Geometric Analysis and Systematic Design of a Reflective-Type Phase Shifter With Full 360° Phase Shift Range and Minimal Loss Variation

In this article, a geometric method, along with the concept of the reference circle, is proposed for the analysis of reflective-type phase shifter (RTPS). Comprehensive analyses of popular reflective loads, including capacitive load (CL), resonated load (RL), and π-type load, are presented, revealing their limitations. The triple-resonating load technique is proposed to accomplish a full 360° phase shift range and suppress the loss variation. Further, a systematic design methodology for the RTPS using triple-resonating load is developed. Fabricated in 65-nm CMOS technology, the proposed RTPS occupies a core chip area of 0.076 μm
²
. It achieves the first-ever 379° phase shift range at 29 GHz with only one control voltage. With dual-voltage control, a full 360° phase shift range with 8.3 ± 0.2 dB insertion loss is achieved. For both control methods, the return loss is better than 22.8 dB for all phase shift states.