A 60-GHz Millimeter-wave CMOS Marchand Balun

Abstract

A novel 60-GHz wideband Marchand balun fabricated with a standard 0.18 μm 6-metal-layer CMOS process for millimeter-wave applications is presented. A technique for achieving good balance with the fourth metal layer microstrip conductor is used in the designed Marchand balun. The fabricated CMOS balun uses multilayer coupling with the top two layers. An output matching network is added to improve the output return loss. The measured amplitude imbalance was about ± 1.5 dB from 25 to 65 GHz , over the 89% operating frequency band.