terminal of VMETER and node 2 of the GBJT transistor.

16 Click on IND L1 in the schematic window. Press Ctrl+C, then Ctrl+V to copy and paste it. Slide the cursor to position the new IND element on the open node of I_METER as shown in the previous figure, and click to place it.

17 Click on DCVS in the schematic window. Press Ctrl+C, then Ctrl+V to copy and paste it. Slide the cursor to position the new DCVS element on the open node of IND L2 as shown in the previous figure, and click to place it.

18 Double-click on DCVS in the schematic window. The Element Options dialog box displays. Enter �6� as the Value for DC Voltage (V), and click OK.

19 Click the Ground button on the toolbar. Move the cursor into the schematic window, position the ground on the negative node of DCVS V2 as shown in the previous figure, and click to place it.

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ADD A DC VOLTAGE AND CURRENT MEASUREMENT

To create a tabular graph and add a DC voltage and current measurement:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Right-click on Graphs and choose Add Graph. The Create Graph dialog box displays.

3 Type �DC Bias� as the Graph Name, select Tabular as the Graph Type, and click OK. The graph displays in the workspace.

4 Right-click on DC BIAS under Graphs, and choose Add Measurement. The Add Measurement dialog box displays.

5 Select Nonlinear Current in Meas. Type and select Icomp in Measurement. Select DC Bias as the Data Source Name and select I_METER.AMP1 as the Measurement Component.

6 Click on the arrows to the right to select 0 in Harmonic Index and 1 in Power Swp Index, then click Add.

7 Now, select Nonlinear Voltage in Meas. Type, select Vcomp as the Measurement, select DC Bias as the Data Source Name, and V_METER.VM1 as the Measurement Component.

8 Click on the arrows to the right to select 0 in Harmonic Index and 1 in Power Swp Index, then click Add and Close.

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9 Choose Simulate > Analyze. The tabulated DC data shown in the following figure displays on the graph.

ADD A HARMONIC BALANCE PORT

Before adding the harmonic balance port, you must add DC blocking capacitors to the input and output of the transistor. To add DC blocking capacitors:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Click the + symbol to the left of Circuit Schematics to expand it.

3 Double-click on DC Bias under Circuit Schematics. The DC Bias schematic window displays in the workspace.

4 Click the Elem tab in the lower left window to display the Element Browser.

5 Double-click Lumped Element in the Element Browser to expand it, then click on Capacitor. A set of capacitor models display in the lower pane. Click on the CAP model, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the element onto node 1 of the GBJT transistor as shown in the following figure, and click to place it.

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6 Double-click on CAP in the schematic window. The Element Options dialog box displays. Enter �100� as the Value for Capacitance (C), and click OK.

7 Click on CAP (hereinafter referred to as CAP C1) in the schematic window. Press Ctrl+C, then Ctrl+V to copy and paste it. Move the cursor to position the new CAP element (CAP C2) to the right of the circuit as shown in the following figure, and click to place it.

8 Place the cursor on the left node of CAP C2. The cursor displays as a wire coil symbol. Click, then drag the cursor to the node of I_METER that is connected to IND L2, and click to place the wire.

An RF bypass capacitor must also be added across the emitter resistor. To add an RF bypass capacitor:

9 Click on CAP C1 in the schematic window. Press Ctrl+C, then Ctrl+V to copy and paste it. Move the cursor to position the new CAP element (CAP C3) to the left of RES R1 as shown in the following figure, right-click to rotate it, and click to place it.

10 Place the cursor on the top node of CAP C3. The cursor displays as a wire coil symbol. Click, then drag the cursor to node 3 of the GBJT transistor, and click to place the wire. Follow these same steps to connect a wire between the bottom node of CAP C3 and ground.

S

C

B

E

1

2

3

4

GBJTID=GP_BLT11_chip_1

RES

R=ID=

.5 OhmR1

DCVS

V=ID=

1 VV1

DCVS

V=ID=

6 VV2

IND

L=ID=

1 uHL1

IND

L=ID=

1 uHL2

I_METERID=AMP1

V_METERID=VM1

CAP

C=ID=

100 pFC1

CAP

C=ID=

100 pFC2

CAP

C=ID=

100 pFC3

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To add a harmonic balance port:

1 Double-click on Ports in the Element Browser to expand it, then click Harmonic Balance. A set of port models display in the lower pane. Click on the PORT1 model, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the element onto the open node of CAP C1 (input blocking) as shown in the following figure, and click to place it.

2 Double-click on PORT1 in the schematic window. The Element Options dialog box displays. Enter �23� as the Value of Power (PWR), and click OK.

3 Click the Port button on the toolbar. Move the cursor into the schematic window, right-click twice to rotate the port, position it on the open node of CAP C2 (output blocking) as shown in the following figure, and click to place it. This port is considered a termination port.

SPECIFY NONLINEAR SIMULATION FREQUENCIES

Nonlinear frequencies can be specified independently of the project frequencies. To specify nonlinear frequencies:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Click the + symbol to the left of Circuit Schematics to expand it.

S

C

B

E

1

2

3

4

GBJTID=GP_BLT11_chip_1

RES

R=ID=

.5 OhmR1

DCVS

V=ID=

1 VV1

DCVS

V=ID=

6 VV2

IND

L=ID=

1 uHL1

IND

L=ID=

1 uHL2

I_METERID=AMP1

V_METERID=VM1

CAP

C=ID=

100 pFC1

CAP

C=ID=

100 pFC2

CAP

C=ID=

100 pFC3

PORT1

Pwr=Z=P=

23 dBm50 Ohm1

PORT

Z=P=

50 Ohm2

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3 Right-click on DC Bias and choose Options. The Options dialog box displays.

4 Click the Nonlinear Frequencies tab.

5 Deselect Use Project Frequency.

6 Select GHz as the Data Entry Units, type �1.5� in Start, type �2.5� in Stop, type �0.2� in Step, select Replace, and click Apply. The frequency points display in Current Range.

7 Click OK.

ADD A LARGE SIGNAL GAMMA MEASUREMENT

Large signal gamma can be defined as the large signal s11. Large signal S-parameters are a general form of large signal gamma. For example, a large signal S-parameter can be defined for s21 for harmonic 1 at port 2, and harmonic 2 at port 1.

To create a Smith Chart:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Right-click on Graphs, and choose Add Graph. The Create Graph dialog box displays.

3 Type �Input reflection� in Graph Name, select Smith Chart as the Graph Type, and click OK. The graph displays in the workspace.

To add a Large Signal GAMMA measurement:

4 Right-click Input reflection under Graphs in the Project Browser and choose Add Measurement. The Add Measurement dialog box displays.

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5 Select Nonlinear Parameters as the Meas. Type and select Gcomp as the Measurement. Select DC Bias as the Data Source Name, select PORT_1 as the Measurement Component, click on the arrows to the right to select 1 in both Harmonic Index and Power Swp Index, and then click Add and Close.

6 Choose Simulate > Analyze. The following simulation response displays on the Smith Chart.

0 1.0

1.0

-1.

0

10.0

10.0

-10.0

5.0

5.0

-5.0

2.0

2.0

-2.0

3.0

3.0

-3.0

4.0

4.0

-4.0

0.2

0.2

-0.2

0.4

0.4

-0.4

0.6

0.6

-0.6

0.8

0.8

-0.8

Input ReflectionSwp Max

2.5GHz

Swp Min1.5GHz

Gcomp[PORT_1,1,1]DC bias

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IMPORT SCHEMATICS

The input and output matching for the amplifier are imported from schematics that have already been created. To import the input match schematic:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Right-click on Circuit Schematics in the Project Browser, and choose Import Schematic. The Open dialog box displays.

3 Locate the C:\Program Files\AWR\AWR2002 directory and double-click on it to open it.

4 Double-click the Examples subdirectory, and then double-click the Quick Start subdirectory.

5 Select the input match.sch file and click Open to open the schematic as follows.

TLIN

F0=EL=Z0=ID=

1.9 GHz83 Deg10 OhmTL1

TLIN

F0=EL=Z0=ID=

1.9 GHz25 Deg78 Ohmind1 TLOC

F0=EL=Z0=ID=

1.9 GHz90 Deg21 OhmTL2

PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

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To import the output match schematic:

6 Right-click on Circuit Schematics in the Project Browser and choose Import Schematic. The Open dialog box displays.

7 Locate the C:\Program Files\AWR\AWR2002 directory and double-click on it to open it.

8 Double-click the Examples subdirectory, then double-click the Quick Start subdirectory.

9 Select the output match.sch file and click Open to import (and display in the workspace) the match schematic shown in the following figure.

