A Millimeter-Wave Fully Integrated Passive Reflection-Type Phase Shifter With Transformer-Based Multi-Resonance Loads for 360° Phase Shifting

This paper presents a millimeter-wave fully differential transformer-based passive reflection-type phase shifter (RTPS) capable of performing full span 360° continuous phase shift from 58 to 64 GHz. It consists of two transformerbased 90° couplers and two transformer-based multi-resonance reflective loads to provide 360° phase shift with low loss and ultra-compact chip size. Our proof-of-concept design is implemented in a standard 130-nm BiCMOS process with a core area of 480 μm × 340 μm. It achieves a wide phase shifting range of 367° and a low insertion loss IL (3.7 dB <; |IL| <; 10.2 dB) at 62 GHz and maintains a full span 360° phase shifting range from 58 to 64 GHz. Moreover, it supports 360° phase shifting with a constant IL, i.e., |IL| = 10, 11, 12 dB, at an IL variation of less than 0.74 dB at 62 GHz. To the best of our knowledge, this design achieves a first-ever full span 360° phase shifting (up to 367°), the lowest IL, the smallest IL variation, and the best figure-of-merit of 37.1°/dB among reported 60 GHz fully integrated RTPS in silicon.