A D-Band Hybrid-Type CMOS Phase Shifter with Full 360° Phase Coverage

This paper presents a D-band phase shifter fabricated using 65-nm CMOS technology that provides continuous full 360° phase shift. To achieve moderate insertion loss with low DC power, a hybrid-type topology is adopted by combining a 180° reflection-type phase shifter (RTPS) and an active phase inverter (PI). For the reflective load of the RTPS, a pi-type structure with an L-section matching network is employed to achieve a sufficient phase shift range and minimize insertion loss variation. Meanwhile, for the PI, a Gilbert cell structure is adopted to reduce the amplitude and phase error, while transistor sizes are optimized for minimal DC power consumption. The proposed phase shifter exhibits a measured peak gain of -12.1 dB at 147.2 GHz, along with a continuous 360° phase shift. The 3-dB bandwidth is found to be 17.5 GHz within the 136.2 GHz to 153.7 GHz range, within which the RMS amplitude error is maintained below 2 dB, while DC power consumption is only 12 mW.