A novel patterned-SOI LDMOSFET with a silicon window beneath the p-type channel was designed and fabricated for RF power amplifier applications. This novel device has good DC and RF characteristics. It has no kink effect on output performance,an off-state breakdown of up to 13V,and fT = 6GHz at DC bias of Vg = Vd = 3.6V.At 1.5GHz,a power-added efficiency （PAE） of 50% is achieved with an output power of up to 27dBm from this device.