ADDING SUBCIRCUITS TO A SCHEMATIC

Whenever an n-port schematic is created or imported it automatically becomes an n-port subcircuit. These subcircuits can be used within other schematics to create circuit hierarchy. To add the input match subcircuit to the DC Bias schematic:

1 Click the + symbol to the left of Circuit Schematics in the Project Browser to expand it.

2 Double-click on DC Bias under Circuit Schematics to display the DC Bias schematic.

3 Click on PORT1 in the schematic window. Press and hold the Shift key while you click on CAP C1 (the capacitor connected to PORT1). Both PORT1 and CAP C1 should be selected.

TLIN

F0=EL=Z0=ID=

1.9 GHz88 Deg30 Ohmquar

TLIN

F0=EL=Z0=ID=

1.9 GHz22 Deg80 Ohmind

CAP

C=ID=

100 pFC1

PORT

Z=P=

50 Ohm1

PORT

Z=P=

50 Ohm2

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4 Press the Ctrl key, click on the selected elements, and holding the mouse button down, drag them to the left of the circuit to break the connection between the CAP C1 and the transistor, as shown in the following figure.

5 Click the Elem tab in the lower left window to display the Element Browser.

6 Click on Subcircuits in the Element Browser. A set of subcircuit models displays in the lower pane.

7 Click the input match subcircuit, and holding the mouse button down, drag it into the schematic window, release the mouse button, position the subcircuit between CAP C1 and node 1 of the transistor, and click to place it.

S

C

B

E

1

2

3

4

GBJTID=GP_BLT11_chip_1

RES

R=ID=

.5 OhmR1

DCVS

V=ID=

1 VV1

DCVS

V=ID=

6 VV2

IND

L=ID=

1 uHL1

IND

L=ID=

1 uHL2

I_METERID=AMP1

V_METERID=VM1

CAP

C=ID=

100 pFC1

CAP

C=ID=

100 pFC2

CAP

C=ID=

100 pFC3

PORT1

Pwr=Z=P=

23 dBm50 Ohm1

PORT

Z=P=50 Ohm2

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8 If the subcircuit nodes do not properly connect with the capacitor and transistor, you may need to click the appropriate element, and holding the mouse button down, drag the element until the proper connections are made.

9 Click on PORT2. Press and hold the Shift key while you click on CAP C2 (the capacitor connected to PORT2). Both PORT2 and CAP C2 should be selected.

10 Press the Shift key, click on the selected elements, and holding the mouse button down, drag them to the right of the circuit to break the connection between the CAP C2 and the wire, as shown in the following figure.

S

C

B

E

1

2

3

4

GBJTID=GP_BLT11_chip_1

RES

R=ID=

.5 OhmR1

DCVS

V=ID=

1 VV1

DCVS

V=ID=

6 VV2

IND

L=ID=

1 uHL1

IND

L=ID=

1 uHL2

I_METERID=AMP1

V_METERID=VM1

CAP

C=ID=

100 pFC1

CAP

C=ID=

100 pFC2

CAP

C=ID=

100 pFC3

1 2

SUBCKT

NET=ID=

input match S1

PORT1

Pwr=Z=P=

23 dBm50 Ohm1

PORT

Z=P=50 Ohm2

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11 Click the Elem tab in the lower left window to display the Element Browser.

12 Click Subcircuits in the Element Browser to display a set of subcircuit models in the lower pane.

13 Click the output match subcircuit, and holding the mouse button down, drag it into the schematic window, release the mouse button, right-click twice to rotate the subcircuit 180 degrees, position the subcircuit to connect to the open node of CAP C2, and click to place it.

14 Place the cursor on node 2 of the output match subcircuit. The cursor displays as a wire coil symbol. Click, then drag the cursor to node 1 of I_METER, and click to place the wire.

15 Double-click the Pwr parameter value of the PORT1 element. An edit box displays over the value. Type �18� to change the value from 23 to 18 dBm, then click outside the edit box to save the change.

IND

L=ID=

1 uHL1

S

C

B

E

1

2

3

4

RES

R=ID=

0.5 OhmR1

DCVS

V=ID=

1 VV1

I_METERID=AMP1

V_METERID=VM1

IND

L=ID=

1 uHL2

DCVS

V=ID=

6 VV2

CAP

C=ID=

100 pFC1

CAP

C=ID=

100 pFC2

CAP

C=ID=

100 pFC3

PORT1

Pwr=Z=P=

23 dBm50 Ohm1 PORT

Z=P=

50 Ohm2

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CREATE A POUT VS. FREQUENCY MEASUREMENT

To create a graph and add a DC Bias (Pout versus frequency) measurement:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Right-click on Graphs, and choose Add Graph. The Create Graph dialog box displays.

3 Type �Pout� in Graph Name, select Rectangular as the Graph Type, and click OK. The graph displays in the workspace.

4 Right-click on Pout under Graphs in the Project Browser, and choose Add Measurement. The Add Measurement dialog box displays.

5 Select Nonlinear Power as the Meas. Type and select Pcomp as the Measurement. Select DC Bias for Data Source Name, select PORT_2 for Measurement Component, click on the arrows to the right to select 1 as both the Harmonic Index and Power Swp Index, select the DBm check box under Result Type, click Add, and then click Close.

S

C

B

E

1

2

3

4

GBJTID=GP_BLT11_chip_1

RES

R=ID=

.5 OhmR1

DCVS

V=ID=

1 VV1

DCVS

V=ID=

6 VV2

IND

L=ID=

1 uHL1

IND

L=ID=

1 uHL2

I_METERID=AMP1

V_METERID=VM1

CAP

C=ID=

100 pFC1

CAP

C=ID=

100 pFC2

CAP

C=ID=

100 pFC3

1 2

SUBCKT

NET=ID=

input match S1

12

SUBCKT

NET=ID=

output match S2

PORT1

Pwr=Z=P=

18 dBm50 Ohm1

PORT

Z=P=50 Ohm2

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6 Choose Simulate > Analyze. The simulation response shown in the figure below displays on the graph.

CREATE A DYNAMIC LOAD LINE MEASUREMENT

A dynamic load line measurement plots the large signal performance of the circuit superimposed on the IV curve of the device. To create a dynamic load line measurement:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Click the + symbol to expand Graphs in the Project Browser.

1.5 2 2.5Frequency (GHz)

Pout

26

27

28

29

DB(|Pcomp[PORT_2,1,1]|) (dBm)DC bias

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3 Right-click on IV BJT under Graphs, and choose Add Measurement. The Add Measurement dialog box displays.

4 Select Nonlinear Current as the Meas. Type and select IVDLL as the Measurement. Select DC Bias for Data Source Name, select V_METER.VM1 for Voltage Measure Component, select I_METER.AMP1 for Current Measure Component, click on the arrows to the right to select 1 for both the Frequency Swp Index and Power Swp Index, and then click Add and Close.

5 Choose Simulate > Analyze. The simulation response shown in the following figure displays on the graph.

0 5 10 15Voltage (V)

IV BJT

-400

0

400

800

1200

IVCurve (mA)IV curve

IVDLL[V_METER.VM1,I_METER.AMP1,1,1] (mA)DC bias

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COPYING A SCHEMATIC IN THE PROJECT BROWSER

The next step involves a two-tone simulation that is swept over power at one frequency point. It requires a new schematic of the same circuit with a different port configuration. To create the new schematic, you must make a duplicate and edit the port configurations. To duplicate the schematic:

1 In the Project Browser, click DC bias under Circuit Schematics, and holding the mouse button down, drag it to the main Circuit Schematics entry, and release the mouse button. A duplicate schematic named Copy of DC bias is created.

2 Right-click the Copy of DC Bias schematic, and choose Rename Schematic. Rename the schematic to �Two Tone Amp� in the Rename Data Source dialog box, and then click OK.

ADDING A TWO-TONE HARMONIC BALANCE PORT

A common measurement used to characterize power amplifiers is a third order intermodulation product versus swept power. To make this measurement, two closely-spaced tones must be injected into the input port. To add a two-tone harmonic balance port:

1 Click the Two Tone Amp schematic window in the workspace to make it active.

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2 Double-click on PORT1 in the schematic window. The Element Options dialog box displays.

3 Click the Port tab.

4 In Tone Type select Tone 1 & 2, select Harmonic Balance as the Simulator Type, select Swept Power, and select Excite Fundamental Frequency under Source Excitation.

