Analysis of wide-IF-band 65 nm-CMOS mixer for 77–110 GHz radio-astronomical receiver design

This manuscript presents the design of a W-band receiver in which an radio frequency-low noise amplifier (RF-LNA), a wideband mixer, intermediate frequency (IF) amplification, a local oscillator frequency (LO) tripler and a driving amplifier are all integrated into one single chip of 1050 × 820 μm². To effectively extend the mixer's IF bandwidth while retaining its conversion gain, impacts of the mixing transistor's drain bias and output loading impedance are explored using a dual-modulation conversion-matrix method, which allows both the LO-induced transconductance modulation and channel-conductance modulation to be considered simultaneously. It is shown that, by merging the input capacitance of the IF amplifier into a high-impedance artificial transmission line, an actively biased mixer can have constant conversion gain over broad bandwidth. A 77–110 GHz 65 nm-complementary metal-oxide-semiconductor (CMOS) receiver with 33 GHz IF bandwidth is then designed and measured. Its conversion gain and noise figure are 10 and 20 dB, respectively, and the input-referred P1 dB is −15 dBm; the overall power consumption is 330 mW under 1.3 V drain bias.