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