Improved Vibration Performance in Passive Atomic Frequency Standards by Servo-Loop Control

Abstract : Due to its small size, rapid warm-up, and low power consumption, the rubidium vapor-cell frequency standard unit appears to be the best candidate for most current and near-term tactical frequency standard applications. It's performance under vibration environments, however, remains to be improved. Sources of vibration-induced frequency instabilities in a rubidium frequency standard are reviewed. Demonstrated in this paper is the improved vibration performance of a rubidium frequency standard with the VCXO frequency being tightly servo-controlled to the atomic resonance reference. Technical challenges associated with such a mechanization are briefly discussed. The measured phase spectral density of a rubidium frequency standard with servo-loop bandwidth of approx. 100 Hz is shown. (Author)