Reference Signal Synthesized from a Cryogenic Sapphire Oscillator Improved by Power Control Servo

摘要

Improvements in the frequency stability of a reference signal synthesized from a cryogenic sapphire oscillator (CSO) have been realized. This has been achieved by a power control servo with active Pound frequency stabilization in the loop oscillator based on a high Q-factor cryogenic sapphire resonator with a loaded Q-factor of 5 x 10~8 at 10.812 GHz and operating at a temperature of 6 K. The reference signal of 100 MHz was synthesized from the 10.812 GHz oscillation frequency. When compared with a 100 MHz hydrogen maser signal, the 100 MHz reference exhibited a fractional frequency stability of 5.6 x 10~(-15) at an integration time of 510 s, which is approximately two times better than that without power servo control.