Arrays

电子科技大学 贾宝富 博士

阵列天线仿真

阵列天线仿真

Array Overview

Analysis Approaches

Unit Cell Analysis with Master / Slave

Boundaries

Unit Cell Simplification

Master/Slave Boundaries

Unit Cell Creation

Verifying the Unit Cell Geometry

Floquet Ports Overview

Floquet Mode Visualization

Floquet Ports: Determining the Modes to Include

Modes Calculator

Floquet Port Setup

Floquet Port Setup

What if the Lattice is Triangular

Floquet Port Setup

Floquet Port Setup

Floquet Port Setup

Results – Matrix Data

Results: Return Loss/Insertion Loss

Finite Array Analysis

Challenges for Large Finite Array Modeling

Domain Decomposition Overview

Solution: Finite Array Domain

Decomposition

Finite Array DDM Tool Advantages

How It Works!!!

How It Works!!!

How It Works!!!

How It Works!!!

Probe Fed Patch Array with Feed Network

Finite Phased Array Setup Using DDM Unit cell is analyzed to create mesh

Unit cell mesh is then replicated to form remaining elements in the array

Mutual Coupling Data

Active Return Loss with Phase Taper

Embedded Element Patterns

Array Pattern in the E-Plane

Array has no phase shift taper so thebeam is pointed toward boresite

Sidelobe Levels are -10.86dB and-13.23 dB in the E & H Planes.

Array Pattern Scanned to 45o in the E-Plane

Explicitly Solved Patch Array vs. DDM Comparison

用 CST Microwave Studio仿真阵列天线

Outline

Antenna simulation Different solvers for different antennas

Antenna array simulation Small arrays Feed networks Large arrays Active element pattern

Online demo

A small selection...

Antenna Simulation Different antenna types require different

solver technologies.

Transient Solver

Frequency Solver

Integral Equation Solver

阵列天线仿真基本方法

由单个天线计算天线阵； 未考虑天线之间的耦合。

由整体模型单独激励计算辐射场； 计算涉及天线结构之间的影响。

整体模型，同时激励； 同时涉及结构和激励状态的影响。

计算模型 单个天线的设置

求解设置

求解设置

天线阵设置

计算结果

单独计算用后处理叠加

求解设置 频率设置与前面相同

求解设置

计算结果

计算结果

计算结果

计算结果

计算结果

设置后处理

计算结果

直接计算方式

模型、边界条件和场观察器等与前面的设置相同。

求解设置

计算结果

计算结果

Antenna Arrays

Small Arrays

Distributed Computing (DC)

Multiple Element Excitation

Array Feeding Networks

Large Arrays

Infinite Array

Infinite Array

FarfieldArray

Infinite Array

Active Element Pattern

Finite Array Analysis

CST Array Wizard

Summary

用 HFSS仿真阵列天线

序言 HFSS 计算实际的阵列天线是基于阵列天线中的一个单元。对于模式驱动和端口驱动的设计，使用分布仿真过程。使你能够快速定义、显示和仿真阵列天线设计。

设计步骤

1. Draw the unit cell, containing all appropriate boundaries and source definitions.

2. Create the antenna array, including name, dimensions, master and slave boundaries where needed for conformal meshing, and selection of row and column master/slave pairs for implicit definition of lattice propagation vectors. Designate which cells are active, passive, and padding.

3. Setup the distributed processor pool. Designs with arrays require HPC licenses.

4. Provide a memory statistic for the amount of RAM guaranteed on each DSO processor.

Creating a Unit Cell for an Array

The unit cell can be rectangular, parallelogram or hexagonal.

You must define appropriate master and slave boundaries, as well as other boundaries required for the model. Deleting a master or slave boundary that is referenced by an existing array also deletes the array. Typically, you define master and slave boundaries as opposite sides of a cell.

简单阵列的单元电路

In such cases, with master and slave boundaries on opposite sides, the array sides align.

In making source definitions for unit cell for the unit cell, you cannot assign a Floquet port.

• Each driven Modal or driven Terminal design can contain a single array.

