A high frequency bandpass continuous-time filter with automatic frequency and Q-factor tuning

A second order high frequency CMOS bandpass filter with automatic frequency and Q-factor tuning is presented. The frequency tuning is based on the phase-locked-loop technique. A new charge pump circuit and a new quality factor tuning scheme are proposed. The circuit was designed using AMI 0.5 u CMOS process. Simulation results of a bandpass filter working at 100 MHz with expected Q of 20 and 50 are presented.