5 Click the Parameters tab and change the Values to the following, then click OK.

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ADDING A THIRD ORDER INTERMODULATION MEASUREMENT

To add a third order intermodulation product measurement:

1 Click the Proj tab in the lower left window to display the Project Browser.

2 Right-click on Graphs and choose Add Graph. The Create Graph dialog box displays.

3 Type �IM3� in Graph Name, select Rectangular as the Graph Type, and click OK. The graph displays in the workspace.

4 Right-click on IM3 under Graphs, and choose Add Measurement. The Add Measurement dialog box displays.

5 Select Nonlinear Power as the Meas. Type, and select IM1_SP as the Measurement. Select Two Tone Amp as the Data Source Name, select PORT_2 as the Measurement Component, click on the arrows to the right to select 1 for Frequency Swp Index, and then click Add.

6 Change the Measurement to IM3_SP, click Add, and then click Close.

7 Choose Simulate > Analyze. View the final simulation response on the graph, as follows.

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USING THE SWEPT VARIABLE WIZARD TO MEASURE IP3 VS VOLTAGE

An IP3 measurement does not require a swept power on the input. To speed up the swept variable simulation, a new schematic without swept power is desired. To create a new schematic for the IP3 measurement:

1 Click Two Tone Amp under Circuit Schematics in the Project Browser, and holding the mouse button down, drag it to the main Circuit Schematics entry and release the mouse button. A duplicate schematic named Copy of Two Tone Amp is created.

2 Right-click on Copy of Two Tone Amp schematic, and choose Rename Schematic. Rename the schematic �IP3� in the Rename Data Source dialog box, and then click OK.

To change the port excitation to a fixed power:

3 Double-click on the excitation port Port PS_2 P=1. In the Element Options dialog box, click the Port tab, clear the Swept power check box, and then click OK. The port changes to Port2 P=1.

4 Edit PWR1= 10dBm and PWR2= 10dBm for the excitation Port2 P=1.

The Swept Variable wizard allows you to create measurements that are plotted, versus element parameters. The new measurement must be created from an existing IP3 source measurement. To create an IP3 measurement:

5 Click the Proj tab in the lower left window to display the Project Browser.

-10 0 10 20 30Power (dBm)

IM3

-90

-60

-30

0

30

IM1_SP[PORT_2,1] (dBm)Two Tone Amp

IM3_SP[PORT_2,1] (dBm)Two Tone Amp

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6 Right-click on Graphs, and choose Add Graph. The Create Graph dialog box displays.

7 Type �IP3� as the Graph Name, select Rectangular as the Graph Type, and click OK. The graph displays in the workspace.

8 Right-click on IP3 under Graphs, and choose Add Measurement. The Add Measurement dialog box displays.

9 Select Nonlinear Power as the Meas. Type and select IP_2 as the Measurement. Select IP3 as the Data Source Name, select PORT_2 as the Output Power Meas. Component, click on the arrows to the right to select 2 in IM Product (h1) and -1 for the IM Product (h2), and then click Add and Close.

10 Choose Simulate > Analyze.

The new IP3 vs VC measurement is derived from the original IP_2 measurement just created. Before the swept variable wizard is enabled, a destination graph must be created. To create the destination graph:

11 Click the Proj tab in the lower left window to display the Project Browser.

12 Right-click on Graphs, and choose Add Graph. The Create Graph dialog box displays.

13 Type �IP3 vs VC� as the Graph Name, select Rectangular as the Graph Type, and click OK. The graph displays in the workspace.

The swept variable for the new measurement must be enabled for tuning. This very important step must be done before the Swept Variable wizard is activated. To enable the collector voltage for tuning:

14 Click the Proj tab in the lower left window to display the Project Browser.

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15 Double-click the IP3 schematic under Circuit Schematics.

16 Locate the DCVS ID=V2 element in the schematic. Click the Tune Tool button on the toolbar and place the mouse over the V=6V parameter. A dark cross cursor displays in a small circle. Click to enable tuning.

To complete the IP3 versus VC measurement, you must activate the Swept Variable Wizard:

17 Click the Proj tab in the lower left window to display the Project Browser.

18 Expand Wizards and double-click on Swept Variable Wizard. The Swept Variable Wizard dialog box displays.

19 Select IP3 as the Source Graph and select IP3:IP_2(Port2,2_-1) as the Source Measurement.

20 Select IP3 vs VC as the Destination Graph and IP3.DCVS.V2.V in Choose Swept Variable.

21 Select Swept Variable under X-Values. Type �4� for Start, �8� for Stop, and �.5� for Step under Sweep Values.

22 Select Save Wizard State and type �IP3 vs VC� in the text box below it. Type �VC� as the Dest. Meas. Name.

23 Select 2.1 under Y-Values(GHZ).

24 Click Apply. The simulator will run at each voltage point. The final graph displays similar to the following.

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This concludes the nonlinear simulation example. You can save your work if you wish by choosing File > Save Project.

4 5 6 7 8Voltage (V)

IP3 vs VC

34

36

38

40

42

APIVc

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .USING THE ELECTROMAGNETIC SIMULATOR 7

Electromagnetic (EM) simulators use Maxwell�s equations to compute the response of a structure from its physical geometry. EM simulations are ideal because they can simulate highly arbitrary structures and still provide very accurate results. In addition, EM simulators are not subject to many of the constraints of circuit models because they use fundamental equations to compute the response. One limitation of EM simulators is that simulation time grows exponentially with the size of the problem, thus it is important to minimize problem complexity to get timely results.

EM SIMULATION IN MICROWAVE OFFICE

EM simulation and circuit simulation are complementary techniques for circuit design, and the two approaches can be used in combination to solve many design problems. Microwave Office�s EM simulator, known as EMSight, is capable of simulating planar 3D structures containing multiple metallization and dielectric layers. The structures can have interconnecting vias between layers or to ground. EMSight uses the Galerkin Method of Moments (MoM) in the spectral domain, an extremely accurate method for analyzing microstrip, stripline, and coplanar structures as well as other more arbitrary media. Properly used, this technique can provide accurate simulation results up to 100 GHz and beyond.

The following example illustrates some of the key features of the Microwave Office EM simulator.

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Creating a Distributed Interdigital Filter7

CREATING A DISTRIBUTED INTERDIGITAL FILTER

This example demonstrates how to use Microwave Office to simulate a distributed microstrip interdigital filter using the EM simulator. It includes the following main steps:

� Creating an EM structure

� Defining an enclosure

� Adding a substrate definition

� Creating a layout

� Modelling via holes

� Defining ports and de-embedding lines

� Viewing current density and electric fields

CREATE A NEW PROJECT

To create a new project:

1 Choose File > New Project.

2 Choose File > Save Project As. The Save As dialog box displays.

3 Type a project name (for example, �EM_example�), and click Save.

CREATE AN EM STRUCTURE

To create an EM structure:

1 Choose Project > Add EM Structure > New EM Structure.

2 Type �Interdigital Filter�, and click OK. An EM structure window displays in the workspace.

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HINT: EMSight uses a rectilinear grid for defining structures. When you set up designs, use the coarsest grid possible when defining structures, as this provides faster simulation time (usually without any compromise in simulation accuracy!)

SET UP THE ENCLOSURE

The enclosure defines all the dielectric materials for each of the layers in an EM structure, sets the boundary conditions, and defines the overall physical size of the structure and minimum grid units that will be used to specify conductor materials in the structure.

To set up the enclosure:

1 Double-click on Enclosure under Interdigital Filter (under EM Structures) in the Project Browser. The Substrate Information dialog box displays.

2 Select the Metric check box, and then click the arrow keys to specify units as mm.

3 Under Box Dimensions, type �10� as the X-Dimension, type �50� in X-Divisions, type �10� as the Y-Dimension, and type �50� in Y-Divisions.

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Creating a Distributed Interdigital Filter7

To define the dielectric layers of the enclosure:

4 Click the Dielectric Layers tab in the Substrate Information dialog box.

5 Select Layer 1 under Dielectric Layer Parameters. Type �3� in the edit box (near the bottom of the dialog box) in the Thickness column and type �1� in the edit box below the er column. Leave the default values in the remaining columns.

HINT: Simulations run twice as fast if they are loss-less. Therefore, set the Loss Tangent to zero and use perfect conductors to define all the metallization and vias in an EM structure.

6 Select Layer 2 under Dielectric Layer Parameters. Type �0.635� in the edit box in the Thickness column and type �9.8� in the edit box below the er column. Type �0.001� in the edit box below the Loss Tangent column and type �4� in the edit box below the View Scale column (this expands the 3D view for this layer to four times its normal thickness).

7 Delete Layer 3.

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VIEWING BOUNDARY CONDITIONS

The boundary conditions for the sidewalls of the enclosure are always perfect conductors and cannot be modified. The boundary conditions for the top and bottom of the enclosure have default perfect conductors, but they can be modified if desired. You will not modify the default boundary conditions in this example.

