A CMOS Voltage Controlled Continuous Phase Shifter With Active Loss Compensation

A voltage controlled RF linear phase shifter (VPS) on CMOS process is proposed and developed to address insertion loss variation over a control range, linearity of phase control, and the size of implementation. A new compensation method for a transmission line phase shifter is introduced. By compensating loss associated with lumped elements in a transmission line, the measured CMOS VPS achieves minimum 2.8 dB insertion loss and +/- 0.6 dB insertion loss variation over 120 degrees phase shift at 1.95 GHz, consuming 4 mA from 1.8 V supply. The size of the phase shifter is 850 mu m x 440 mu m without pads. The measured input P1dB of the design is higher than 4 dBm. To the best of author's knowledge, the demonstrated phase shifter achieves one of the best performances published in a CMOS process without using active inductors.