Low-Noise Amplifier at 2.45 GHz [TC Contests]

An LNA with 15 K noise at 2.45 GHz working at ambient temperature has been developed using the GaAs metamorphic HEMT iT8002D manufactured by GigOptix. Unfortunately, this transistor has been discontinued. We replaced iT8002D by the FHX45X, general purpose GaAs SuperHEMT manufactured by Eudyna in the same circuit. FHX45X has the same gate width of 280 um. The measured S parameters were quite similar to the original LNA. The noise was increased to about 18 K at 2.45 GHz. We feel that FHX45X can be used as a replacement for the iT8002D. Based on the results of this LNA, we are developing a wideband (0.54 GHz) LNA that will work at ambient temperatures as well as cryogenic temperatures for radio astronomy applications.