A new Q-enhancement architecture for SAW-less communication receiver in 65-nm CMOS

A 2.5 V second order RF bandpass filter is presented. A new Q-enhancement structure stacked on a LNA is fabricated in a 65-nm CMOS process with a die area of 1.1 mm × 1.1 mm. The frequency range is adjustable in a 25% range from 1.7 GHz to 2.2 GHz while the Q is adjustable up to 50. Q and the center frequency are adjusted by binary weighted switchable capacitors. The filter draws 42 mA including the buffers from a 2.5 V supply and has an input referred out-of-band 1-dB compression point of 0 dBm. The measured in-band NF is between 5.4 and 6.2 dB.