Electronic System DesignElectronic System DesignWireless 1 PresentationWireless 1 Presentation

Dec 7th, 2000

Dec7th 2000

Overview• Objective• Group Designations• Timeline• System Overview

– USB Interface Robert– TRF6900 Transceiver Robert– Antenna Jimmy– Testing Imran– Packaging Jason

• Summary & Conclusions Clay• Demonstration

Dec7th 2000

Objective

• Wireless Communication B/W PC1 & PC2 via USB Port

CommunicationSystem

PC 1

CommunicationSystem

PC 2

Dec7th 2000

Group Designation

Wireless Group 1

EVM Group USB Group Antenna Group Testing Group Packaging Group

Operation ofTRF6900

Package for FinalProduct

Test Plan&

Hardware Issues

Antenna forTransmission

USB Interface b/wPC & TRF6900

Dec7th 2000

System Overview

EZ-USB ParallelOut

USBPort

USB Group

ParallelPort TRF6900

EVM Group

RX_DATAFilteringCircuit

Testing Group

MechanicalAntennaSwitch

Antenna

Antenna Group

Packaging Group

USB Interface & Software USB Interface & Software GroupGroup

Group LeaderRobert Dickerson

Group MembersClay AyersAsad Khan

TI SoftwareTI Software•Used to diagnose and setup the TRF6900•Parallel port problems

•Lacked the ability to be used with the USBSIMM•Inability to cancel a diagnostic test pattern

““Improved” TI SoftwareImproved” TI Software

““Improved” TI SoftwareImproved” TI Software

•Automatically selects USBSIMM when connected

•Non-integer testing durations

•Option to reset settings to default when switching between TX/RX modes•Changed frequency error adjustment to amount of error in the signal

•Will program the TRF6900 with the parallel port

InstantSquawkerInstantSquawker

InstantSquawkerInstantSquawker

•Chat program with file transfer capabilities•Uses a basic protocol between itself and the USBSIMM board•Automatically detects and interfaces with the

USBSIMM module and programs the TRF6900 on connection

USB FirmwareUSB FirmwareStarting Point

Initialize USBSIMM

Reset and Disable TRF6900

Do Nothing in Main Loop

USB FirmwareUSB Firmware

•Setup packets from the PC

•PC request to read the IN buffer

•Serial port TX/RX

•Data packets to send over the RF link

EVM Group PresentationEVM Group PresentationGroup Leader: Imran Bashir

Members: Jeff Allen, Asad Khan, Fakhri Sadeh, Wendy Johnston,

Jason Benavidez

Dec 7th, 2000

Dec7th 2000

Overview

• TRF6900 Transceiver• Transmitter• Receiver• General Specifications• Why TRF6900?

Dec7th 2000

TRF6900 Transceiver

Dec7th 2000

Transmitter

Serial Interface

Data

Clock

Strobe

Direct Digital Synthesizer (DDS)

Crystal Oscillator

PLL VCO Tank Circuit

Filter / Impedance Matching

LOCKDET

VCO

Antenna

2nd Order Loop Filter

AmplifierAmplifierPowerAmplifier

Mode

STDBY

TX_DATA

Dec7th 2000

Receiver

Impedance Matching

Carrier

Data Slicer Data Switch FM / FSK

Demodulator

Tank Circuit

External Circuit for

LPF

Capacitor for VREF

RX_DATA

LNA RF Amplifier

RSSI (OOK/ASK)

Pre-Select Filter IF Amplifier (1)

IF Amplifier (2)

BPF (1) BPF (1)

LPF Amplifier/ Post Detection

Amplifier

Antenna

Dec7th 2000

SpecificationsTRF6900

48-pin PQFPPackage

2Standby Current (A)

2.2 – 3.6Operating Voltage (Volts)

5Power Output (dBm)

FSK, narrow-band FMStandard Supported

850-950Frequency (MHz)

TRF6900Parameter Name

Dec7th 2000

Why TRF6900?

• Availability• Donation from Texas Instruments• Suitable for the Project’s Objective• Availability of Reference Material &

Technical Support

ANTENNA DESIGN GROUP

James FurseAden Wilson

Dec7th 2000

Objectives – Antenna Design

• Compact Design

• Center Frequency of 915 MHz

• Low VSWR

• High Gain

• Circular Polarization

Dec7th 2000

Objectives – RX/TX Switching

• Low Insertion Loss

• Fast Switching Speed

• TTL Level Input

Dec7th 2000

Antenna Design Scheme

• Initial antenna design and evaluation• Optimize characteristics by varying antenna

dimensions and configuration• Perform preliminary tests with network

analyzer to determine effects of changes• Implement desirable modifications and

perform radiation pattern and gain tests

Dec7th 2000

Experimental Modifications • Increased ground plane area • Increased pitch angle

• Varied helix diameter

• Varied number of helix turns

• Implemented shunt feed configuration

Dec7th 2000

Equipment Setup for Radiation Pattern And Gain Measurements

Anechoic Chamber

AntennaUnderTest

ProbeAntenna

NetworkAnalyzer

PC(Data

Collection)

