Development of a Solid State Radio Transmitter with MOS/FET

This paper presents a new type of radio transmitter using power MOS-FETs. This new version employs power MOS-FETs in its RF power amplifier and modulator. An RF power amplifier of push-pull or dual SEPP configuration with a power gain of 20dB easily generates high power in the order of kilo-watts. The new RF power amplifier, having output power of 0.3, 0.4, 0.6, 1.0, 2.0, or 3.0kW, features a drain efficiency of 90% because of favorable MOS-FET characteristics as wide-ASO, negative aID/aT* coefficient, no current hogging, and no carrier storage. The modulator consisting of power MOS-FETs has an efficiency of approximately 90% at 100kHz. (*Variation of the drain current with temperature)