RF Des esign for GNSS rec ecei eiver ers Kevin Parkinson - PowerPoint PPT Presentation

RF Des esign for GNSS rec ecei eiver ers Kevin Parkinson

Contents • The KEA GNSS receiver • Receiver architecture • RF Down-converters • Design Challenges • Results | 2 IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Kea V4.1SB Receiver Module • Credit card sized • SmartFusion2 SOC – Large flash based FPGA with 50k or 80k logic elements and enhanced SEU immunity – Powerful 166 MHz ARM Cortex M3 processor • 512 Mb of SECDED LPDDR SDRAM • 8 MB of serial Flash • 8 kB of FRAM (ferromagnetic RAM) • CMOS RF ASIC capable of L1/E1 operation • Super-capacitor powered RTC • Support for disciplined VC-TCXO and reference frequency output • USB2 interface for debugging and data-capture | 3 IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Typical GNSS Receiver IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

RF Down converter ASIC IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Design challenges Paramater Affected performance Noise figure System sensitivity & Signal-to-noise ratio Frequency plan Image rejection & Interference rejection IF Topology Noise, Imgage rejection & Intermodulation distortion LNA type Signal-to-noise ratio & Intermodulation distortion Mixer type VCO leakage, Signal-to-noise ratio & Intermodulation distortion VCO leakage Local interference & Intermodulation distortion IF bandwidth Image rejection, Selectivity & Interference rejection VCO Phase noise Signal-to-noise ratio Intermodulation Signal-to-noise ratio & Dynamic range Dynamic range Sensitivity & Interference tolerance Power consumption Signal-to-noise ratio & Dynamic range Cross modulation Signal-to-noise ratio & Dynamic range Linearity Signal-to-noise ratio & Interference tolerance IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Single frequency ASIC • 4 to 24MHz BW • 60 dB AGC range IF MIXER MAG 2 Bit RF • 2 Bit ADC IN A/D SIGN LNA IF AMP AGC • 75dB Gain Synthesiser REF /2 vco and PLL INPUT • 3.9dB NF SPI Control • 4 or 12MHz IF SPI • 32MHz sample IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Dual Frequency ASIC • 32 MHz BW • 60 dB AGC range • 3 bit ADC • 75 db Gain • 6.9 db NF • 16 MHz IF • 32 MHz sample IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Single frequency results Parameter L5/E5a L2 L1 Frequency 1176.45 MHz 1227.6 MHz 1575.42 MHz NF 3.9dB 4dB 7dB Gain 75dB 74dB 75dB VSWR In 1.5:1 1.45:1 1.52:1 Power 0.6W 0.6W 0.6W IP3 -17dB -17.5dB -18dB PN 100KHz -107dB/Hz -110dB/Hz -117dB/Hz IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Dual frequency results Parameter L5/E5a L2 L1 Frequency 1176.45 MHz 1227.6 MHz 1575.42 MHz NF 6.9dB 6.8dB 7dB Gain 75dB 74dB 75dB VSWR In 1.5:1 1.5:1 1.5:1 Power 1W 1W 1W IP3 -17dB -17.5dB -18dB PN 100KHz -94dB/Hz -95dB/Hz -97dB/Hz IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

L1/E1 IF out IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

L5/E5 IF out IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney

Thankyou | 1 IG NSS 201 6, 6-8 Dec 201 6, UNSW,Sydney 3