High-power operation of III-N MOSHFET RF switches

We describe a large-signal performance of novel highpower radio frequency (RF) switches based on III-nitride insulated gate metal-oxide semiconductor heterostructure field-effect transistors (MOSHFETs). The maximum switching powers for a single MOSHFET with only 1-mm gate width exceed 50 W at 10 GHz, more than an order of magnitude higher than those achievable using GaAs transistors. In the ON state, the highest powers are determined by the device peak drain currents, 1-2 A/mm for the state-of-the art III-N MOSHFETs; in the OFF state their maximum powers are limited by the breakdown voltage, normally well above 100 V. Our experimental data are in close agreement with large-signal simulations and the proposed simple analytical model. We also show that the insulating gate design allows for broader hand-width and higher switching powers and better stability as compared to conventional Schottky gate transistors.