Title :
A Cooled Schottky-Diode Mixer for 75-120 GHz
Author :
Räisänen, Antti V. ; Predmore, C.Read ; Parrish, Peter T. ; Goldsmith, Paul F. ; Marrero, Jose L.R. ; Kot, Richard A. ; Schneider, Martin V.
Author_Institution :
Five College Radio Astronomy Observatory, 619 I Graduate Research Center, University of Masschusetts, Amherst, MA 01003, USA; Helsinki University of Technology, Radio Laboratory, Otakaari 5 A, SF-02150 ESP00 15, Finland.
Abstract :
A cryogenic, ultra low noise mixer has been designed and built at the Five College Radio Astronomy Observatory. New details of this mixer include improved waveguide, backshort, RF-filter and IF-matching and bias circuit designs. The mixer works evenly at frequencies 75-120 GHz. This mixer is used in a cooled receiver (15 K) where LO is coupled by an adjustable ring-filter and the mixer is followed by a 4.5-5.0 GHz IF system of TIF = 24 K. For the receiver we measured Trec, DSB = 140 K at fLO = 110 GHz when the LO power was only 30 ¿W. This result implies a mixer noise temperature of TM, DSB < 60 K.
Keywords :
Circuit noise; Circuit synthesis; Coupling circuits; Cryogenics; Educational institutions; Frequency; Observatories; Power measurement; Radio astronomy; Receivers;
Conference_Titel :
Microwave Conference, 1980. 10th European
Conference_Location :
Warszawa, Poland
DOI :
10.1109/EUMA.1980.332788
