Square Kilometer Array Telescope - Precision Reference Frequency Synchronisation via 1f-2f Dissemination

TL;DR

This paper presents a novel 1f-2f dissemination scheme for ultra-high precision frequency synchronization across multiple antennas in the SKA, achieving phase noise performance matching the hydrogen maser standard.

Contribution

It introduces a client-site phase noise compensation method for frequency reference dissemination suitable for large-scale radio telescope arrays.

Findings

Disseminated 100 MHz reference signal maintains hydrogen maser phase noise levels.

System successfully synchronized two remote sites with SKA-compliant precision.

Star-shaped topology enables scalable synchronization for SKA antennas.

Abstract

The Square Kilometer Array (SKA) is an international effort to build the world's largest radio telescope, with one square kilometer collecting area. Besides its ambitious scientific objectives, such as probing the cosmic dawn and cradle of life, SKA also demands several revolutionary technological breakthroughs, with ultra-high precision synchronisation of the frequency references for thousands of antennas being one of them. In this report, aimed at applications to SKA, we demonstrate a frequency reference synchronization and dissemination scheme with the phase noise compensation function placed at the client site. Hence, one central hub can be linked to a large number of client sites, forming a star-shaped topology. As a performance test, the 100 MHz reference signal from a Hydrogen maser clock is disseminated and recovered at two remote sites. Phase noise characteristics of the recovered reference frequency signal coincides with that of the hydrogen-maser source and satisfies SKA requirement.