A 136-GHz Compact Gain-Boosted Mixer With Wideband Balance-Compensated Baluns for 42-Gbps Communications

This paper presents a compact gain-boosted up-conversion mixer integrated with input active balun in D-band. To simplify the driving stages of power amplifiers and enable large-scale integration in millimeter-wave systems, a proposed gain-boosted technique is introduced. This technique enhances the conversion gain of the mixer without increasing power consumption or footprint, achieved through the synergistic combination of negative resistance compensation (NRC) and current-reuse techniques. Furthermore, a wideband balance compensation technique is utilized at the local oscillator (LO) input, and an active balun is implemented at the intermediate frequency (IF) input, replacing the conventional large-area passive balun. These innovations lead to a more compact high-gain mixer design while achieving high-speed performance. For validation, the proposed up-conversion mixer is fabricated in a 40-nm CMOS. It boasts a total area of 0.15 mm2 ( $0.033~\lambda ^{2}$ ), with a core area of 0.024 mm2 ( $0.0052~\lambda ^{2}$ ). It achieves a measured conversion gain of 4.1 dB at 136 GHz. The measured saturation power is −5 dBm, with a data transmission rate of 42 Gbps, while consuming a power consumption of 10.8 mW only. To the best of our knowledge, this design achieves the highest conversion gain among D-band up-conversion mixers in CMOS technology and represents the smallest footprint among up-conversion mixers integrated with balun in D-band.