Cryogenic Receiver Frontends of High Sensitivity for Terahertz Communication Applications

This paper overviews our latest achievement in developing high-sensitivity cryogenic heterodyne receivers for terahertz (THz) wireless communication system applications. As typical representatives, one 220-GHz antenna-coupled cryogenic Schottky receiver and one 340-GHz high-temperature superconducting Josephson-junction heterodyne receiver, are both discussed in detail. Both cryogenic receivers have exhibited the superior performance, with their lowest single-sideband noise factors of around 4 dB and the intermediate-frequency (IF) bandwidths up to 20 GHz. Those achievement are attributed to innovative on-chip antenna and circuit designs as well as advanced device modelling and optimization methods. Those sensitive receiver frontends have been integrated into the THz communication systems for high-speed data transmission demonstrations.