A 7.1-mW $K/K_{a}$ -Band Mixer With Configurable Bondwire Resonators in 65-nm CMOS

A low-power (LP) K/Ka-band mixer with configurable capability is proposed in this paper. The mixer integrates a broadband transconductor stage, bondwire resonators, a broadband local oscillator balun, and a broadband switching stage. The bondwire resonators not only work as a balun for single-ended to differential conversion between the transconductor stage and the switching stage, but they can also be configured to have two or three resonators by controlling the number of bonding bondwires during the chip packaging process. These two and three resonators intentionally designed to have weak and strong magnetic couplings with each other, enable the mixer to exhibit narrowband and broadband frequency responses, respectively. Realized in a 65-nm LP CMOS technology, the mixers configured to have two and three resonators that show the measured conversion gains of 17.2 and 15.5 dB while giving 3- and 5-dB bandwidths from 22.5 to 28.5 and 21.5 to 32.5 GHz, respectively. The measured input third-order intercept points, noise figures, and port-to-port isolations of the mixers with two and three resonators are better than -2.7 and -1.9 dBm, 11.2 and 11 dB, and 25.6 and 25.7 dB, within the bandwidths, respectively. The mixer only consumes 7.1 mW from a 1.2-V supply.