复杂阵列设置 However, you can

arrange master and slave boundaries to create an offset array. In such cases, you create both a master and a slave boundary for corresponding sections of a cell side, and assign master and slave to create offset alignment.

With all boundaries defined in this manner, the array can be offset.

Create Array Command The Create Array command is

enabled for Modal and Driven Terminal problems after you have assigned master and slave boundaries to your unit cell model. You can access the command in three ways: click HFSS>Model>Create Array, right-click on the Model icon in the Project tree and select Create Array from the shortcut menu, or select the unit cell in the modeler window, and select Create Array from the short-cut menu.

This displays the Regular Planar Array dialog where you specify parameters for Number of Cells, Unit Cell Position and Lattice Vectors.

Create Array Command If you have Visible enabled, you

can see any changes. To Define Lattice Vector

directions for A and B Vectors, specify the master boundary.

To define the array size, for the A and B vectors, specify the number of cells for each row and column, respectively.

For example, the following figure shows the results when the initial Lattice Vectors are swapped.t

To create an irregular array, select the Active Cells tab, select the radio button for Mouse makes cell as Padding

Create Array Command Once you have

specified the parameters, the Array object appears in the Project tree under the Model. Only one Array is permitted for a model. The Create Array command is disabled if an array is defined.

By selecting the Array icon in the Project tree, you right-click for the short cut menu.

Create Array Command Selecting Delete removes the

array from the Model. Selecting Properties displays

the Regular Planar Array dialog.

Selecting Visualize Array lets you toggle the array display. A check mark indicates that the array is being displayed.

With the Array icon in the Project tree selected, if you have a docked Properties window displayed, you can see and edit Array Properties. All edits are undoable and informational messages will be posted to the Message window when design data is deleted.

Setup and Run an Array Simulation

There is no change in the GUI for setting up the adaptive simulation for designs with an array. However, the solution quantities of the virtual cells will be available for convergence setup (In both adaptive and interpolating sweep). There are no changes in the way convergence information is presented on the Convergence tab of the Solution Display panel.

If your design contains a virtual array, the setup can have some differences.

• Enable Solver Domains should not be checked (these are UI defined domains, not solver defined domains).

• Setup the distributed processor pool. Designs with arrays require HPC licenses.

• General Setup for Virtual Array Simulation for Matrix Convergence, if you choose Selected Entries.

• Interpolating Sweep Advanced Options for Array Simulation • Fast sweep is not supported.

Setup and Run an Array Simulation You can also setup the expression cache

at solve setup. The expression cache interface for accessing array elements is the same as those used in report setup.

• Use the Active Cells tab on the Regular Planar Array dialog to designate which cells are active or passive for a simulation. You can make All Active, All Passive or select which cells are active or passive. The more active cells there are for a simulation, the more processing required. By default, clicking the corresponding array elements toggles the current selection, You can also choose the Mouse makes cell setting to click for Active or Passive, whichever is most convenient. Clicking on a row or column number applies the mouse click command to all cells in that row or column. Dragging the cursor over cells performs the current operation on them.

Setup and Run an Array Simulation It is important to understand the impact of passive ports on antenna

parameters. For accepted power calculations, passive ports are not included when computing the total power passing through the union of all port surfaces. This means that the passive ports can be viewed as a loss mechanism for the device and it is not equivalent to viewing the passive ports as active ports with zero excitations.

• Report setup for Arrays. The solution/matrix quantities are grouped by category. The entries

in each category are listed according to their [row, column] order in the corresponding matrix.

The entry in [row1, column1] will be listed first, followed by [row1, column2], … [row1, columnN], [row2, column1], … [row2, columnN], … [rowN, columnN]. Note that the [row, column]

order of each entry in the matrix is controlled by the 'Matrix' order as specified by user.

The existing "Filter" capability can help locate the desired quantity from the potentially very long list.

General Setup for Virtual Array Simulation For a project with an array the

General Setup some differences appear in how you can specify Matrix convergence.

