MM wave quasioptical SIS mixers

SIS Junctions for Millimeter and Submillimeter Wave Mixers

We have developed a process for the fabrication of highquality Nb/AlOx/Nb tunnel junctions with small area and high current densities for the heterodyne mixers at millimeter and submillimeter wavelengths. Their dc I-V curves are numerically studied, including the broadening of quasiparticle density of states resulting from the existence of an imaginary part of the gap energy of Nb. We have foun...

MMA RECEIVERS: SIS mixers

Revision History: 1998-09-21: Added chapter number to section numbers. Placed specifications in table format. Added milestone summary. 1999-04-09: Revised date format to conform to MMA standard. Updated milestone table. Added description of new SIS junction fabricator. 1999-04-15: Updated milestone table. Added Figs. 5.3.4(c) and 5.3.4(d). Added subsections 5.3.2.3.1 and 5.3.2.3.2. Revised sect...

Coherent Detection and Sis Mixers

Submillimeter spectroscopy is a unique and very rich source of astrophysical information. While many important results have been obtained using ground based telescopes, the Kuiper Airborne Observatory, ISO, and SWAS, this field will soon experience rapid growth and development due to projects such as SOFIA, ALMA, and the Herschel Space Observatory (HSO). High spectral resolution is and will con...

Simulated performance of multi-junction parallel array SIS mixers for ultra broadband submillimeter-wave applications

Quasi-optical submillimeter-wave SIS mixers with NbN/A1N/NbN tunnel junctions

We report on low-noise heterodyne mixing with NbN/A1N/NbN tunnel junctions in the submillimeter-wave region for the first time. The receiver consists of the quasi-optical NbN SIS mixer with an integrated tuning circuit in which a radial short stub tuner is incorporated to resonate out the junction capacitance for RF matching and a balanced IF circuit for broadband IF matching. The prepared NbN ...