Characteristics of broadband InP HFET millimeter-wave amplifiers and their applications in radioastronomy receivers

Developments in ultra-low-noise, heterostructure field-effect transistor (HFETs) receivers for frequencies up to 110 GHz are reviewed. Design and examples of the realization of InP HFET receivers in the frequency range 26 to 110 GHz are described. Applications to ultra-low-noise radio astronomy receivers, as well as broadband continuum radiometers, are discussed.