Main features of space rubidium atomic frequency standard for BeiDou satellites
Wuhan Institute of Physics and Mathematics (WIPM) has been developing the space rubidium atomic frequency standard (RAFS) for BeiDou navigation satellite system since the late of 1990's. Design of the RAFS aims to realize high stability, small size, long lifetime, high reliability and space environmental adaptability. The physics package was designed in SFT scheme. A slotted tube cavity with small size and TE011 resonant mode was used to construct the cavity-cell assembly, and an argon lamp with long lifetime was used as the pumping source. The microwave chain includes a 10MHz VCXO, a 5.3125MHz synthesizer, a ×9 RF multiplier and a ×76 SRD multiplier. Electronic circuits were designed by using analog circuitry to minimize the risk of element failure in space. The day stability of the space RAFS's developed for BeiDou regional system distributes within 2~5×10-14. To meet the needs of BeiDou global system, design of the RAFS has been improved further. A slotted tube cavity with larger size and better resonant mode was used, the argon lamp was substituted with a filtered xenon lamp, and the phase noise of microwave chain was depressed further. A prototype of new generation space RAFS was built recently. Preliminary test showed that the day stability of the prototype has reached 3×10-15.
A miniaturized microwave resonator for rubidium frequency standards
Summary form only given. A new type of miniaturized resonator based on the magnetron resonator theory has been developed. The resonator is of small size and high quality factor, and has been used in a rubidium frequency standard.
RF-Interrogated End-State Chip-Scale Atomic Clock
Abstract : A chip-scale atomic clock implemented with end-state physics has been fabricated and characterized. Batch-fabricated components were specifically designed and developed to enable integration within a small form-factor package. The full physics package, implemented with CW VCSEL optical pump, direct end-state hyperfine RF and Zeeman interrogation for magnetic field stabilization, was demonstrated within a 4 cm3 volume, consuming 25 mW of power, and exhibiting an Allan deviation stability. In addition, end-state signal contrast exceeded 40% from millimeter-scale vapor cells with buffer-gas pressures exceeding 2.5 atmospheres, demonstrating the route to submillimeter vapor-cells within high-performance CSACs for high shock/vibration environments.