Design of a high power solid state amplifier to replace TWTAs in airborne applications
Dominic FitzPatrick · 2000
This paper describes the amplifier design requirements for an airborne electronic counter measures (ECM) application, and the solid state solution successfully provided by Milmega. As a result of its earlier interest in microwave tube amplifiers Milmega received a requirement specification for a travelling wave tube amplifier, (TWTA), for an airborne ECM application. The basic requirements of the amplifier are summarized. An initial investigation by the design team suggested that a gallium arsenide field effect transistor (GaAs FET) solution would be a practical alternative to the TWTA approach. This approach afforded reliability levels that superseded the customer expectations. Milmega's proposed solid state solution was based on one of the company's standard products, a 3U 19" rack mounted 250 W 1 to 2 GHz solid state power amplifier (SSPA). The family of amplifiers on which the proposal was based was the outcome of a UK Government funded program which started in 1992 and enabled Milmega to develop rugged octave band amplifiers, initially intended for electronic warfare and EMC testing applications. The program objectives were to develop a range of 1-2 GHz and 2-4 GHz amplifier and power combiner modules which could be configured into amplifier systems delivering up to 200 W or 400 W CW at lower cost and with higher reliability than a TWTA. (8 pages)