SWRZ090C January 2020 – October 2023 AWR2243
40-MHz OSC CLKOUT Causing Spurs in 2D-FFT Spectrum
AWR2243 ES1.0, ES1.1
Harmonics of 40 MHz from osc-clkout can be coupled onto the synthesizer and can cause low amplitude spurs in the 2D-FFT spectrum. These spurs are at fixed doppler bin, across all range bins.
Workaround 1:
For single chip usecases, where OSC CLKOUT is not used , OSC CLKOUT output can be disabled.
Workaround 2:
For cascade usecase or where OSC clkout is needed in the system, use the chirp dithering capability (idle time, RF start frequency. ADC start time) across the frame to spread the spur across all the Doppler bins and hence avoid false detection.