Dec7th 2000

Anechoic Chamber Setup

Dec7th 2000

Network Analyzer and Antenna Rotation Unit

Dec7th 2000

Milestones

• 10/01/00 Select Antenna Design

• 10/08/00 Complete Prototype

• 11/15/00 Implement RX/TX Switch

• 11/20/00 Successful PC to PC Communication

• 12/05/00 Design Complete

Dec7th 2000

NMHA Operation

• Normal Mode

• Self Resonance

• Direction of Maximum Radiation

• Elliptical Polarization

• Ideal E-Plane Radiation Pattern

Dec7th 2000

Ideal E-Plane Radiation Pattern

sin4

)( 2bjsReINE

Rjo

Dec7th 2000

Final Antenna Design

Dec7th 2000

Antenna Specifications

• Turns 5• Diameter .3125• Spacing .48 • Pitch Angle 26 • Helix Length 2.4 • Shunt Feed Configuration

Dec7th 2000

Network Analyzer – Return Loss

Dec7th 2000

Network Analyzer – Smith Chart

Dec7th 2000

Network Analyzer - VSWR

Dec7th 2000

Anechoic Chamber Measurements

90 deg

270 deg

180 deg 0 deg

H-Plane Radiation Pattern (915 MHz)

Dec7th 2000

Anechoic Chamber Measurements

90 deg

270 deg

180 deg 0 deg

E-Plane Radiation Pattern (915 MHz)

Dec7th 2000

Anechoic Chamber Measurements

900 905 910 915 920 925 9300

1

2

3

4Measured Gain

Frequency in MHz

dB

Dec7th 2000

RX/TX Switching

Normal ModeHelical AntennaRX/TX Switch

RX

TX

Testing Group PresentationTesting Group Presentation

Group Leader: Imran BashirMembers:

Jeffery Allen, Asad Khan, Fakhri Sadeh, Farhan Khan

Dec 7th, 2000

Dec7th 2000

Overview

• Test Setup• Software Issues

– Speed– RSSI

• Hardware Issue– RX_DATA– Solution

• Design 1• Design 2

– Final Circuit

Dec7th 2000

Test Setup

8 V

Duplexer TRF6900 EVMRX_DAT

A

O’scopeOR

Logic Analyzer

PC (RX)

Running TRF6900.exe

Ver. Beta3

DB25 femaleTo DB25 male

EZ-USB USB Port

Parallel OutTRF6900 EVM

TX_DATA

O’scopeOR

Logic Analyzer

PC (TX)

Running TRF6900.exeVer. Beta 3

DB25 femaleTo DB25 male

EZ-USB ParallelOut

USBPort Duplexer

D.C. Power Supply

8 V

Dec7th 2000

Software Issues

• Speed– Modified Software for Faster PCs

• RSSI– Very Weak Signal from TRF6900– Turn RSSI “ON” in Software

Dec7th 2000

Hardware IssuesNoise Issue

• Spikes on RX_DATA During FSK Test

Voltage Spikes

Dec7th 2000

Hardware IssuesNoise Issue

• Noise on RX_DATA After FSK Test

Dec7th 2000

Hardware IssuesNoise Issue: Solution

Vcc

Input A

Input B

GND

Input A Input B Output

Dec7th 2000

Hardware IssuesNoise Issue: Solution

• 1st Design

TLV3402 Analog Comparator

Dec7th 2000

Hardware IssuesNoise Issue: Solution

• Problem:– RSSI Signal is High After FSK Test

During FSK Test

After FSK Test

Dec7th 2000

Hardware IssuesNoise Issue: Solution

• 2nd Design

• Cleans Spikes in RX_DATA• High Output After FSK Test

Dec7th 2000

Packaging Group

Group LeaderJason Benavidez

Group MembersWendy Johnston

Jeff Allen

Dec7th 2000

Group Objectives

• Packaging the EVM Board, USB SIMM Board, Antenna, and All Related Components for Testing Purposes

• Construct Necessary Jumpers and Connections Internal to the Device

• Design and Fabricate a Single Package Solution for Final Commercial Product

Initial Packaging

Dec7th 2000

Initial Packaging DesignBlock Diagram

EVM BOARD

POWER CONNECTIONS

PARALLEL PORT SMA CONNECTORS TO RX/TX

OSCILLOSCOPE CONNECTIONS TO BOARD

PWR SWITCH

USBSIMM

USB PORT

PWR (adapter)

IN

Yellow represents future upgrades

Dec7th 2000

Initial Design Features

• Provide Protection & Stability for EVM• Provide Permanent Connections for Power

Supply From External DC Power Source• Allow Easy Access to RX/TX Data Terminals

for Testing Purposes• Allow Easy Hook up to Testing Equipment

Dec7th 2000

Initial Package Design

Dec7th 2000

Package Layout

Final Packaging

Dec7th 2000

Final Packaging DesignBlock Diagram

EVM BOARD

PWR SWITCH

USBSIMM

USB PORT

PWRIN

10-12 V

ANTENNA SWITCH

POTPARALLEL

PORT

PWRIN

28 V

LOGIC CIRCUIT

VOLTAGE REGULATOR

5 V

VOLTAGE REGULATOR

8 V

Dec7th 2000

Final Design Features

• USB Data Input Capability• Lighted On/Off Switch• Impact Resistant Polystyrene Box• Internalized Antenna

Dec7th 2000

Final Package

Dec7th 2000

Final Package

Dec7th 2000

Final Package

Dec7th 2000

Project Demonstration

Dec7th 2000

Supporters

•Texas Instruments

•Mousers Electronics