The design and fabrication of a compact low phase noise dielectric cavity resonator oscillator

This paper presents the design and fabrication of a compact low phase-noise × band voltage controlled oscillator (VCO). The prototype is designed based on closed loop topology and includes GaAs PHEMT MMIC, a novel shielded high dielectric cavity resonator, microstrip low-pass filter and phase shifter network. To achieve low phase noise oscillation, a compact two port high dielectric cavity resonator is designed, and properly embedded into the feedback Loop as a frequency stabilization element. The tuning system includes varactor diodes lightly coupled into the closed loop circuit and allows 50 MHz tunability across the desired bandwidth. A Prototype design has been built to verify the analysis. The measurement results show the completed assembly is 6mm × 6mm × 1.5mm with 11.4 dBm output power and -94 dBc/Hz phase noise at 10 kHz offset.