ELISA: a cryocooled 10 GHz oscillator with 10-15 frequency stability

TL;DR

This paper presents the design and validation of a cryocooled 10 GHz sapphire oscillator achieving unprecedented fractional frequency stability of 3x10^-15 for deep space communication, demonstrating the feasibility of ultra-stable cryogenic oscillators.

Contribution

It introduces a novel cryogenic sapphire oscillator with record stability, validated through breadboarding and testing in an autonomous cryocooler, suitable for space applications.

Findings

Achieved fractional frequency stability of 3x10^-15 between 1 s and 1,000 s

Validated the design of sapphire resonator and cryocooler system

Demonstrated lowest fractional frequency instability with cryocoolers to date

Abstract

This article reports the design, the breadboarding and the validation of an ultra-stable Cryogenic Sapphire Oscillator operated in an autonomous cryocooler. The objective of this project was to demonstrate the feasibility of a frequency stability of 3x10-15 between 1 s and 1,000 s for the European Space Agency deep space stations. This represents the lowest fractional frequency instability ever achieved with cryocoolers. The preliminary results presented in this paper validate the design we adopted for the sapphire resonator, the cold source and the oscillator loop.