A guide to reduce the phase noise effect in FMCW Radars

One of the most important design issues in FMCW Radars is the detection performance deterioration because of the transmitter phase noise leaked into the receiver. The signals coupled to the receiver path have phase noises uncorrelated with the reference oscillator and the products of these signals generate a corruption in the thermal noise level. There are some internal and external sources increasing the influence of the phase noise. This paper investigates these sources, such as coupling between transmit and receive paths through the radar components, effects of targets having large RCS and surfaces of the radar platform in the radar operation zone generating unwanted echoes and proposes methods like RPC, DLC, windowing and video normalization to reduce the effect of this problem. Experimental results are also presented in this paper.