A 38-to 40-GHz Current-Reused Active Phase Shifter Based on the Coupled Resonator

A 38- to 40-GHz current-reused active phase shifter based on a coupled resonator is proposed. The coupled resonator is used to increase the phase-shifting range and reduce the gain variation along with the phase-shifting value. The digital controlled artificial dielectric transmission lines are used instead of varactors to achieve high quality and directly digital control, and a current reuse technique is employed to reduce the power consumption. Implemented in 65-nm CMOS, the phase shifter occupies a chip area of 0.16 mm(2) without pads and consumes a 6.6 mA current from a 1.0 V power supply. Measured results show that the gain variation of the phase shifter is less than 1 dB over 38-40 GHz while achieving the 90. phase-shifting range.