Radio Frequency Design to Support Software Transceiver for Wireless Communications

Transcription

1 Radio Frequency Design to Support Software Transceiver for Wireless Communications Author: Cazzie Williams Western Michigan University Whirlpool Corporation Advisor/Sponsor: Dr. Frank Severance and Dr. Bradley J. Bazuin Western Michigan University, Dept. of Electrical and Computer Engineering

2 Presentation Overview Introduction Project Description Need and Application Goals and Benefits Detailed Design Receiver Transmitter Test Results/Conclusions Acknowledgments Questions 27 October, 2001 MSGC

3 27 October, 2001 MSGC Software Transceiver Overview RF to IF Receiver A to D Convert Digital Down- Converter Comm. Tower Digital Signal Processor Satellite IF to RF Transmit D to A Convert Digital Up- Converter IBM Compatible This work focused on the RF to IF Receiver and IF to RF Transmitter

4 27 October, 2001 MSGC Project Description! The complete project goals were to define, design, develop, and demonstrate a flexible, electrical and software programmable transceiver (FEAST) for wireless communications.! The receiver path collects, downconverts and filters radio frequency (RF) energy to an intermediate frequency (IF). The IF is digitally sampled, digitally filtered and downconverted, and then processed in a programmable digital signal processor (pdsp). Audio or data outputs may be provided.! The transmitter path inputs audio or digital data to the pdsp. The pdsp processes the information before it is digitally upconverted and filtered into a digital IF. The digital IF is converted into analog and then filtered and upconverted to the desired RF band for transmission.

5 27 October, 2001 MSGC Needs and Applications Provide critical radio frequency (RF) to intermediate frequency (IF) translation. RF in the Instrumentation, Scientific, and Measurement (ISM) band ( MHz) ADC/DAC IFs designed for 64 Msamples-per-sec, 16 MHz center frequency, 26 MHz bandwidth. Tested using 50 Msps, 12.5 MHz center frequency and 26 MHz (aliased) BW. Provide a useful dynamic range for signals and a low noise figure to Define and provide signal gain to load, not saturate, the ADC Define a low noise figure architecture to provide high dynamic range and high sensitivity to weak RF signals.

6 27 October, 2001 MSGC Stages of a Receiver HPF Fc = 915Mhz HPF 902Mhz to 928Mhz Synthesizer Fc = 788Mhz Fc = 140Mhz IF Filter Fc = 140Mhz Fixed Local Oscillator Fc =152.5Mhz Fc = 152.5Mhz LPF Fc = 12.5Mhz LPF Fc = 12.5Mhz Fs/2 D to A Convert

7 27 October, 2001 MSGC Input RF Waveform RF Receiver 1 Preselector IF Filter Lowpass Filter Output to ADC LO Input to RF Mixer LO Input to RF Mixer -3 dbm Attenuator RF to IF Converter Signal Generator IF Filter LO IF to BB Converter LO output to RF Mixer 10 dbm Antialiasing Chart of the Components in RF-to-IF Converter Component List Type Company Make Model or Part Number 1 High Pass Filter Mini-Curcuits SHP Low Noice lier (LNA) Mini-Curcuits ZFL 1000HLN 3 Mixer Mini-Curcuits ZFM 5X 4 IF Filter (BPF) SAWTEK lier Mini-Curcuits ZFL Mixer Mini-Curcuits ZFM 3 7 Low Pass Filter Mini-Curcuits SLP 30 8 lier Mini-Curcuits ZFL Voltage Oscillator (VCO) Mini-Circuits ZOS Signal Generator HP 8656A

8 27 October, 2001 MSGC Gain & Noise Computation Chart of the Gain & Noise of our RF to IF converter Component Assignments Gain (db) Gain (linear) Noise (db) Noise (linear) Total Gain (db) Total Gain (linear) Total Noise Figure (linear) Total Noise Figure (db)

9 27 October, 2001 MSGC Receiver Signal Power Levels Thermal Noise (kt) 26 MHz BW (ktb) Receiver NF (db(ktb)+nf) Receiver Noise Floor Minimum Detectable Signal (ktb + NF + Detection Threshold) ADC LSB < Noise Floor SNR Defines Max Input Gain Sets Max Input to ADC +10 dbm ADC Max dbm dbm Signal Power Considerations NF 6.15 db 26 MHz db Gain db ADC SNR 68 db dbm dbm dbm Noise Power Considerations -174 dbm/hz

10 27 October, 2001 MSGC Transmiter Transmitter dbm Attentua Postselector IF Filter -10 dbm Attentua Lowpass Filter Input from DAC LO Input to RF Mixer LO Input to RF Mixer -3 dbm Attenuator Filtered Preamp Signal Generator IF to RF LO IF to BB Converter LO output to RF Mixer 10 dbm Baseband Filter Chart of Components for the IF-to-RF Converter Component List Type Company Make Model or Part Number 1 lifer Mini-Curcuits ZFL High Pass Filter Mini-Curcuits SHP Mixer Mini-Curcuits ZFL 5X 4 lifer Mini-Curcuits ZFL IF Filter (BPF) SAWTEK Mixer Mini-Curcuits ZFM 3 7 Attenuator Mini-Curcuits SAT 10 8 lifer Mini-Curcuits ZFL Low Pass Filter Mini-Curcuits SLP Voltage Oscillator (VCO) Mini-Circuits ZOS Signal Generator HP 8656A

11 27 October, 2001 MSGC Gain & Noise of the IF to RF Converter Chart of the Gain & Noise of our IF to RF converter Component Assignments Gain (db) Gain (linear) Noise (db) Noise (linear) Total Gain (db) Total Gain (linear) Total Noise Figure (linear) Total Noise Figure (db)