If you select Matrix Convergence, and click Set Magnitude and Phase, you will see the Matrix convergence dialog. In the Matrix Convergence dialogue, if for Entry Selection you choose Selected Entries, (rather than All or Diagonal/Off Diagonal), you will see scrollable drop down menus that let you select from all Array elements to define pairs of Matrix entries.

Interpolating Sweep Advanced Options for

Arrays For an Interpolating Sweep

Advanced Options, if you select Use Selected Entries,

clicking the Select Entries button displays an Interpolation Basis Convergence dialog that lists the Array elements.

Note that the matrix entries are listed according to the Matrix Sort Order as specified by user.

Entry Selection can be All, Diagonal, or Off-Diagonal. Mode Selection can be All, Dominant Only, or Higher-Order Only.

Array Visualization You control the visualization of an

array by selecting an existing Array in the Project tree and toggling the Visualize Array command on the short-cut menu.

Virtual objects in an array display as wire frames. If the all virtual objects for an array do not appear in the view modeler window, perform a View>Fit All operation. If you change the view, you can also use Ctrl-D to fit the array into the current view.

You can disable the array visualization by clicking on the Visualize Array option again. A check mark appears in front of Visualize Array if the option is already ON. This option will also be present in general active view visibility options, View>Active View Visibility.

Post Processing for Array Models Solution quantities of both physical and

virtual cells are available for post-processing.

Radiation fields (near and far) post processing is over the whole array. You can plot and animate fields on non-model cut planes, vectors, and points, as well as on selected model object faces. Any padding cells in or around the array are treated as background material.You can plot and animate fields on cut planes, vectors, and points.

You can use the Fields calculator to define calculated expressions. HFSS can also post process individual cells in an array one at a time. You

can select an arbitrary cell and do fields post processing on that cell. HFSS post processes on a single user selected cell in the array.

For Port Field Display there is no GUI change. Only physical ports/terminals will be listed. There is no need to support visualization of user-selected cell (like field overlay plot) because the field patterns of the virtual modes are the same as those in the physical cells.

Reports for Arrays There are some differences in the Report setup for Arrays.

1. The solution/matrix quantities are grouped by category. The entries in each category are listed according to their [row, column] order in the corresponding matrix.

The entry in [row1, column1] will be listed first, followed by

[row1, column2], … [row1, columnN], [row2, column1], …

[row2, columnN], … [rowN, columnN]. Note that the [row, column] order of each entry in the matrix is controlled by the 'Matrix' order as specified by user.

2. The existing "Filter" capability can help locate the desired quantity from the potentially very long list.

Field Plots for Arrays You can generate field plots on object faces, as well as on non-model

planes, lines, and points. The plots display calculated fields where ever the selected geometry intersects the array cells based on whether the cells are active, passive, or padding in the array properties. Locations designated as padding are treated as background material in field calculations. The virtual cells do not need to be visible to affect the generated field plots.

You can also create animations of field plots. If the plotted geometry is controlled by a swept variable (such as plane angle or a point location) the animation displays the correct values whereever they intersect the array based on the designations as active cells, passive cells, or padding cells.

Fields Calculator Applications for Arrays

Geometries selected for Fields Calculator expressions can intersect any active, passive, or padding cells defined for the array. You can generate animated field output in which each frame is a snapshot of the fields on a different plane of the modeled volume. The Fields Calculator cookbook describes an example of the technique. Any derived field quantity can be plotted in this manner.

Fields Post Processing on a Designated Array Cell

For post processing fields information for arrays, you can select an arbitrary cell and do fields post processing on that cell.

The unit cell mesh from position (1,1) will be translated to the user selected cell and fields will be plotted in the user selected cell.

The procedure is:1. Select objects in the unit cell2. Use the Array dialog to specify

the cell to post process for fields, either by clicking on a the corresponding array position indicator in the Post Processing Cell tab in or by giving the A and B direction indices (row and column respectively).

The Field plot will be visible in the user selected cell.

Radiation fields post processing will be over the whole array.

Jsurf is calculated inside the geometry of the cell but it will be equal to 0 along cell borders.