A CMOS coupled nonlinear oscillator array

This paper details an experimental nonlinear beamforming array fabricated in a CMOS process. The unit cell oscillator is a nonlinear second order circuit, which demonstrates self-sustaining oscillation. In this paper experimental results from a test oscillator and a linearly coupled array of oscillators are reported. The circuit equations of motion are shown to be equivalent to the van der Pol oscillator, from which a weakly nonlinear phase-amplitude model is derived. This model forms a basis of understanding for the experimental nonlinear beamforming array.