The Q-Enhanced CMOS Active Bandpass Filter with Two-Stage Self-Calibration

A Q-enhanced 8th order CMOS active bandpass filter is presented employing a novel two-stage self-calibration technique. The proposed active filter shows the better out-band attenuation performance than other reported CMOS active bandpass filters. The proposed calibration method enables the stable filtering operation affected by neither the input power variation nor the strong interference power. It is fabricated using 65 nm CMOS process. The measured 3 dB bandwidth is 54 MHz at 2.37 GHz. The insertion loss is 2.9 dB and the out-band attenuation is 27.5 dB at 15 MHz offset frequency. The performance of the filter remains unchanged for ±5% supply voltage variations. key words: CMOS bandpass filter, calibration, out-band attenuation