Tunable Antenna-Coupled Intersubband Terahertz (TACIT) Mixers: The Quantum Limit Without the Quantum Liquid

TL;DR

This paper proposes TACIT heterodyne mixers for 1-5 THz that operate at higher temperatures with near-quantum-limited noise performance, reducing cooling requirements for Terahertz detection.

Contribution

It introduces a novel semiconductor-based tunable antenna-coupled intersubband mixer design capable of near-quantum-limited noise at elevated temperatures.

Findings

Predicted single-sideband noise temperatures of a few hundred K.

IF bandwidth greater than 10 GHz.

Operation at lattice temperatures above 20 K with minimal LO power.

Abstract

At present, nearly quantum-limited heterodyne receivers for Terahertz (THz) frequencies require cooling to temperatures below 4K. We are working to build semiconductor-based "tunable antenna-coupled intersubband terahertz" (TACIT) heterodyne mixers for 1-5 THz. We predict that they can achieve single-sideband noise temperatures of a few hundred K with intermediate frequency (IF) bandwidth >10 GHz, while operating at lattice temperatures >20 K and requiring local oscillator (LO) power ~ 1 $\mu$W.