AbstractThis paper presents a 100‐GHz phase shifter capable of providing full 360° continuous phase tuning range in 55 nm CMOS technology. The phase shifter is based on reflection‐type phase shifter (RTPS), which has more than 180° phase shift and employs a 0°/180° phase inverter (PI). The amplitude difference between 0°/180° modes of the PI is less than 0.5 dB while the phase imbalance is less than 1° at 90‐100 GHz. The measured insertion loss of the proposed phase shifter for all phase states is 6.1‐10.2 dB at 95 GHz. The chip of our proposed phase shifter occupies an area of 710 × 510 μm2, and the DC power consumption is 20 mW.