To view the boundary conditions:

1 Click the Boundaries tab in the Substrate Information dialog box. Then click OK to complete the enclosure set up procedure.

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Creating a Distributed Interdigital Filter7

ADDING CONDUCTORS TO THE LAYOUT

You can use Microwave Office�s EM simulator to draw physical structures for simulation. You can also import structures directly from Applied Wave Research�s layout tool, or import structures from AutoCAD DXF, GDSII or Sonnet GEO formatted files. In this example you will draw the physical layout of a microstrip interdigital filter using the EM simulator.

To draw the physical layout:

1 Choose Draw > Add Rect Conductor to add a rectangular conductor.

2 Move the cursor into the Interdigital Filter window, and press the Tab key. The Enter Coordinates dialog box displays.

3 Type �0� as the value of x and �2.2� as the value of y, and then click OK.

4 Press the Tab key again to display the Enter Coordinates dialog box. Ensure that the Re check box is selected, type �2.2� as the value of dx, and �0.6� as the value of dy, and then click OK. A rectangular conductor displays in the EM structure window.

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To draw a second rectangular conductor:

5 Choose Draw > Add Rect Conductor.

6 Move the cursor into the Interdigital Filter window, and press the Tab key. The Enter Coordinates dialog box displays. Type �4� as the value of x and �2� as the value of y, and then click OK.

7 Press the Tab key again to display the Enter Coordinates dialog box. Type �1.2� as the value of dx and �7.2� as the value of dy, and then click OK. A second rectangular conductor displays in the EM structure window.

To move the second rectangular conductor next to the first conductor:

8 Click on the second rectangular conductor in the EM structure window. Squares display at the rectangle�s corners.

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Creating a Distributed Interdigital Filter7

9 Slide the cursor over the selected conductor until the cursor displays as a cross.

10 Click and hold the mouse button down. A dx, dy readout displays in the window, as shown in the following figure.

HINT: Click the Ruler button on the toolbar to measure the dimension of conductors, offsets, or spaces in an EM structure layout.

11 Holding the mouse button down, drag the cursor until the dx, dy readout displays dx:-2 and dy:-1. Then release the mouse button to place the rectangle.

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ADDING VIAS

Vias are interconnects between substrate layers. You must add a via to ground one side of the larger conductor to the bottom of the enclosure. To add a via:

1 Choose Draw > Add Via.

2 Move the cursor into the Interdigital Filter window, and press the Tab key. The Enter Coordinates dialog box displays. Type �2.4� as the value of x and �1.2� as the value of y, and then click OK.

3 Press the Tab key again to display the Enter Coordinates dialog box. Type �0.4� as the value of dx and �0.8� as the value of dy, and then click OK. A via displays in the Interdigital Filter window, with blue squares in its corners to show that it is selected.

4 Choose Edit > Copy, then choose Edit > Paste.

5 Move the mouse into the EM structure window. An outline of the copied via displays.

6 Right-click once to rotate the via.

7 Press the Tab key to display the Enter Coordinates dialog box. Deselect Re to activate absolute coordinates. Type �2.2� as the x value and �1.8� as the y value, and then click OK. The new EM structure is as follows.

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Creating a Distributed Interdigital Filter7

VIEWING THE STRUCTURE IN 3D

The EM simulator supports multiple 2D and 3D views. To create a 3D view:

1 Choose View > 3D View. A window containing the 3D view displays in the workspace.

2 Choose Window > Tile Vertical. The views display side-by-side.

HINTS: To change the view of a 3D structure, right-click in the 3D window and choose Zoom Window, Zoom Out, or View All.

To rotate a 3D structure, click the structure in the 3D window and continue to hold down the mouse button while you move the mouse.

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ADDING PORTS AND DE-EMBEDDING LINES

The EM simulator can have electrical ports defined at the edge of the defining box (edge ports) or as a via probe coming in from the top or bottom surfaces (via ports).

To define an edge port:

1 Click on the smaller conductor in the EM structure window. Note that this conductor must be positioned exactly on the left edge of the substrate (X:0; Y:2.2) before you can add an edge port to it.

HINT: Choose View > Zoom In once or twice to magnify the view for the following steps.

2 Choose Draw > Add Edge Port.

3 Position the cursor to the left edge of the small conductor until the outline of a square displays, and click to place the port. A small box with the number 1 (indicating port 1) displays at the left edge of the conductor.

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To subtract (de-embed) an amount of electrical length from the simulation results, the reference plane for the port must be moved away from the edge of the box.

To de-embed 1mm of electrical length on port 1:

4 Right-click in the EM structure window, and choose View Area.

5 Click and hold the mouse button down to display a magnifier cursor, then drag the cursor around port 1 and the small conductor. The window zooms in on the selected area.

6 Click on port 1. Four squares display at its corners.

7 Slide the mouse over the edge of the port until the cursor displays as a double arrow.

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8 Click and hold the mouse button down to display a dx or dy readout.

9 Holding the mouse button down, drag the cursor to the right until the dx, dy readout displays dx:1. Release the mouse button to place the de-embedding line.

SPECIFY THE SIMULATION FREQUENCIES

To specify the simulation frequencies:

1 In the Project Browser, right-click on Interdigital Filter under EM Structures and choose Options. The Options dialog box displays.

2 Click the Frequency Values tab.

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3 Deselect Use Project Frequency to give local frequency settings precedence over global project frequency settings.

4 Ensure that GHz displays in Data Entry Units.

HINT: You can define the simulation frequency globally (by choosing Options > Project Options and clicking the Frequency Values tab) or locally using these steps. It is best to use the local frequency settings for EM structures as you typically want to sweep EM structures with fewer frequency points than with linear circuits.

5 Type �1� in Start, type �5� in Stop, and type �1� in Step.

6 Click Apply and then OK. Current Range displays the frequency range and steps you specified.

RUN THE EM SIMULATOR

The EM simulator is very fast for electrically small structures. To find the resonant frequency of the first resonator of the filter, you can run an EM simulation on the initial layout of the Interdigital Filter EM structure.

To simulate the structure:

1 Double-click on Information under Interdigital Filter (under EM Structures). The EM Solver Information dialog box displays the estimated simulation time for the EM structure.

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2 Click OK to close the dialog box.

3 Choose Simulate > Analyze. A progress indicator indicates what frequency is being solved and what step is taking place as the EM simulator calculates the solution. When the progress indicator disappears, the simulation is complete.

HINT: If the amount of memory required to solve a problem is greater than the available memory, try redefining the problem so that it runs within the available memory of the computer. You may need to add RAM to solve large problems efficiently.

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DISPLAYING RESULTS ON A GRAPH

To determine the resonant frequency, you must plot the return loss of the EM structure. To display this measurement on a graph:

1 Choose Project > Add Graph. The Create Graph dialog box displays.

2 Select Rectangular as the Graph Type and click OK. The graph displays in the workspace.

3 Click on the Graph 1 window in the workspace to make it active.

4 Choose Project > Add Measurement. The Add Measurement dialog box displays.

5 Select S as the Measurement, select Interdigital Filter as the Data Source Name, select the DB check box under Result Type, click Add, and then click Close.

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6 Choose Simulate > Analyze. The simulation response shown in the following figure displays on the graph. The measurement indicates that the resonant frequency is near 4 GHz.

To determine a more precise measurement of the resonant frequency, you must change the frequency range and step size of the simulation.

1 2 3 4 5Frequency (GHz)

Graph 1

-0.06

-0.05

-0.04

-0.03

-0.02

-0.01

0

DB(|S[1,1]|)Interdigital Filter

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CHANGE FREQUENCY RANGE AND STEP SIZE

To change the frequency range and step size,

1 In the Project Browser, right-click on Interdigital Filter under EM Structures and choose Options. The Options dialog box displays.

2 Click the Frequency Values tab.

3 Type �3� as the Start value, �5� as the Stop value, and �0.1� as the Step value, then click Apply. Current Range displays the frequency range and steps you specified.

4 Click OK.

5 Choose Simulate > Analyze to re-analyze the circuit. The simulation response shown in the following figure displays on the graph.

ANIMATING CURRENTS AND VIEWING E-FIELDS

Viewing the currents and electric fields of an EM structure can be useful when studying its physical characteristics. To animate the currents on the conductors:

1 Click on the 3D window of the Interdigital Filter EM structure to make it active.

2 Choose Animate > Animate Play. The animated currents in the 3D view display in the workspace.

3 3.5 4 4.5 5Frequency (GHz)

Graph 1

-0.4

-0.3

-0.2

-0.1

0

DB(|S[1,1]|)Interdigital Filter

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3 Choose Animate > Stop to turn off the animation.

