One‐decibel insertion loss 1–14.3 GHz ultrawideband bandpass filter using standard 0.18 μm CMOS technology

A low insertion loss ultrawideband (UWB) bandpass filter (BP filter) with two finite transmission zeros (f z1 and f z2 ) at high‐frequency stopband by 0.18 μm CMOS technology was demonstrated. f z1 (the lower frequency one) and f z2 can be tuned individually by the shunt branch (L 2 , R s2 , C 3 , and C 4 + C p2 ) and the series inductor (L 1 , R s1 , and C p1 ), respectively. The microstrip line interconnection lines as well as the spiral inductors were implemented by the 2.34‐μm‐thick topmost metal (M 6 ) to minimize the resistive loss. This filter achieved insertion loss (1/S 21 ) lower than 3 dB for frequencies 1–14.3 GHz, stopband rejection better than 20 dB for frequencies higher than 20.4 GHz, and input return loss (S 11 ) better than −10 dB for frequencies 2.4–16.4 GHz. The minimum insertion loss was 1 dB at 4.2 GHz. To our knowledge, this is one of the best results ever reported for a CMOS UWB BP filter in the literature. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1044–1047, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26743