A push-push oscillator array with very simple coupling circuits using HEMT

A push-push oscillator array with simple coupling circuit is studied. The push-push oscillators are connected via a coupling circuit using a HEMT. The oscillators are synchronized and the output phase difference is controlled by the coupling circuit. The phase difference is changed by the bias voltage of the HEMT. The basic performance of the oscillator array using two push-push oscillators is investigated. It is confirmed that the output phase difference is widely changed by the phase difference of the reflection signals and the phase of the transmission signal of the coupling circuit.