CCAT-prime: RFSoC Based Readout for Frequency Multiplexed Kinetic Inductance Detectors

TL;DR

This paper presents a new RFSoC-based microwave frequency multiplexed readout system designed for large arrays of kinetic inductance detectors in the Prime-Cam instrument, improving size, power, and bandwidth efficiency.

Contribution

It introduces a baseline firmware and architecture for RF multiplexed readout on RFSoC, capable of reading 2000 detectors with enhanced performance metrics.

Findings

System can read out four RF networks simultaneously.

Preliminary phase noise and dynamic range measurements are promising.

Design meets the specific requirements of the Prime-Cam instrument.

Abstract

The Prime-Cam instrument on the Fred Young Submillimeter Telescope (FYST) is expected to be the largest deployment of millimeter and submillimeter sensitive kinetic inductance detectors to date. To read out these arrays efficiently, a microwave frequency multiplexed readout has been designed to run on the Xilinx Radio Frequency System on a Chip (RFSoC). The RFSoC has dramatically improved every category of size, weight, power, cost, and bandwidth over the previous generation readout systems. We describe a baseline firmware design which can read out four independent RF networks each with 500 MHz of bandwidth and 1000 detectors for ~30 W. The overall readout architecture is a combination of hardware, gateware/firmware, software, and network design. The requirements of the readout are driven by the 850 GHz instrument module of the 7-module Prime-Cam instrument. These requirements along with other constraints which have led to critical design choices are highlighted. Preliminary measurements of the system phase noise and dynamic range are presented.