86 to 94GHzlow lossCMOSbalanced resistive mixer using an asymmetric broadside coupler and delay lines

Abstract

An 86 to 94 GHz balanced resistive mixer (BRM) is presented using a 65 nm complementary metal-oxidesemiconductor (CMOS) process. We minimize parasitic losses which are serious at high frequency by adopting symmetric transistor structures. A low loss 180 hybrid is implemented using an asymmetric broadside coupler and delay lines. This allows low-loss implementation of 86 to 94 GHz BRMs, which represent a conversion loss of 10.3 to 13.0 dB from 86 to 94 GHz of RF frequencies. The balanced designs produce LO-to-RF isolations of 32 to 36 dB from 87 to 93 GHz. The proposed CMOS BRM shows competitive results when compared to GaAs-or InP-based balanced resistive mixers having moderate LO power requirements.