A two-stage 8-12 GHz (X-band) cryogenically-cooled Low-Noise Amplifier (LNA) has been developed with a commercial pseudomorphic HEMT on GaAs substrate. In a first step, different commercial transistors have been fully characterized from 300 K to 20 K using a new method to measure the four noise parameters. Preliminary results have allowed the selection of the best device. This enabled the design of the two-stage LNA with the help of a microwave CAD software. In a second step, the LNA has been characterized at 300 K, 30 K and 4 K. As the physical temperature decreased from 300 K to 30 K, the LNA exhibited an average gain increase of 2 dB and as much as a fourfold reduction of noise temperature. A noise figure of 22.5 K and a gain of 23 dB have been achieved at 30 K around 10 GHz. The noise temperature has been furthermore reduced to 20 K by cooling the amplifier at the liquid helium temperature (4.2 K). Different methods to measure the noise characteristics of the amplifier are widely developed in this paper.
A low-noise cryogenically-cooled 8-12 GHz HEMT amplifier for future space applications
Ein rauscharmer, kryogenisch gekühlter HEMT-Verstärker für 8-12 GHz für den zukünftigen Einsatz im Weltraum
International Journal of Infrared and Millimeter Waves ; 18 , 1 ; 85-99
1997
15 Seiten, 16 Bilder, 1 Tabelle, 19 Quellen
Aufsatz (Zeitschrift)
Englisch
rauscharmer Verstärker , X-Band , Tieftemperaturtechnik , HEMT (High Electron Mobility Transistor) , Galliumarsenid , Rauschmessung , Wärmerauschen , rechnerunterstützter Entwurf , Verstärkung , Rauschtemperatur , Kühlung , Raumfahrt , Radioastronomie , Substrat , Millimeterwelle , Submillimeterwelle , Helium
A Low-Noise Cryogenically-Cooled 8-12 GHz HEMT Amplifier for Future Space Applications
British Library Online Contents | 1997
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