Title :
Cryogenic, HEMT, low-noise receivers for 1.3 to 43 GHz range
Author :
Weinreb, S. ; Pospieszalski, M.W. ; Norrod, R.
Author_Institution :
Nat. Radio Astron. Obs., Charlottesville, VA, USA
Abstract :
After a review of recent progress in cryogenically cooled high-electron-mobility-transistor (HEMT) devices and amplifiers, a description is given of the construction and performance of a number of receiver front-ends built for radioastronomy applications using very-low-noise HEMT amplifiers and small, closed-cycle 13 K refrigerators. The noise temperature of receivers, measured at the room temperature circular waveguide input (for example, 10.5 K at 8.4 GHz), are only slightly inferior to those of solid-state maser receivers. A summary of the noise performance of all cryogenic front-ends constructed or planned for the very long baseline array (VLBA), comprised of ten 25-m-diameter paraboloidal reflectors each located in a different site within the US, is given.<>
Keywords :
cryogenics; high electron mobility transistors; microwave amplifiers; radio receivers; radiotelescopes; solid-state microwave circuits; 1.3 to 43 GHz; 13 K; EHF; HEMT; MM-wave type; MODFET; SHF; VLBA; closed cycle refrigerator; cryogenically cooled; high-electron-mobility-transistor; low-noise receivers; microwave amplifiers; millimetre wave operation; noise performance; radioastronomy applications; receiver front-ends; very long baseline array; Background noise; Cryogenics; HEMTs; Low-noise amplifiers; Masers; Noise figure; Radio astronomy; Receivers; Superconducting device noise; Temperature;
Conference_Titel :
Microwave Symposium Digest, 1988., IEEE MTT-S International
Conference_Location :
New York, NY, USA
DOI :
10.1109/MWSYM.1988.22187
