A 270-to-300 GHz LO-Path Phase Shifting Architecture for Sub-mm-wave Phased Arrays

In this paper, a 270 to 300 GHz LO-path phase shifting architecture is presented. It is dedicated to phased array in the sub-mm-wave band for beamforming and beam-steering. The circuit includes a sub-harmonic injection locked oscillator that generates an output signal in the 270-300 GHz band, from an injection signal in the 45 to 50 GHz band that is multiplied by six. To control the phase of the output signal, an analog reflection-type phase shifter is implemented in the 45-50 GHz band, achieving near 60° phase shift in this band, and thus almost 360° in the output band. The circuit was fabricated in a BiCMOS 55 nm technology. It achieves a locking range of 30 GHz with a phase shift variation of 340 ^o ±13 ^o . The power consumption of the whole circuit is 52 mW at 1.2 V voltage supply.