Unformatted Digital Fiber-Optic Data Transmission for Radio Astronomy Front-Ends

TL;DR

This paper presents a compact, integrated radio astronomy receiver front-end with a novel optical fiber digital data link that simplifies design, reduces interference, and enhances stability by eliminating front-end formatting.

Contribution

Introduction of a digital data link over optical fiber that requires no front-end formatting, reducing complexity, size, power, and RFI in radio telescope systems.

Findings

Reduced complexity and size of the receiver front-end.

Lower power consumption and RFI leakage.

Maintained high stability and precision in data transmission.

Abstract

We report on the development of a prototype integrated receiver front-end that combines all conversions from RF to baseband, from analog to digital, and from copper to fiber into one compact assembly, with the necessary gain and stability suitable for radio astronomy applications. The emphasis in this article is on a novel digital data link over optical fiber which requires no formatting in the front-end, greatly reducing the complexity, bulk, and power consumption of digital electronics inside the antenna, facilitating its integration with the analog components, and minimizing the self-generated radio-frequency interference (RFI) which could leak into the signal path. Management of the serial data link is performed entirely in the back-end based on the statistical properties of signals with a strong random noise component. In this way, the full benefits of precision and stability afforded by conventional digital data transmission are realized with far less overhead at the focal plane of a radio telescope.