A Small High-Temperature Rubidium Frequency Standard

The rubidium frequency standard is widely used in many fields because of its small size, reliable performance, and economical application. However, the current mainstream commercial rubidium frequency standard has a working temperature range of −45 ℃ to +70 ℃, which cannot meet the long-term use requirements of high temperature environments above +70 ℃.The operating temperature of the physical package of the rubidium frequency standard is improved by changing the parameters such as the type of buffer gas, gas pressure, and type of rubidium filling in the rubidium bulb and rubidium absorption cell. The operating temperature range of the small high-temperature rubidium frequency standard is expanded to −45 ℃ ~ +80 ℃, and the volume is compressed to 100 mm × 100 mm × 25 mm. The test data shows that the frequency stability of the small high-temperature rubidium frequency standard is better than 3E-11/\(\sqrt{\uptau }\) (τ:1 s ~ 1000 s), the temperature frequency characteristic is better than 5E-9 in the range of −45 ℃ ~ +80 ℃, and it can remain locked at the ambient temperature of +85 ℃.