Planar realization of low phase noise 15/30 GHz oscillator/doubler using surface mount transistors

This paper presents the application of a novel high-Q planar waveguide resonator for microwave oscillator design. The waveguide cavity is made in printed-circuit-board process, first using a routed cut followed by a plated viathrough-hole. Measurements show that the oscillator stabilized by the resonator delivers an output power of 14 dBm at 15 GHz and a phase noise of -98 dBc/Hz at 100 kHz offset from the carrier, under 5-V single bias. Experiments indicate the predominance of the waveguide resonator by a 13-dB phase noise improvement at 100 kHz offset against the microstrip oscillator.