Theoretical verification on the effect of an additional DR in push-push FET DROs

This letter theoretically verifies that a second Dielectric Resonator (DR) placed at the drain port of a push-push FET Dielectric Resonator Oscillator (DRO) can provide compensation for some phase difference/error between the output signals and improve the output power level. The theoretical verification starts from understanding the relationship between output power and phase in a balanced push-push oscillation scheme. The phase compensation causing power improvement is analyzed with an conceptual configuration of the circuit. The effect is confirmed by Advanced Design System (ADS) simulation for the same circuit as that in an earlier experimental report.