Superconductive hot electron mixers with ultra-wide RF bandwidth for heterodyne receiver applications up to 3 THz

摘要

The development of quasi-optical Nb hot-electron bolometer mixers for heterodyne receivers at 1.2 and 2.5 THz is reported. The devices have submicrometer in-plane sizes and exploit diffusion as the electron cooling mechanism. Quasi-optical mixer circuits were developed with planar double-dipole or twin-slot antennas. Specially designed THz test systems which avoid atmospheric absorption were used in the experiments. The measured receiver noise temperatures are 1900 K at 1.2 THz, with an estimated mixer noise temperature at 950 K, and 27580 K at 2.5 THz with an estimated mixer noise temperature of 900 K.