A multi-band RF CMOS LC bandpass filter with continuous frequency tuning design

In this paper, a 2nd order tunable RF CMOS LC bandpass filter with the on-chip inductor is presented. Q-enhancement and tuning are also considered. The Q-tuning is implemented through an adjustable negative conductance generator circuit. The simulated results show that the center frequency of the filter using a 0.18µm CMOS process can be operated from 1.90GHz to 2.42GHz frequency band under 3.3V supply by a set of capacitor array and the varactors that achieve the coarse and exact tuning respectively