Millimeter Wave Power Generation with Quasi-Optical Power Combining Arrays

A promising new approach for high power solid-state sources will be demonstrated using spatial power combining grids. Present development of high power field effect transistor (FET) based solid-state sources at millimeter-wave frequencies is hampered by the limited power output of individual sources and the costs and power losses associated with combining a large number of sources using conventional approaches. However, the solid-state source offers the advantages of improved performance compared to vacuum tube power sources. Improved efficiency and reliability of millimeter-wave power sources is crucial to future generations of radar, communications, and sensing systems especially those operating in a space based environment. The proposed approach will use power combining arrays of FET based power generators. This method allows low loss combining ofa large number of FET sources at low cost by using monolithic integration. Critical elements addressed in the proposed program are impedence matching of devices for maximum power output and thermal analysis of heat sinking provided by various packaging approaches. Frequencies of 35, 60, and 94 GHz will be considered. At completion of Phase I, an initial array design and package design capable of generating 5-10 Watts at millimeter-wave frequencies will be developed. Anticipated Benefits: Benefits include low cost, high reliability, highly efficient millimeter-wave power sources for use in various wireless communications, radar, and meteorological sensing. Potential commerical applicatoins include high data rate communications and vision systems for "seeing" through smoke and fog.