SBIR-STTR Award

During the past 10 years significant progress has been made in the performance characteristics of solid-state devices. The output power capability has substantially increased, the efficiency has almost doubled, the reliability, when operated conservatively, has always been better than tubes because of graceful degradation characteristic, and the cost per device has decreased. These and other positive solid-state amplifier characteristics will be applied to the design of a state-of-the-art 5 Kw, 1500 Mhz, 40% efficient, 45 dB amplifier that could replace the present Continuous Electron Beam Accelerator Facility (CEBAF) klystron tube. The use of an integral dc to dc converter will be investigated. The converter would be part of the amplifier package and would enable the amplifier to run directly from the 11.6 kV dc voltage bus that presently exists. The end result would be an amplifier with better efficiency, more gain, better reliability, easier maintenance and lower system operating cost than the existing tube. In addition, the amplifier could replace the existing tube with only minor system modifications. Anticipated Results /Potential Commercial Applications as described by the awardee:The successful development of this amplifier should be directly beneficial to CEBAF where it can potentially replace 338 klystrons. There could also be a large potential commercial application in the new personal communication services band from 1.85 to 2.2 GHz.

During the past ten years significant progress has been made in the radio frequency (rf) power handling capabilities of solid state devices. These developments have led to suggestions that solid state rf power amplifiers might even invade the domain of "ridded tubes and klystron applications. In Phase I, a solid state amplifier for fixed frequency operation at a nominal center frequency of 1500 MHz was designed with an output power of five kW, a minimum gain of 35 dB, and an efficiency greater than 40%. The amplifier developed during Phase I had a minimum overall efficiency of 45% and a gain of 38 dB. In Phase II, the design will be completed and a prototype will be fabricated. The prototype will be tested at the Continuous Electron Beam Accelerator Facility (CEBAF) in an actual klystron socket to demonstrate performance. A parallel effort will be undertaken to design an amplifier which will address cost minimization and commercialization of the product. The first goal of the Phase II project, in addition to advancing the state-of-the-art for L-band solid state amplifiers, is to develop a prototype that is interchangeable with the klystrons used at present in the CEBAF accelerator.Anticipated Results/Potential Commercial Applications as described by the awardee: The successful development of this solid state rf power amplifier should allow commercialization in frequencies from ultrahigh to S-band. Replacing klystrons and gridded tubes with solid state devices promises better reliability and longer component life which are important factors in the communication industry.