Low Noise Amplifiers Using Two Dimensional Electron Gas FETs

Recently developed LNAs incorporating two dimensional electron gas (2 DEG) FETs for satellite communications earth stations are disclosed, which give epoch-making low noise as FET LNAs to operate. in the 2, 4, 12, and 20 GHz bands at room temperature, especially under cooled state. Typically detailed further is newly developed 4 GHz band LNA with 55 K max. noise temperature at room temperature, noise temperatures of the order of 30 K across 800 MHz bandwidth (3.4 to 4.2 GHz) under thermoelectrically (TE- ) cooled state (about-45°C), which has been adopted in the new earth station conducted by KDD.