Leakage Phase Noise Mitigation for Monostatic FMCW Radar Sensors Using Carrier Transmission

One common problem of frequency modulated continuous wave radar is leakage from the transmitter to the receiver. The leakage power is orders of magnitude larger than the target return power and appears as a very strong signal in the first few range bins. Additionally, the residual phase noise density of the local oscillator occurs around the leakage signal, which often raises the noise floor and limits the dynamic range of a radar system at the close proximity of the sensor. In this paper a novel system concept that cancels the phase noise around the dominating leakage path is proposed, mathematically derived, and proven by radar measurements with a radar demonstrator at 77 GHz.