A CMOS 4.35-mW +22-dBm IIP3 Continuously Tunable Channel Select Filter for WLAN/WiMAX Receivers Mostafa Savadi Oskooei , Student Member , IEEE

Abstract

A low-power high linearity CMOS G -C channel select filter for WLAN/WiMAX receivers in 90-nm CMOS tech- nology is presented. To reduce power consumption a biquad cell with simple architecture is used. A simple but ef ficient technique is also proposed to improve the linearity of the filter without increasing its power consumption. Coarse and fine tuning tech- niques are used to tune the cutoff frequency of the sixth-order Butterworth low-pass filter from 8.1 MHz to 13.5 MHz suitable f o rW L A Na n dW i M A Xa p p l i c a t i o n s .T h em e a s u r e m e n tr e s u l t s show an in-band IIP3 of 22 dBm, an HD3 better than 40 dB at 470 mV input signal amplitude, and an input referred noise of 75 nV/ Hz at a power consumption of 4.35 mW from a 1-V supply. The differential filter occupies a chip area of 0.239 mm excluding pads.