V-band 8th harmonic push-push oscillator using microstrip ring resonator

In this paper, the 8th harmonic push-push oscillator is firstly presented. A push-push principle is applied in this oscillator. The proposed push-push oscillator consists of two sub-circuits, a microstrip ring resonator, and an output circuit. A simplified circuit configuration is adopted in the proposed oscillator. The microstrip ring resonator plays two roles of a resonator and a power combiner circuit. This kind of push-push oscillator has the advantages of the easy circuit design, the simple circuit configuration and the miniaturization of the circuit size. Using the effective circuit configuration of the output circuit, a desired 8th harmonic signal is successfully enhanced. This push-push oscillator achieves high quality V-band millimeter wave oscillation using inexpensively available X-band HEMTs. The measured output power of -12 dBm at the frequency of 51 GHz is obtained with the phase noise of -94 dBc/Hz at the offset frequency of 1 MHz.