A high-Q and wide-dynamic-range 70-MHz CMOS bandpass filter for wireless receivers

Design of a sixth-order CMOS high-Q G(m)-C bandpass filter with automatic tunning for channel selection in wireless receivers is presented. A linearized transconductance (G(m)) cell is designed and optimized for both noise and linearity. The G(m) cells of the biquads and of the tuning circuitry are implemented using unit-G(m) cells for better matching and less power consumption. The filter prototype achieves a measured bandwidth of 200 kHz at 70 MHz (Q = 350). The measured input equivalent noise is 81 nV/root Hz and the IIP3 is -10 dBm, which corresponds to a dynamic range of about 66 dB. At 2.5 V, the total power consumption is 120 mW.