Dual-mode high gain and high-Q active RF band pass filter

In this paper, a 4^th-order dual-mode active filter was implemented in 0.18μm CMOS process. Center frequency changed from 2.3 GHz to 2.7 GHz in band-select and channel-select modes. Quality factor was 25-100 with 17 dB Gain for band-select mode and 100-500 with 40 dB Gain in channel-select mode. Novel method for tuning Q was designed based on changing NIC factor. Center frequency deviations were compensated for by an analog input. Filter power consumption and input reflection ratio were 6.45 mW and -14 dB, respectively. The main application of this filter was for IEEE 802.11 receivers.