1.89 dB insertion-loss UWB BP-filter with three finite transmission zeros using standard 0.18 [micro sign]m CMOS technology

Abstract

A low insertion-loss ultra-wideband (UWB) bandpass filter (BP-filter) with three finite transmission zeros by 0.18 µm CMOS technology is demonstrated. Low insertion loss is achieved by adopting a 2.34 µm-thick microstrip-line with an optimised ground-plane pattern as the needed inductors to minimise the metal and substrate loss. This filter achieved insertion loss (1/S21) lower than 3 dB over the frequency range 3.9–9.4 GHz, stop-band rejection better than 20 dB over the frequency range 0–2.1 and 13.5–42.2 GHz, and input return loss (S11) better than −10 dB over the frequency range 3.1–12.8 GHz. Minimum insertion loss was 1.89 dB at 6.8 GHz. This is believed to be the best result ever reported for a CMOS BP-filter with operation frequencies higher than 3 GHz.