A megawatt class compact power combiner for solid-state amplifiers

We propose a compact multiport two-stage combiner capable of handling peak power up to 10 MW at the UHF band and suitable for particle accelerator applications. The detailed electromagnetic and thermal simulations of the combiner operating at the ESS specifications of 400 kW at 352 MHz are presented. At the first stage, the power is combined to a 100 kW level by means of a non-resonant 12-way radial combiner, which is assumed to be fed by 8 kW solid-state amplifiers. At the second stage, a waveguide combiner with T-shape couplers separated by a half-wavelength of the fundamental waveguide mode is used in order to bring the combined power to the required level. The combiner is broadband and has a relative power non-uniformity less than 5% over a 10 MHz frequency band around the central frequency. The size of the proposed combiner is several times smaller than the existing ones. We also present low-power measurement results of a prototype of the radial combiner.