A tunable asymmetric notch filter using RFMEMS

In this paper, a single pole single zero asymmetric notch filter using RF micro electromechanical tunable capacitors is presented. The high Q value of the tunable capacitors enables this filter to achieve 25.5dB rejection with less than 1.2dB insertion loss over a 5MHz signal bandwidth. This tunable filter is designed to suppress transmission leakage in the IMT Band I (1.92–1.98GHz) band for handset WCDMA receivers. It also can serve as a component in handset tunable duplexers.