1.1 W/mm high power GaAs/InGaP composite channel FET with asymmetrical LDD structure at 26 V operation

A GaAs/InGaP composite channel is proposed in order to improve the electron transport properties of an InGaP FET. Adopting an LDD (Lightly Doped Drain) structure and optimizing gate to drain spacing improved the breakdown characteristic and enabled high voltage operation of the FET. With this novel FET, we could achieve a high output power density of 1.1 W/mm at high voltage operation such as 26 V. The FET showed better distortion characteristics than the conventional GaAs MESFET. Third order inter modulation distortion (IM3) was improved by 7 dB.