A D-Band High-Linearity Down-Conversion Mixer for 6G Wireless Communications

A D-band down-conversion mixer with high-linearity for 6G wireless communications is presented in 28-nm CMOS technology. The mixer operates at the radio frequency (RF) of 130-150 GHz and intermediate frequency (IF) of 11-15 GHz. The mixer is based on Gilbert active mixer to obtain a high conversion gain and consists of a transconductance (GM) stage, a switch (SW) stage, and a local oscillator (LO) driving stage. The GM and SW stages are inductively coupled with a transformer, which results in high-linearity by providing high drain-to-source voltage to the SW stage. For the output of the mixer, a transformer optimized for high conversion gain and linearity based on load-pull simulation is used to obtain the conversion gain of 4.4 dB and output third-order intercept point (OIP3) of 11.31 dBm. The implemented down-conversion mixer consumes 36 mW with 0.9 V of supply voltage, and its area including pads is 0.3 mm ^{2} .