CMOS 170 GHz combline bandpass filter

A second-order combline bandpass filter (BPF) in the standard 0.13 μm 1P8M CMOS technology is presented. The miniaturized resonator consists of the on-chip thin-film microstrip transmission line and an interdigital capacitor. The characteristics of the transmission line and the capacitor are theoretically extracted for the filter syntheses. Based on the reported design procedures, a CMOS prototype are implemented and experimentally characterized, showing an insertion-loss of 2.7 dB at 170 GHz with a fractional bandwidth of 10 %. The chip size is 86.5 μm by 45 μm.