1.15 GHz image rejection filter with 45 dB image rejection ratio and 8.4 mW DC power in 90 nm CMOS

摘要

A 1.15 GHz image rejection filter in 90 nm CMOS is presented. It consists of two band-pass filter stages and one band-stop filter stage, with the Q-enhancing and frequency stagger-tuning techniques to compensate the loss of low quality factor on-chip passive components and maintain enough bandwidth, respectively. The presented filter has been integrated in one K-band dual down-conversion super-heterodyne receiver and achieves 45 dB image rejection ratio at 140 MHz offset with 22 MHz signal bandwidth. The DC power consumption is 8.4 mW.