This paper outlines the design characterization and the electromagnetic performance of a millimeter-wave high power combining structure, which exploits the spatial power combination technique. The input matching is always below 10 dB over the entire Q band, and the overall weight of the structure is about 500 g. Multiphysics simulations show how this structure is suitable for the most challenging space missions that will arise in next few years. In fact, 100 W of RF power above the frequency of 40 GHz can be delivered while all the specifications for satellite payloads are complied. Other Spatial Power Combiner structures, such as Radial ones, cannot be implemented in space missions since they are much less compact and much heavier than the one presented in this article, and this is the major advantage of this configuration which was specially designed for a space project.
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