12 27 October, 2001 MSGC Test Plan In order to test the validity of the system, it is planned to execute a series of operational tests based on the following capabilities: Continuous Wave (CW) Tests litude Demodulation (AM) Frequency Demodulation (FM)

13 27 October, 2001 MSGC Continuous Wave Tests Test 1: Input to ADC Input Signal 140 MHz Lowpass Filter Output 0 dbm LO Input to RF M ixer -3 dbm Attenuator LO IF to BB Converter LO output to RF Mixer 10 dbm Antialiasing Gain/Loss to Power chart to determine I/P power Component Number Gain/Loss (db) Power (dbm) ignored 6-5 Power I/P by signal generator -14

14 27 October, 2001 MSGC Continuous Wave Tests Mixing (with high-side injection) Frequency needed from the VCO: ( ) 140 = Voltage needed to produce MHz (constant fixed voltage) MHz = 7.7 MHz (V 1) MHz V = 7.82 VDC (constant fixed voltage) Mixing Products MHz = 12.5 MHz MHz = MHz Low Pass Filter Only 12.5MHz passes to the ADC

15 27 October, 2001 MSGC Test 1 Results Spectral Analysis of 140MHz Demodulated Signal Frequency (Hz)

16 27 October, 2001 MSGC Test 2 (IF Receiver Test) Continuous Wave Tests Input Signal 140 MHz 4 IF Filter Lowpass Filter Output 0 dbm LO Input to RF Mixer -3 dbm Attenuator IF Filter LO IF to BB Converter LO output to RF Mixer 10 dbm Antialiasing Gain/Loss to Power chart to determine I/P power Component Number Gain/Loss (db) Power (dbm) ignored Power I/P by signal generator -21.7

17 27 October, 2001 MSGC Continuous Wave Tests Mixing (with high-side injection) Frequency needed from the VCO: ( ) 140 = Voltage needed to produce MHz (constant fixed voltage) MHz = 7.7 MHz (V 1) MHz V = 7.82 VDC (constant fixed voltage) Mixing Products MHz = 12.5 MHz MHz = MHz With a Low Pass Filter Only 12.5MHz pass to the ADC

18 27 October, 2001 MSGC Test 2 Results Spectral Analysis of IF Receiver Test Frequency (Hz)

19 27 October, 2001 MSGC AM Demodulation Test Input RF Waveform Radio tower 1 Preselector IF Filter Lowpass Filter Output to ADC LO Input to RF Mixer LO Input to RF Mixer -3 dbm Attenuator Signal Generator LO LO output to RF Mixer 10 dbm RF to IF Converter IF Filter IF to BB Converter Antialiasing

20 27 October, 2001 MSGC FM Demodulation Test Input RF Waveform Radio tower 1 Preselector IF Filter Lowpass Filter Output to ADC LO Input to RF Mixer LO Input to RF Mixer -3 dbm Attenuator RF to IF Converter Signal Generator IF Filter LO IF to BB Converter LO output to RF Mixer 10 dbm Antialiasing

21 ISM Band 27 October, 2001 MSGC

22 27 October, 2001 MSGC Project Results:ISM Transmitting & Receiving Receiver Preselector IF Filter Lowpass Filter Output to ADC LO Input to RF Mixer LO Input to RF Mixer -3 dbm Attenuator RF to IF Converter Signal Generator IF Filter LO IF to BB Converter LO output to RF Mixer 10 dbm Antialiasing Transmiter -20 dbm Attentua 1 2 Postselector IF Filter dbm Attentua 9 Lowpass Filter Input Signal from DUC to 2 MHz LO Input to RF Mixer LO Input to RF Mixer -3 dbm Attenuator Filtered Preamp Signal Generator IF to RF LO IF to BB Converter LO output to RF Mixer 10 dbm Baseband Filter

23 27 October, 2001 MSGC Project Results Specification Meet Yes (Y) No (N) Partially (P) 1 Real time data collection and storage for post-processing evaluation P 2 Snap shot data analysis capabilities performing spectral analysis and signal correlation P 3 Digital filtering for both general spectrum, pre-demodulation and post-demodulation filters Y 4 5 Simple demodulation processing of AM, FM-narrowband, FMwideband, FSK, and ASK Need to use AD6620,AD6622, AD6640 and DSP Receive and Transmit P P Receive and Transmit signals in the FM, and AM bandwidth ranges 6 Y Receive and Transmit signals in the CDMA bandwidth range 7 N Transmitter and receiver need to be software programmable 8 P

24 27 October, 2001 MSGC RF Design Project Results Specification Meet Yes (Y) No (N) Partially (P) 1 Transmitting and receiving radio signals at the ISM band range of 900MHz to 920MHz Y 2 Receiver must have a Noise Factor (F) of 4 to 7dB Y 3 Receiver must have a Gain (G) of 34dB Y 4 Intermediate frequency must have a bandwidth of 20 to 28MHz Y 5 Transmitter must have a Gain (G) of 0dB Y

25 Acknowledgments ECE 481/482 Project Team Members: Garett Spalo and Jonathan Barber WMU Department of Electrical and Computer Engineering Michigan Space Grant Consortium Seed and Fellowship Grants BAE Systems donation of a Spectrum Analyzer and Synthesized Signal Generator Dr. Bradley J. Bazuin Advisor/Sponsor Dr. Frank Severance- MSGC Board Member Dr. John Gesink Senior Design Coordinator Dr. S. H. Mousavinezhad Chair of the Department of ECE Dr. I. Abdel-Qader providing support with DSP David F. Florida II, CNE Lab Supervisor 27 October, 2001 MSGC

26 27 October, 2001 MSGC RF Design to Support Software Transceiver for Wireless Communications