Matching of Radiation with Array of Planar Antennas with SINIS Bolometers in an Integrating Cavity

—Arrays of planar annular antennas in the 345 GHz range with integrated superconductor–insulator–normal metal–insulator–superconductor (SINIS) bolometers have been developed, fabricated, and experimentally investigated. To increase the absorption efficiency, the source signal was matched with the array using a back-to-back horn and a counter-reflector. The efficiency of the receiving structure was studied depending on the direction of irradiation—through the substrate and from the antenna—as well as on the thickness of the substrate. The methods for normalizing a received signal using a reference channel outside and inside a cryostat is described. The best results were obtained by irradiating the array from the antenna with a substrate thickness equivalent to a quarter wavelength in the dielectric and sputtering of the rear side with a gold film (counterreflector). The effective matching band in the main range was more than 50 GHz; the volt–watt sensitivity reaches 10 9 V/W.