Development Status of Wideband Millimeter-Wave Receivers for LMT-FINER

TL;DR

The paper reports on the development status of wideband millimeter-wave receivers for the LMT-FINER project, which aims to enhance spectral scanning capabilities for astronomical observations of the early universe.

Contribution

It introduces the design and progress of wideband dual-polarization receivers at 120--210 GHz and 210--360 GHz for the LMT, with significantly increased bandwidth compared to existing systems.

Findings

Development of optics and waveguide components

Progress in low-noise SIS mixers

Enhanced spectral scanning capability

Abstract

Spectroscopic observations of the far-infrared [O III] and [C II] lines present a pathway to explore the mechanisms of the emergence of massive galaxies in the epoch of reionization and beyond, which is one of the most fundamental questions in astronomy. To address this question, the Far-Infrared Nebular Emission Receiver (FINER) project is developing two wideband dual-polarization sideband-separating heterodyne receivers at 120--210 GHz and 210--360 GHz for the Large Millimeter Telescope (LMT) in Mexico. Compared with Atacama Large Millimeter/submillimeter Array (ALMA), LMT provides 40% of ALMA's light-collecting area and a similar atmospheric transmittance, but FINER plans to have an instantaneous intermediate frequency (IF) of 3--21 GHz per sideband per polarization which is five times wider than current ALMA's bandwidth. Therefore, FINER is going to offer cutting-edge spectral scanning capability in the next several years. The project is currently in an active development phase. In this proceeding, the latest development status for FINER, including the optics, wideband waveguide components as well as low-noise superconductor-insulator-superconductor (SIS) mixers is reported.