A 3.5 GHz low insertion loss variation CMOS phase shifter

A 3.5 GHz low insertion loss variation phase shifter has been designed and fabricated on standard 0.18-μm CMOS process. To achieve over 360° continuously phase tuning range, the phase shifter consists of a switch type phase shifter (STPS) and a reflection type phase shifter (RTPS). The phase-invertible variable attenuator (PIVA) topology which can provide two states with 180° phase-shift while maintaining low amplitude imbalance is adopted. The RTPS provides over 189° continuously phase tuning. The experimental results show that the 3.5 GHz phase shifter demonstrates over 360° continuously phase tuning range with low insertion loss variation of 1 dB at 3.5 GHz. The maximum insertion loss is 13.5 dB at 3.5 GHz and the dc consumption is zero. The chip size is 1.08 mm × 0.82 mm.