A Wideband Millimeter-wave Receiver at 210-350 GHz for LMT-FINER

Haoran Kang; Takafumi Kojima; Takeshi Sakai; Yoichi Tamura; Shun Ishii; Akio Taniguchi; Masato Hagimoto; Masato Kato; Taku Nakajima; Tai Oshima; Sho Masui; Issei Watanabe

arXiv · 2606.25637

A Wideband Millimeter-wave Receiver at 210-350 GHz for LMT-FINER

Haoran Kang·Takafumi Kojima·Takeshi Sakai·Yoichi Tamura·Shun Ishii·Akio Taniguchi·Masato Hagimoto·Masato Kato·Taku Nakajima·Tai Oshima·Sho Masui·Issei Watanabe

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Abstract

The Far-Infrared Nebular Emission Receiver (FINER) project is developing two wideband dual-polarization sideband-separating receivers covering 120-210 GHz and 210-350 GHz to efficiently identify high-redshift galaxy candidates in the early universe. Based on high-critical-current-density superconductor-insulator-superconductor mixer technology originally developed for the ALMA wideband sensitivity upgrade, the FINER receivers are designed to provide an intermediate-frequency bandwidth of 3-21 GHz per sideband and per polarization, approximately five times wider than the current ALMA specifications. After installation on the Large Millimeter Telescope, these receivers are expected to offer highly efficient spectral-scanning capability among (sub)millimeterwave facilities in the northern-hemisphere. This paper reports the initial laboratory characterization of the 210-350 GHz receiver. The measured single sideband receiver noise temperature is approximately 100 K over most of the radio-frequency band. Digital sideband separation was also demonstrated using a wideband spectrometer array (DRS4), achieving an image rejection ratio of around 20 dB in the initial tests. These results represent an important step toward the realization of a wideband spectral-scanning receiver system for FINER.

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Haoran Kang, Takafumi Kojima, Takeshi Sakai, Yoichi Tamura, Shun Ishii, Akio Taniguchi, Masato Hagimoto, Masato Kato, Taku Nakajima, Tai Oshima, Sho Masui, Issei Watanabe. 2026-06-24. A Wideband Millimeter-wave Receiver at 210-350 GHz for LMT-FINER. https://arxiv.org/abs/2606.25637

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