Sapphire loaded cavity oscillator with 1:2 divider in dual-mode frequency control loop

This paper develops the novel method of sapphire loaded cavity microwave oscillator frequency stabilization that uses dual-mode sapphire "whispering gallery" resonator (SWGR) oscillator operation and differs from similar approaches by using the output microwave frequency division to form a control signal. In this paper the frequency control is based on two orthogonal "whispering gallery" (WG) modes where the main WGE-mode has twice as much resonant frequency than the auxiliary WGH-mode. A block diagram of the SWGR-based dual-mode oscillator having the 1:2 frequency divider into a microwave section of the temperature control loop incorporates a "usual" microwave SWGR-based oscillator with combined frequency stabilization and an additional temperature control. A microwave section of the last network comprises the directional coupler DC1, the 1:2 frequency divider, the microwave amplifier (MA) working at a half frequency and the SWGR WGH-mode input