To display the electric field of Layer 2:

4 Choose Animate > E-Field Settings. The E-Field Computation dialog box displays.

5 Select the Layer 2 check box and click OK.

6 Choose Simulate > Analyze to compute the electric fields.

7 Choose Animate > Play to view the currents and electric field.

8 Choose Animate > Stop to turn off the animation.

HINT: This animation illustration may vary depending upon the configuration of your computer.

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To turn off the electric field computations:

9 Choose Animate > E-Field Settings. The E-Field Computation dialog box displays.

10 Deselect Layer 2 and click OK.

COMPLETING THE FILTER LAYOUT

To complete the following filter you use some advanced editing features in the drawing window.

1 21 2

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To add the small conductor on the end of the input resonator:

1 Click on the Interdigital Filter window to make it active.

2 Choose Draw > Add Rect Conductor.

3 Move the cursor into the Interdigital Filter window, and choose View > Zoom Out until you can see the entire Interdigital Filter window. Press the Tab key. The Enter Coordinates dialog box displays.

4 Type �2� as the x value and �8.2� as the y value, then click OK.

5 Press the Tab key again to display the Enter Coordinates dialog box. Select the Re check box to change the relative coordinates. Type �-0.4� as the dx value and �-0.2� as the dy value, and click OK. A rectangular conductor displays in the EM structure window.

To draw the output resonator:

6 Choose Edit > Select All.

7 Choose Edit > Copy, and then choose Edit > Paste. An outline of the input resonator displays.

8 Move the cursor to place the outline of the copied instance on top of the input resonator, and click. The newly created instance is still selected, as follows.

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9 Choose Draw > Flip.

10 Move the cursor into the middle of the EM structure window. Click, and drag the cursor down, then release the mouse button. The selected instance flips as follows. Leave the flipped instance selected.

You must move the flipped instance to align the output line with the edge of the structure. To move the flipped instance:

11 Move the cursor over the selected instance until the cursor displays as a cross.

12 Click, and drag the outline of the instance until the output line aligns with the edge of the structure as follows, then release the mouse button.

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To create the middle resonator:

13 Click the top left corner near the left-most resonator, and holding the mouse button down, drag the cursor down and to the right so it encompasses the resonator, and then release the mouse button. The large conductor and the two vias are selected.

14 Choose Edit > Copy, then choose Edit > Paste. An outline of the copied instance displays.

15 Move the cursor to the middle of the EM structure window to move the copied instance to the middle of the window, then right-click twice to rotate the instance 180-degrees.

11

edge of structure

output line

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16 Press the Tab key to display the Enter Coordinates dialog box.

17 Deselect Re to change the relative coordinates. Type �5.6� as the x value and �9.2� as the y value, and then click OK. The new drawing is as follows.

11

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ADDING A PORT

To complete the EM structure, you must add a port to the output line. To add a port to the output line and de-embed 1mm of electrical length:

1 Click on the rightmost conductor in the EM structure window.

HINT: Choose View > Zoom In once or twice to magnify the view for the following steps.

2 Choose Draw > Add Edge Port.

3 Move the cursor to the right edge of the conductor until the outline of a square displays, and click to place the port. A small box with the number 2 (indicating port 2) displays at the right edge of the conductor.

4 Right-click in the EM structure window and choose View Area.

5 Click and hold the mouse button down to display a magnifier cursor, then drag the cursor around port 2 and the small conductor. The window zooms in on the selected area.

6 Click on port 2. Four squares display at its corners.

7 Move the cursor over the edge of the port until it displays as a double arrow.

8 Click and hold the mouse button down to display a dx or dy readout.

9 Holding the mouse button down, drag the cursor to the left until the dx, dy readout displays dx:-1. Release the mouse button to place the de-embedding line. The final layout displays as follows.

1 21 2

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10 Choose Simulate > Analyze to re-analyze the circuit.

ADDING A MEASUREMENT TO THE GRAPH

To add an s21 measurement to Graph 1:

1 Click on the Graph 1 window in the workspace to make it active.

2 Choose Project > Add Measurement. The Add Measurement dialog box displays.

3 Select Port Parameters as the Meas. Type, select S as the Measurement, select Interdigital Filter as the Data Source Name, click on the arrows to the right to select 2 in To Port Index and select 1 in From Port Index, select the DB check box under Result Type, click Add and then click Close.

4 Choose Simulate > Analyze. View the final simulations response on the graph, as follows.

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This concludes the EM simulation example. To save your work, choose File > Save Project.

3 3.5 4 4.5 5Frequency (GHz)

Graph 2

-80

-60

-40

-20

0

DB(|S[1,1]|)Interdigital Filter

DB(|S[2,1]|)Interdigital Filter

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .CREATING A VSS SIMULATION 8

In this chapter you use VSS to create a simulation of a basic quadrature phase shift keying (QPSK) system. You will learn how to use several key features of VSS. The main procedures include the following:

� Creating a new project

� Setting default system settings

� Creating a system diagram

� Placing blocks in the system diagram

� Adding graphs and measurements

� Running a simulation and analyzing the results

� Tuning the system.

CREATING A PROJECT

The first step in building and simulating your designs is to create a project. You use a project to organize and manage related designs, and everything associated with them, in a tree-like directory structure.

The example you create in this chapter is available in its complete form as qpsk.emp. This file is included in your ProgramFiles\AWR\AWR2002\ Examples\VSS\QPSK directory. You can use this example file as a reference.

To create a new project:

1 Start VSS if not already started. To start VSS, click Start on your desktop, choose Programs >AWR Suite 2002 >AWR Design Environment, or click the shortcut on your desktop. For information on installing, setting up shortcuts and starting VSS, see �Installing MWO/VSS� on page 2-1.

The AWR Design Environment window displays.

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2 Choose File > New Project.

3 To name the project choose File > Save Project As. The Save As dialog box displays.

4 Type a project name (for example, �qpsk�), choose the appropriate directory and click Save. The project name displays in the title bar.

Setting Default System SettingsIt is good practice before creating a simulation to set the default system settings.

To set default project units:

1 Choose Options >Project Options. The Project Options dialog box displays.

2 Click the Global Units tab and verify that you have the settings in the following figure. You can choose units by clicking the arrows to the right of the display boxes.

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.

3 Click OK to save your settings.

Creating a System DiagramThe system diagram is the canvas upon which you build end-to-end communications systems and graphically develop algorithms using VSS behavioral blocks. A VSS project can include multiple system diagrams, linear and nonlinear schematics and netlists.

To create a system diagram:

1 Choose Project > Add System Diagram > New System Diagram. The Create New System Diagram dialog box displays.

2 Type �qpsk�, and click OK. A System Diagram window displays in the workspace and the system diagram displays as a subgroup of System Diagrams in the Project Browser.

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Placing Blocks in a System Diagram8

Placing Blocks in a System DiagramThe Element Catalog is a database of behavioral system blocks that you can include in your system diagrams. To place a block into the system diagram you drag and drop it onto a system diagram window. You can easily reposition the blocks for convenience.

To place a block in a system diagram:

1 Click the Elem tab in the lower left of the window to display the Element Browser. The Element Browser replaces the Project Browser window.

2 If necessary, click the + symbol to the left of the System Blocks node to expand the system blocks tree.

3 Expand the Sources category, then click the Random subgroup. A Random Digital Source (RND_D) displays in the lower pane.

4 Click the RND_D block and drag it onto the system diagram, release the button, and then click to position the element as shown in the following figure.

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HINT: You can also rotate a block before positioning it by right-clicking on it.

5 From the system block list expand the Modulation category and QPSK subgroup, then select the QPSK_TX block and place it on the System Diagram.

6 From the system block list select the Channels category and then select the White Gaussian Noise Channel model (AWGN) and place it after the QPSK_TX block. Size the diagram window larger as needed.

7 From the system block list select the Modulation category, expand the General Receivers subgroup and then select the General I/Q Modulation Receiver (RCVR) and place it after the AWGN block.

8 From the system block list expand the Meters category and select two test points (TP), place one near the QPSK_TX block (above) and the other near the RCVR block. You can also click the Test Point button on the toolbar and place a test point in the diagram.

HINT: Choose Zoom > View to view different parts of the System diagram and the blocks.

9 To save the file choose File > Save Project.

Subgroup

System blocks

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Placing Blocks in a System Diagram8

CONNECTING THE BLOCKS AND TEST POINTS

To connect system blocks:

1 Place the cursor over the node of the RND_D block. The cursor displays as a wire coil symbol.

2 Click and drag the wire to the input node of the QPSK_TX block, and then click to place the wire.

3 Connect the QPSK_TX block to the AWGN block. Now connect the AWGN block to the RCVR block.

4 Connect the first TP to the output of the QPSK_TX block, and connect the TP near the RCVR block to the output of the RCVR block.

