[摘要]:The analysis and design flow for reduced-size Marchand rat-race hybrids are presented in this paper. A simplified single-to-differential mode is used to analyze the Marchand balun, and the methodology to reduce the size of Marchand balun is developed. The 60-GHz CMOS singly balanced gate mixer and diode mixer using the reduced-size Marchand rat-race hybrid are implemented to verify the design methodology. The monolithic microwave integrated circuit mixers achieve comparable performance with a compact chip size among the reported 60-GHz CMOS mixers.