Energy circulation quadrature LC-VCO

Abstract

An energy circulation technique is shown to unite an even number of oscillation tanks to form an integrated oscillator. It reduces phase noise and boosts the figure-of-merit beyond that which is achievable by a differential VCO while generating quadrature phase. The measured phase noise of a two-way configuration at 1 MHz offset is -132.6 dBc/Hz while drawing 27.7 mW from a 1.8 V supply. In simulation, the four-way configuration further reduces the phase noise by 3 dBc/Hz. Techniques for correcting the +/-90/spl deg/ phase ambiguity problem and I/Q phase mismatch are also presented.