HINT: You can connect blocks by moving a block so that its node snaps to the node of the other block. When connected, the node displays a small green square. If you do not connect the first time, click the element graphic and drag the block into place. When you move a connected block, a wire is drawn automatically.

Your diagram should now look like the following diagram. Make any adjustments as needed.

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EDITING BLOCK PARAMETERS

To edit the block parameters:

1 Double-click the RND_D block in the System Diagram window. The Element Options dialog box displays.

Because M = 2, RND_D is set by default to generate a digital signal that varies between �0� and �1�.

2 Verify that M = 2.

3 Click Show Secondary. Options here let you control the random seed that is used by the RND_D block. Click OK.

4 Double-click the QPSK_TX block. If the secondary parameters are not visible, click Show Secondary.

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Specifying System Simulator Options8

.

In this dialog box you can control several parameters as well as the pulse shaping filter used on the in-phase and quadrature-phase signals.

5 On the OLVLTYP parameter row, click in the Value column to display the available options. Select Bit Energy.

6 For the PLSTYP parameter, select Rectangular and click OK.

7 Double-click the RCVR block. You do not have to set any parameters because the RCVR automatically adjusts its parameters to agree with the parameters of the transmitter. Click OK.

8 You don�t need to double-click the AWGN block. You are going to use it to control the power spectral density of the noise.

HINT: You can double-click the parameter value on the diagram to modify thevalue.

Specifying System Simulator Options To specify system simulation sampling:

1 Choose Options > Default System Options.The System Simulator Options dialog box displays.

Change to Rectangular

Change to Bit Energy

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2 Click the Simulator tab, and under Spec. Method select Symbol time. Note that there are four options under Spec. Method to define the System Sampling Rate. The parameters are interdependent and the equations that link the parameters are given above each parameter window.

The duration of the QPSK_TX transmitted complex envelope baseband symbol is set by default to 1ns and each symbol is made up of 8 samples.

3 Click OK to save the setting.

Creating a Graph to View ResultsVSS allows you to see the results of your simulations in various graphical formats. Before you perform a simulation, you must create a graph and specify the data or measurements that you wish to plot.

To create a graph:

1 Right-click on Graphs in the Project Browser and choose Add Graph. The Create Graph dialog box displays.

2 Type �Complexbaseband� in Graph Name. For Graph Type, select Rectangular and click OK. The graph displays in a window in the workspace and displays as a subgroup of Graphs in the Project Browser.

3 Repeat step 1 to create a second graph and name it �Receiver Constellation� and for Graph Type select Constellation and click OK.

4 To line up the windows, choose Window > Tile Vertical. Note that the graphs you created display in the Project Browser.

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Adding a Measurement8

Adding a MeasurementTo add a measurement:

1 Right-click on the Complexbaseband graph in the Project Browser, and choose Add Measurement. The Add Measurement dialog box displays.

.

2 For measurement type, select System under Meas. Type and select WVFM under Measurement.

3 Make sure that the test point window shows TP.TP1, click Add, and then click Close.

HINT: You can custom name a test point by double-clicking its ID number.

The qpsk:Re(WVFM[TP.TP1,10,1,1]) measurement displays under the Complexbaseband graph in the Project Browser.

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4 Right-click on the ReceiverConstellation graph in the Project Browser, and choose Add Measurement. The Add Measurement dialog box displays.

5 For Meas. Type select System, for Measurement select IQ, and for Test Point choose TP. TP2. For Data Window enter 50 and be sure the Unit type is set to Symbols as shown in the following figure.

6 Click Add, and then click Close.

Running the Simulation and Analyzing ResultsTo run the simulation:

1 Choose Simulate > Run System Simulators. Let the simulation run for 3 seconds, then click Run System Simulators to stop the simulation. The graphs are updated as follows.

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Running the Simulation and Analyzing Results8

The received constellation does not appear as expected because the power spectral density of the noise source is set to 0dB. Note that the time waveform of the complex baseband signal does not show 8 samples per symbol as you specified in the System Simulator Options dialog box.

2 Change the PWR parameter of the AWGN block to -30dB. You can double-click the parameter value on the System Diagram and change it.

3 Select the Complexbaseband graph window and click the Properties button on the toolbar.

4 In the Graph Properties dialog box, click the Traces tab. The following window displays.

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l

5 Using the drop-down symbol and line selectors, set the symbol to be a triangle and the line to be a solid line under Style. (The lines will now display on the Complexbaseband waveform).

6 Under Symbol, deselect Auto interval, change the Interval value to 1 and click OK.

7 Start the simulation, let it run for about 10 seconds and then stop the simulation. The graphs should look as follows.

On the Complexbaseband graph, you see the triangular symbols on the waveform.

Auto Interval

Interval

Line

Symbol

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Running the Simulation and Analyzing Results8

Note that your graphs may not look exactly the same as the examples due to window sizing and placement for convenience.

HINT: Click the Properties button on the toolbar to edit the appearance of any graph, or right-click in the graph to zoom in and zoom out.

8 Choose File > Save Project to save your project.

9 There are now eight samples per symbol. You can return to the System Simulator Options dialog box and change the number of Samples per symbol and Symbol time values.

TUNING A SYSTEM PARAMETER

VSS architecture uses object-oriented techniques to enable fast and efficient simulations. The real-time tuner allows you to see the results of simulations as you tune.

To tune the system diagram:

1 Click on the system diagram window to make it active.

2 Click the Tune Tool button on the toolbar.

3 Move the cursor over the PWR parameter value of the AWGN block. The cursor displays as a small cross on a black background.

4 Click to activate the PWR parameter for tuning. The parameter value changes to blue. To disengage the Tune Tool, click anywhere in the design area.

5 To start the simulation, click the Run System Simulators button. Note that the graphs are updating.

6 Click the Tune button on the toolbar.

The Variable Tuner dialog box displays.

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7 Set the values as shown above by typing in Max and Min. To observe the impact of the noise level, you should set values of Max and Min respectively to 0 and -50.

You can click on the tuning bar and slide it to adjust the values. Observe the results on the constellation graph.

8 Close the Variable Tuner dialog box.

9 Stop the simulation by clicking the Run System Simulators button on the toolbar.

10 To de-tune the PWR parameter, click the Tune Tool button, position the cursor over the PWR parameter and when the cursor becomes a cross on a black background, click on the PWR parameter value of the AWGN block. The parameter value changes to black. Double-click on the PWR parameter and change the value to 0.

CREATING A BER SIMULATION

System engineers often want to perform Bit Error Rate (BER) simulations. In this procedure you build a BER simulation.

To create a BER simulation:

1 Click on the System Diagram window to make it active.

2 Choose Diagram > Add Equation.

3 Move the cursor into the System Diagram window. An edit box displays.

4 Position the edit box in the top area of the system diagram and click to place it.

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Running the Simulation and Analyzing Results8

5 Type �Eb_N0 = sweep (stepped(0, 8, 1))� in the edit box, and then click outside of the box.

This equation sweeps the variable Eb_N0 (the energy per bit to noise density ratio) from 0dB to 8dB in increments of 1dB. Note that the PWR of the AWGN channel is set to 0dB and the simulation is being set up to increase the transmitter power.

6 Double-click on the QPSK_TX block and verify that OUTLVL parameter is Eb_N0, and the value for the OLVLTYP parameter value is set to Bit Energy. Click OK.

7 From the System Block list, expand the Meters category and the BER subgroup then select the BER block (internal reference source) and place it on the system diagram.

8 Connect the BER block to the �D� node of the RCVR block.

9 Edit the parameters of the BER block to the values shown in the following Element Options dialog box, then click OK

The BER block is now set to test 1e7 (MXTRL * TBLKSZ) bits. It registers 25 errors before a BER computation is generated for each value of Eb_N0. The BER block internally generates the original data source and compares the received bits to the transmitted bits. The last point on the BER curve at the value Eb_N0 of 8 will take the longest to plot. Note that the X-axis type parameter is a menu. Make sure you select Eb/N0 as the X-axis type.

10 To add a BER plot to the project, right-click on Graphs in the Project Browser, choose Add Graph, select a rectangular type of graph and name it �BER�.

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C R E A T I N G A V S S S I M U L A T I O NRunning the Simulation and Analyzing Results

11 In the Project Browser, right-click on the new BER graph and choose Add Measurement.

12 For Meas. Type select System BER, for Measurement select BER and for Error Meter select BER.BER1, then click Add to save the measurement.

