Quasi-optical SIS mixers with normal metal tuning structures

• Published in: IEEE transactions on applied superconductivity Vol. 7; no. 2; pp. 3584 - 3588
• Main Authors: Mei Bin, Gaidis, M.C., Zmuidzinas, J., Phillips, T.G., LeDuc, H.G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.1997; Institute of Electrical and Electronics Engineers
• Subjects: Antenna measurements; Applied sciences; Circuit noise; Circuit optimization; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Fourier transforms; Frequency measurement; Frequency response; Lenses; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Niobium; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; Superconducting devices; Temperature
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/77.622176

We recently reported (1996) a quasi-optical SIS mixer which used Nb/Al-oxide/Nb tunnel junctions and a normal-metal (Al) tuning circuit to achieve an uncorrected receiver noise temperature of 840 K (DSB) at 1042 GHz. Here we present results on several different device designs, which together cover the 300-1200 GHz frequency range. The mixers utilize an antireflection-coated silicon hyper-hemispherical lens, a twin-slot antenna, and a two-junction tuning circuit. The broad-band frequency response was measured using Fourier transform spectrometry (FTS), and is in good agreement with model calculations. Heterodyne tests were carried out from 400 GHz up to 1040 GHz, and these measurements agree well with the FTS results and with calculations based on Tucker's theory (1985).