1.89 dB insertion-loss UWB BP-filter with three finite transmission zeros using standard 0.18 μm CMOS technology

A low insertion-loss ultra-wideband (UWB) bandpass filter (BP-filter) with three finite transmission zeros by 0.18 m CMOS technology is demonstrated. Low insertion loss is achieved by adopting a 2.34 m-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/S ₂₁) 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 (S ₁₁) 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.