title: Cryogenic microwave amplifiers for precision measurements.
abstract: The noise performance of two cryogenic HEMT amplifiers has been studied. The effective noise temperature for each amplifier is shown to be close to the 6 K thermodynamic temperature before a power threshold of about -70 dBm is achieved.
authors.affiliation: Dept. of Phys., Western Australia Univ., Nedlands, WA, Australia.
authors.forename: E N
authors.initials: EN
authors.lastname: Ivanov
authors.forename: J G
authors.initials: JG
authors.lastname: Hartnett
authors.forename: M E
authors.initials: ME
authors.lastname: Tobar