Extremely high efficient UHF power MOSFET for handy transmitter

A UHF Power MOSFET suitable for use in handy transmitter is reported, which can deliver 5.0W of output power with 72% drain efficiency and 6.0dB gain at 860MHz for 7.5V low supply voltage. A new Power MOSFET is analyzed by two dimensional computer simulation to realize low voltage operation at ultra high frequency. This device has a Bi-Well Structure for low on resistance and small parastic capacitance. For high frequency performance, 1.3µm channel length and metal gate are empolyed. This device has also very wide band frequency characteristics and is able to withstand infinite VSWR. Thus, a UHF Power MOSFET is considered to be a significant candidate for handy telephone, mobile radio and other handy communication systems.