Performance of Coupled-Oscillator Arrays With Angle-Modulated Injection Signals

A nonlinear analysis of coupled-oscillator systems under modulated inputs is presented. Angle modulation is introduced to the array by injection locking one of the oscillators to an external modulated reference signal. Envelope transient analysis is used to investigate the effect of the modulation versus scanning angle. Furthermore, a simplified model for the array is provided based on a perturbation of the single-oscillator free-running steady state. In addition, arrays transmitting at the second harmonic are also examined, allowing for extended scanning range. Results are verified by measuring the performance of a fabricated two-element array operating at 4.5 GHz.