10 GHz CMOS hybrid reflective-type phase shifter with enhanced phase shifting range

A new idea is presented to boost the phase shifting range of a reflective-type phase shifter (RTPS) by leveraging the parasitic capacitance; however, without any cost or design overhead. In contrast to the conventional RTPS, where the parasitic capacitance degrades the phase shifting range, a simple position interchange of electronic components leads to an enlarged tuning range. This mechanism is analysed thoroughly and validated by simulation and measurement results. Two RTPSs with different component positions are fabricated in a 65 nm CMOS technology. Grounding inductors leads to a more than 30° phase shifting range than the conventional ones without this arrangement. The S₁₁ is measured at <;-10 dB from 9 to 10.75 GHz and the S₂₁ is -6 dB with <;0.6 dB variations at 10.2 GHz. This technique also provides design insights for phase shifting and tuning range enhancement of general resonant networks.