60-GHz Bandpass Filter Leverages Standard CMOS Process

With the increasing deMand for broadband multimedia applications, the 60-GHz band has garnered attention for short-range communications. Development has focused on on-chip antennas and filters integrated with low-cost, 60-GHz, integrated-CMOS RF front-end circuitry. At Taiwan's National Cheng Kung University and National University of Tainan, a 60-GHz millimeter-wave on-chip bandpass filter has been designed and implemented using a 0.18-m standard CMOS process. This work was conducted by Chia-Hsieh Liu, Cheng-Ying Hsu, Chu-Yu Chen, and Huey-Ru Chuang.

To design the filter with two transmission zeroes, the researchers used the asymmetric compact microstrip resonator cell structure. The input and output capacitors, which utilize multilayer coupling, are added to create the passband. At a center frequency of 64 GHz, the filter has a 3-dB bandwidth of roughly 15 GHz. The center frequency's measured insertion loss is about 3.9 dB while return loss is better than 10 dB within the passband. See "60-GHz Bandpass Filter with ACMRC Resonator Fabricated Using 0.18-m CMOS Technology," Microwave And Optical Technology Letters, March 2009, p. 597.