A new GaAs power-MESFET with large unit gate width

A novel GaAs power-FET is proposed which uses an additional transmission-line feeder parallel to the gate. With a suitable termination at the end of this transmission line and a unit gate width of 2 mm, the fabricated device shows excellent power-handling capabilities and an increased output resistance at 4 GHz. It is demonstrated that this approach leads to higher output power and easier matching of GaAs power FETs. Measurements show that the additional transmission line reduces the losses of the gate electrode to 3 dB/mm at 8 GHz. The input resistance of an FET with a 2-mm-wide gate is about 40% higher than that of an FET with two gates of 1-mm width in parallel. In addition, because of the large number of via holes an excellent thermal resistance of 20 K/W (1-mm gate width) is obtained.<>