IMPROVING THE FREQUENCY STABILITY OF MICROWAVE OSCILLATORS BY UTILIZING THE TEMPERATURE COMPENSATED DIFFERENCE FREQUENCY OF A DUAL-MODE SAPPHIRE LOADED CAVITY RESONATOR

A new difference frequency technique to obtain frequency-temperature compensation using high quality anisotropic dielectric resonators is presented (patent pending). Compensation was demonstrated near room temperature, and between solid and liquid nitrogen temperature (50 to 77 K) by frequency locking two microwave oscillators (Dual-Mode configuration) to orthogonally polarized whispering gallery modes in the same sapphire resonator