Cryogenic quartz frequency sources: Problems and perspectives

Abstract

This work presents the results of investigation of frequency sources based on cryogenic BAW quartz resonators. Two systems are considered: a passive feedback frequency stabilisation system and a fully cryogenic oscillator. The first approach improves the long-term frequency stability implementing a minimal number of electronic components at liquid helium temperatures. The second one is a BAW oscillator designed for 4K temperatures based on field-effect and bipolar transistors.