An oscillator array using positive feedback type push-push oscillators and directional phase shifters

An oscillator array using a positive feedback type Push-Push oscillator is presented. The coupling circuit used for the oscillator array is a directional phase shifter consists of a directional coupler and a reflection type phase shifter using a Ronde coupler. An oscillating signal in the feedback loop of Push-Push oscillator is injected into that of the adjacent oscillator via the coupling circuit. The Push-Push oscillators are synchronized and the phase difference between the output signals is controlled by the injection signal. Performance of two-element and three-element oscillator arrays are demonstrated and compared. In the three elements oscillator array, phase shift about 140 degrees is obtained between the output signals of adjacent oscillators in Ku band.