13 To verify the obtained results with the theoretical results, you add another measurement to the BER graph with the following settings.

.

14 Click Add and Close to close the dialog box and save your measurement.

STARTING THE SIMULATION

1 Verify that the PWR parameter value of the AWGN block is 0dB.

2 Select the BER graph, then click the Properties button on the toolbar.

3 Click the Limits tab, and set the Y-axis to Log scale by selecting the Log Scale check box. Click OK.

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Running the Simulation and Analyzing Results8

4 Click the Run System Simulators button to start the simulation. As the simulation runs, the BER curve is generated. Note that the size of the received constellation becomes clearer as the power is increased or, as Eb_N0 is swept from 0dB to 8dB.

The simulation stops as soon as 25 errors are counted at Eb_N0 = 8dB. Your BER graph should look like the following.

.

5 Save the project.

CONVERTING BER CURVE RESULTS TO A TABLE

To convert the results of the BER curve to a table:

1 In the Project Browser, from the BER subgroup of the graphs right-click on BER.

2 Choose Duplicate as > Table.

3 To change the numerical precision of the table, click the Properties button on the toolbar while the table is selected.

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C R E A T I N G A V S S S I M U L A T I O NRunning the Simulation and Analyzing Results

Your diagram and graphs should now look like the following diagram. Note that exact positioning and size of your windows may vary from the following diagram.

WHAT�S NEXT?

In the next chapter you add a filter to the QPSK system and then observe the impact of filter characteristics on BER performance. In the process you will also learn about linking Microwave Office circuits to the System Diagram.

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Running the Simulation and Analyzing Results8

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ADDING AN MWO SUBCIRCUIT TO A SYSTEM 9

The circuit simulation capabilities of Microwave Office and VSS provide a unique environment to measure the impact of RF components on system performance. Measurements you can make include, for example, the impact of phase noise on BER, spectral regrowth due to the non-linearities of an amplifier and the impact of filter characteristics on BER.

In this chapter you work with features of the VSS environment and its integration with the Microwave Office circuit simulation environment. You add a filter to the QPSK system that you built in the previous chapter, and then you measure the impact of the filter on BER performance as you change filter parameters.

The basic procedures in this example include:

� Creating a schematic in the project

� Incorporating a filter design from a schematic into the system diagram

� Changing filter parameters and monitoring the impact on BER performance

� Creating a power spectral density plot project.

Creating a Schematic and Adding an Ideal MWO FilterIn this section you create a schematic and add an ideal filter designed in Microwave Office to the QPSK system diagram.

To create a schematic:

1 Open the your qpsk project if it is not already open. (To open, choose File > Open Project and select the directory where you saved �qpsk.emp�).

2 On the System diagram, double-click on the center frequency parameter value CTRFRQ of the QPSK_TX block and set the value to 5GHz.

3 Click the New Schematic button on the toolbar. The Create New Schematic dialog box displays.

4 Specify �Ideal Filter� for Schematic Name. Click OK.

5 Select the schematic window and then click the Elem tab.

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Creating a Schematic and Adding an Ideal MWO Filter9

6 In the Element Browser expand the Circuit Elements node, then General, then Filters, then select the Bandpass subgroup and place a Butterworth Bandpass Filter (BPFB) into the schematic window.

HINT: You can view the full name of an element before dragging it to the schematic by right-clicking on it and then selecting Show Details.

7 Place and connect two ports to the BPFB element. You can select ports by clicking the Ports button on the toolbar.

HINT: You can rotate a port or model by right-clicking it before placing it. You can right-click more than once to rotate the desired amount.

8 Double-click the BPFB element. In the Element Options dialog box, change the value of the following options:

� number of resonators (N) to 2

� lower frequency edge of the passband (FP1) parameter to 4 GHz

� upper frequency edge of passband (FP2) to 6 GHz

� maximum passband attenuation (AP) to 1db. The AP parameter is a secondary parameter.

9 Click OK. Your schematic should look like the following figure.

10 To set the project frequency choose Options > Project Options and then click the Frequency Values tab.

11 Set the frequency values, Start, Stop and Step as shown in the following figure.

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A D D I N G A N M WO S U B C I R C U I T T O A S Y S T E MCreating a Schematic and Adding an Ideal MWO Filter

12 Click Apply and then click OK.

13 Click on the system diagram. From the System Block list expand the RF Blocks category and the Simulation Based subgroup then select and place the (LIN_S) Behavior Model on the diagram and connect it between the AWGN and RCVR blocks. Move blocks as necessary to make room.

14 For the NET parameter of the LIN_S block, type or select �Ideal Filter� (including quotes) as shown in the following figure and click OK.

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Creating a Schematic and Adding an Ideal MWO Filter9

15 Add a test point at the output of the LIN_S block as shown in the following figure.

You can click the Test Point button on the toolbar to obtain a test point.

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A D D I N G A N M WO S U B C I R C U I T T O A S Y S T E MVerifying Filter Performance

Verifying Filter PerformanceYou now add a new graph and two measurements to create an overlay to view the power spectral density for QPSK before and after the bandpass filter.

To add a graph and measurements:

1 Add a new rectangular graph (right-click on the Graphs icon) and label it �Power Spectrum�.

2 Add a PWR_SPEC measurement to the graph. Right-click on the graph in the Project Browser, or click the Add Measurement button on the toolbar. Use the settings shown in the following figure. Specify TP.TP3 for Test Point to place the measurement after the LIN_S block. Select the DBm check box under Result Type.

3 Click Add to add a second PWR_SPEC measurement to the Power Spectrum graph.

4 Use the same settings but choose the test point prior to the AWGN block, TP.TP1.

5 Click Close.

6 Run the simulation. Note that the BER performance has degraded. Your Power Spectrum graph should look similar to the following graph.

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Experimenting with Filters9

7 Save the project as �qpskfilter.�

Experimenting with FiltersTry varying the parameters of the filter using the VSS dynamic tuning feature and observe the impact on the system BER performance.

Note that as you change the filter parameters, you can improve or severely degrade the system�s BER performance. You may also want to experiment with other filters. In fact, you can replace the ideal filter in the schematic diagram with a filter designed from actual circuit components. Upon further investigation you will discover that the primary reason for the degradation in BER performance is the impact of the filter�s phase response.

You can verify this by creating a graph that is an overlay of the PWR_SPEC of the filter output with that of a Microwave Office linear measurement named Accumulation of Linear Deviation.

Before going to the next chapter you can also experiment with the other types of filters located in the System Blocks category under Filters.

Spectrum before adding noise and filtering

Spectrum after adding noise and filtering

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A D D I N G A N M WO S U B C I R C U I T T O A S Y S T E MExperimenting with Filters

WHAT�S NEXT?

In the next chapter you add an amplifier to this design and measure its impact on the overall system.

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Experimenting with Filters9

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. . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .USING AN MWO NONLINEAR ELEMENT IN VSS 10

This chapter demonstrates how to use the Microwave Office harmonic balance nonlinear simulator in conjunction with a VSS simulation. In the example you simulate an amplifier model and then measure the impact of the amplifier on the overall system. You will also observe the resulting power spectrum and the constellation graph.

The procedures you use in this chapter include:

� Importing a Microwave Office amplifier schematic into a system project

� Compensating for phase shift

� Tuning the simulation

� Working with the VSS Vector Signal Analyzer block.

IMPORTING AN AMPLIFIER MODEL INTO VSS

In this example you add an amplifier model to the QPSK system built in the previous chapter. You can find the complete example as qpsk+filter+amp.emp in your ProgramFiles\AWR2002\ Examples\VSS\QPSK directory.

To import the amplifier:

1 Open the qpskfilter.emp project created and saved in the previous chapter if not already open. If you did not build this project, you can get the project file qpsk+filter.emp from the ProgramFiles\AWR2002\ Examples\VSS\QPSK directory. The completed project with the amplifier is available as qpsk+filter+amp.emp in the same directory.

2 In the Project Browser, right-click on Circuit Schematics and choose Import Schematic. Select the amplifier.sch schematic from the ProgramFiles\AWR2002\ Examples\VSS\QPSK directory.

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Importing an Amplifier Model into VSS1 0

The following amplifier schematic should now display in the project.

3 Verify the amplifier (NL_AMP) parameters are set to the following values.

4 Click OK.

5 Make some additional room between the QPSK_TX and the test point TP1 on the system diagram and disconnect the wire between them.

