CMOS bandpass filters for 77 GHz automotive radar systems

This article presents a systematic design and measurement of narrow and wide bandpass filters at 77 GHz in a 0.18-μm CMOS technology. Various bandwidths from 10 to 50% are realized using a parallel coupled line topology in a thin film microstrip configuration. The relationship between the insertion loss and the 3-dB bandwidth of the filters is experimentally determined for this technology. The result is also compared with theoretical prediction.