1–2 GHz tuning frequency band pass filter with controllable pass band and high stopband rejection

A band pass filter (BPF) for center frequency over a wide frequency span and pass band is presented, which uses an efficient synthesis via two design stages: 1) the transconductance stage and 2) the transimpedance stage. Changing design parameters in the two design stages in 1.8 V 180 nanometer TSMC CMOS process, a BPF for a tuning frequency range of 1.0-2.04 GHz and a controllable pass band of 5.5-51.2 MHz is designed, which achieves a high pass band gain of 45.2-65.1 dB and a stopband rejection of 25 db. The noise figure is kept low to a range of 1.49-5.88 dB when pass band is 12 MHz. It provides a good solution to pre-tune desired signals while reject interfering signals.