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U S I N G A N M WO N O N L I N E A R E L E M E N T I N V S SImporting an Amplifier Model into VSS

6 From the System Blocks list expand the RF Blocks category and then the Simulation Based sub-category. Select the Non-linear Behavior Model (NL_S) and place it between the QPSK_TX and AWGN blocks.

7 Connect the NL_S model to QPSK_TX and AWGN.

8 Double-click the NL_S block and set its NET parameter to reference the amplifier schematic (include the quotes).

9 After you set the NET parameter, click OK. Your system design should look like the following:

Amplifier schematic

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Importing an Amplifier Model into VSS1 0

Compensating for Phase ShiftThe amplifier introduces a 180-degree phase shift on the data. To compensate for this shift, you will place a Phase Block (PHASE) just after the NL_S block.

1 Locate the PHASE block in the Signal Processing subgroup and place it in the system as shown in the following figure.

2 Set its SHFT parameter to 180-degrees.

3 Choose Options > Project Options. In the Project Options dialog box click the Frequency Values tab and set the parameters as shown in the following figure. Click Apply to see the value display in the left column, then click OK.

4 Save the project as �qpskfilter+amp�.

5 Start and then stop the system simulation. Note the BER has improved relative to the simulation you performed with only the bandpass filter.

6 To verify the improvement, you can disable and bypass the amplifier and phase shift. To disable the NL_S and PHASE blocks, select the block, right-click and choose Toggle Enable. Note that a disabled block turns gray.

Select Single PointSet to 5GHz

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U S I N G A N M WO N O N L I N E A R E L E M E N T I N V S SImporting an Amplifier Model into VSS

7 Connect a wire from the QPSK_TX block to the AWGN block.

8 Run the simulation and note the BER values.

9 Disconnect the wire between the QPSK_TX and AWGN blocks. To enable the NL_S and PHASE blocks, right-click on the block and choose Toggle Enable.

10 Start the simulation.

Tuning the Simulation1 Select the amplifier, click the Tune Tool on the toolbar, and activate the

GAIN for tuning.

2 Click the Tune button on the toolbar to open the Variable Tuner.

3 Start the simulation.

4 Adjust the amplifier GAIN to 6dB, and observe that the BER improves.

5 Stop the simulation and set the gain to 3dB.

6 Close the Variable Tuner.

Using the Vector Signal Analyzer BlockYou will use the Vector Signal Analyzer Block to plot the instantaneous output power of the QPSK transmitter relative to the AM/AM characteristics of our amplifier.

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Importing an Amplifier Model into VSS1 0

1 From the System Block list expand the Meters category and Network Analyzers subgroup then select the Vector Signal Analyzer (VSA) block and place it above the NL_S block.

2 Connect the two ports of the VSA block to either side of the NL_S block. as shown in the following figure.

3 Save the file.

4 Add a rectangular graph and name it �AMtoAM.�

5 To add a measurement to this graph, click the Add Measurement button on the toolbar. For Meas. Type select Nonlinear Power, and for Measurement select AMtoAM.

6 For Data Source Name select the amplifier (schematic) as shown in the following figure.

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U S I N G A N M WO N O N L I N E A R E L E M E N T I N V S SImporting an Amplifier Model into VSS

7 For Power Output Component select Port_2 and select 1 for Frequency Swp Index. Click Add.

The dialog box remains open to let you add another measurement.

8 Set the measurement and parameters as follows then click Add, then Close.

9 Start the simulation. This starts the harmonic balance simulation and updates the AMtoAM graph with harmonic balance results.

10 For best graph appearance, select the AMtoAM graph, click Properties on the toolbar, click the Traces tab, and change the symbol from a triangle to none.

11 Start the system simulation. As the simulation runs, a marker moves along the plot that resulted from the harmonic balance simulation. The marker moves because you are sweeping the variable Eb_N0. The marker indicates the operating point of the system relative to the 1dB compression point of the amplifier. As you decrease the value of the 1dB compression point, note

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Importing an Amplifier Model into VSS1 0

that the operating point of this system moves into the nonlinear region of the amplifier.

Your graph should look like the following graph.

For information on the LIN_S, NL_S and VSA blocks, refer to the corresponding Visual System Simulator System Block Catalog documentation.

Note that the examples shown here use ideal behavioral models for the filter and amplifier. You can also use actual circuit models for the filter and amplifier.

WHAT�S NEXT?

For further exploration and amplifier designs you can incorporate in a system, see the example projects and design notes in the ProgramFiles\AWR2002\ Examples\VSS\Amplifier directory.

This marker indicates the operating point of the system.

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. . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .INDEX

AAdding

amplifier 10-1measurements 8-10ports 3-17subcircuits to diagrams 3-17

Adding a chip cap cell 5-18Artwork cell

adding ports to 5-16adding to a schematic element 5-11assigning 5-11creating 5-13

AWR design environment 3-1

BBasic quadriphase shift keying (QPSK) system 8-1BER simulation 8-15Bias circuit 6-7Blocks 8-2

connecting 8-4, 8-6editing parameters 8-6, 8-7placing in a diagram 8-3, 8-4

CCell libraries 3-13Circuit

analyzing 4-9optimizing 4-13, 4-18tuning 4-9

Conductors, adding to the layout 7-6Creating a new project 8-1Creating graphs 8-9Creating variables 8-15Currents, animating 7-18Curve meter 6-5

DData file

changing the ground node 5-6placing in a schematic 5-5

Data, adding to netlists 3-9Database units 5-3DC voltage and current measurement 6-10Default grid size, editing 5-3Default project units 4-2Design environment 3-2Diagram

creating 8-3Distributed interdigital filter 7-2Documentation 1-3Dynamic load line measurement 6-22

EE-fields, viewing 7-18Electromagnetic simulator 7-1Element catalog 8-4Element symbol, changing 5-7Elements

adding to schematics 3-7placing in schematics 4-3

EM simulation in Microwave Office 7-1EM structure drawings 3-9EM structures, creating 3-9

FFilter layout 7-20FLEXlm license, obtaining 2-5Frequency simulation 4-6

GGDSII cell library 5-4Graph

adding measurements 3-14

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INDEX

creating 4-7Graphs

creating 8-9Ground node, changing 5-6

HHarmonic balance 6-1Harmonic balance port 6-11

IImport process, defined 3-13Importing

a cell library 5-4data file 5-5GDSII cell library 5-4layer process file 5-2

Importing a data file 5-5Installing MWO/VSS 2-1

LLayer process file, importing 5-2Layout

creating 3-9, 3-11creating from schematic 5-1exporting 5-26viewing 5-11

Layout cellanchoring 5-12

Linear simulators 4-1Lines

de-embedding 7-11Load line measurement 6-22Lumped element filter, creating 4-1

MMeasurements 3-15

adding 8-10Measurements, adding 4-7Measuring Ip3 vs voltage 6-27Microstrip elements, placing 5-7MTRACE element 5-20

NNetlists, creating 3-4, 3-5Nodes 4-5Nonlinear element 10-1Nonlinear measurements 6-2Nonlinear model 6-4Nonlinear simulation frequencies 6-13Nonlinear simulator 6-1

OOnline help 1-3Optimizing ciruits 4-13Optimizing with subcircuits 4-18

PParameter

tuning 8-14Ports

adding 3-17, 7-11adding to an artwork cell 5-16

Ports and wires 3-8Pout vs. frequency measurement 6-21Power amplifier circuit 6-2Project

create new 5-2creating 3-4, 4-1, 4-2creating new 8-1opening 3-4saving 3-4setting default units 4-2

Project browser 3-2

RResults, displaying on graphs 7-16

SSchematic

copying in the project browser 6-24creating 3-5, 4-2editing 5-18placing elements in 4-3

Signal gamma measurement 6-14

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INDEX

Simulation frequency 3-15, 4-6, 7-13Single-tone analysis 6-1Snapping layout cells 5-22Starting Microwave Office 3-1Structure drawings 3-10Subcircuits

adding to a diagram 3-17, 9-1adding to a schematic 3-4, 3-8, 6-17

Swept variable wizard 6-27Symbol, changing 5-7System diagram 8-4

creating 3-6linking to MWO 9-1

System diagrams 3-6System settings, defaults 8-2System simulation sampling 8-8

TTechnical support 1-4Third order intermodulation measurement 6-26Tuning a circuit 4-9Tuning a system parameter 8-14Two-tone analysis 6-2Two-tone harmonic balance port 6-24

VVariables

creating 8-15Vector complex analyzer block 10-5Vector variables 4-14Vendor libraries 2-1VIAS, adding 7-9Viewing a layout 5-11Viewing structures in 3D 7-10

WWebsite support 1-4Wires

adding 3-17Wires, connecting 4-4

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INDEX

Index-4 MWO/VSS 2002