Toshiba Corporation has developed a gallium nitride (GaN) power field effect transistor (FET) for the Ku-band (12GHz to 18GHz) frequency range that achieves an output power of 65.4W at 14.5GHz. The main application of the transistor will be in base stations for satellite microwave communications, which carry high-capacity signals, including high-definition broadcasts. Toshiba plans to start sample shipment of the power FET by the end of 2007 and to go into mass production by the end of March 2008. Advances in Ku-band microwave amplifiers focus on replacing the electron tubes conventionally used at this bandwidth with semiconductors, particularly GaN devices, which offer advantageous high power characteristics at higher microwave frequencies.

The power FET has a high electron mobility transistor (HEMT) structure that Toshiba has optimized for the Ku-band. The company replaced source wire bonding with via hole technology to reduce parasitic inductance, and also improved overall design of the matching circuit for practical application at Ku-band frequencies.