Compact Tunable Bandpass Filter for RF and Microwave Applications

In this paper, a fully CMOS bandpass filter with wide tunable frequency band suitable for radiofrequency (RF) and microwave applications is presented. The circuit has been realized in 130 nm CMOS technology using differential cascode grounded active inductor in place of spiral inductors, significantly improving the overall performances of the filter. The proposed design achieves a tuning range about 300% around 2 GHz indicating a very high slope factor. The filter draws between 3.68 and 6.44 mW from 1 V power supply, while attaining a maximum voltage gain of 33.45 dB at 1.84 GHz, a quality factor of 76.66 and a noise figure of 14.93 dB. It achieves a 1-dB compression point of −1.5 dBm and a surface area of only $(427\text{x}576)\mu \text{m}^{2}$.