Self-Adaptive Short-Range Leakage Canceler for Automotive FMCW Radar Transceivers

Frequency modulated continuous wave (FMCW) radar sensors are key enablers for many of today's driver assistance systems. For several reasons, these sensors are often placed right behind the bodywork of the car. This, however, causes an undesired signal reflection, the so-called short-range (SR) leakage. Together with the phase noise (PN) contained within the radar transmit signal, the SR leakage may increase the overall system noise floor, thus degrading the detection sensitivity. In previous work, we proposed a cancelation concept for the SR leakage. Therein, however, the SR leakage was considered to be a static object reflection with known reflection parameters. In this work, we extend the proposed SR leakage canceler, and present a fully self-adaptive version of it. We prove our concept based on measurement results from a hardware prototype, wherein the proposed adaptive SR leakage cancelation is carried out in real-time on a field programmable gate array (FPGA).