Appendix E: Transmitter Noise Leakage
The problem of transmit-receive noise leakage is known as one of the most severe problems facing the FMCW radar designer. The FM sidebands at a deviation of ωm like AM (amplitude modulation) noise sidebands at the same frequency give rise to noise also, but only at an IF of ωm. There is thus a simple relationship between the transmitter's noise spectra and the spectrum of the detected noise in the receiver's IF. Moreover, in the case where the frequency deviation is independent of frequency, that is, it is the same at all frequencies of interest, then it will be shown that the detected noise is the same at all IF frequencies, which is the same as the case for white AM noise. This derivation is based on the paper by Stove.