A 60GHz digitally controlled 4-bit phase shifter with 6-ps group delay deviation

A 57-64 GHz 4-bit switch type phase shifter with low group delay deviation and low loss flatness using 90nm low power CMOS technology is presented in this paper. The proposed switched delay networks are using transmission lines to avoid process variation of small-size capacitors. It is also measured with excellent insertion loss flatness of ±0.8dB for a specific phase shifting state, across 57-64 GHz. For all 16 states, the insertion loss is 12.5 ± 2dB including pad loss at 60 GHz and the return loss is >10dB over 57-64 GHz. The total chip size is 0.28 mm ², excluding pads with 0-mW dc power consumption. The phase shifter has low group-delay deviation (phase-distortion) of +/6 ps from 57-63 GHz. To the best of our knowledge, this phase shifter presents the best FoM among V-band phase shifters.