A 4-Path 42.8-to-49.5 GHz LO Generation With Automatic Phase Tuning for 60 GHz Phased-Array Receivers Liang Wu, Alvin Li, and Howard C. Luong , Senior Member , IEEE

Abstract

This paper presents a 4-path LO generation system with automatic phase tuning for 60 GHz phased-array receivers. Each path employs a linear phase-s hift generation chain composed of an injection-locked-oscillator-based p hase shifter cascaded with an injection-locked frequency tripler. The frequency tripler with a proposed locking-range enhan cement technique is employed to relax both the frequency and the phase shifto ft h ep h a s es h i f t e rf o r high linearity and low power. Finally, a novel successive-approxi- mation algorithm is proposed to p erform automatic phase detec- tion and tuning. Fabricated in a 65 n mC M O Sp r o c e s sa n do c c u - p y i n gac o r ea r e ao f1 . 4 2.0 mm², the proposed 4-path LO gener- ation system measures linear phase shift range larger than ±90°, amplitude variation within ±0.4 dB, phase resolution of 22.5°, and maximum phase errors of 22.0° and 1.5° before and after auto- matic phase calibration while drawing a current of 85 mA from a 1-V supply.