60 GHz active phase shifter using an optimized quadrature all-pass network in 45nm CMOS

This paper presents a differential 60 GHz phase shifter based on a vector modulator approach. The inclusion of a series resistor in the all-pass I/Q greatly reduces the effect of the capacitance loading change vs. bias current and results in a wideband phase shifter. The phase shifter achieves a gain of −6+/−2 dB with IP1dB of 0–3dBm at 55GHz, and an rms phase error of <11° at 40–70GHz (PDC=23 mW, VDD=1.5V). This is the first demonstration of a wideband 45nm 60 GHz phase shifter.