Design and Fabrication of S-band Ultra High Power Transistorized Amplifier

마이크로파대 고출력 트란지스터 증폭기의 설계와 시작

Conventionally, a TIVT has been used for high power amplification in the microwave frequency range. However, an ultra-high-power amplifier in the 2GHz range has successfully been designed and fabricated employing high power transistors developed recently and available commercially. In the design of the amplifier, a balanced-pair configuration is adopted in order to obtain very high microwave power, and a good impedance matching is achieved by making use of microstripline techniques. For the RF power divider as well as combiner, an approach of stripline directional coupler isadopted because of its easiness in fabrication. The coupler so designed and fabricated indicates a satisfactory performance as a quadrature hybrie coupler. Measurements on the amplifier developed for an immediate commercial application also exhibit excellent overall performance characteristics RF power output, 14 watts, gain 14dB, frequency bandwidth, 160MHz, effciency 40%.

주로 TWT로 사용되어 오던 2GHz 대 고출력증식기를 근래 개발되어 시판되기 시작한 microwave bipolar transistor를 사용하여 설계 제작하였다. 특히 고출력을 얻을 목적으로 balanced amplifier로 구성하였으며 microstripline을 사용해서 우수한 impedance정합효과를 얻었다. RF출력의 divider 및 combiner로서는 제작상의 편의를 감안해서 stripline directional coupler방식을 채택했으며 이것은 quadrature hybrid coupler로서 좋은 동작특성을 보였다. 직접 실용화를 감안해서 설계, 시작된 본 마이크로파 트랜지스터 증폭기는 측정결과 RF출력 14watt, 이득 14dB, 편파수대역폭 180MHz, 효율 40%의 우수한 종합특성을 얻었다.