High-Power RF Window

72383-Conventional waveguide windows for extremely high-power microwave systems are close to their power-handling-capability limits. Further efforts along conventional lines invite problems with higher-order modes, thermal cooling, and thermo-mechanical stresses. The basic problem with the conventional approach is that the microwave power is forced through a single disk window. This project will develop a distributed microwave window concept in which the power is transmitted through a series of ceramic-filled apertures. In Phase I, mode-matching field theory and software were developed for both scattering parameter and trapped-mode characterization in the new window geometry. Mockup prototype windows were designed, fabricated, and tested at low-power, successfully demonstrating the suitability of the approach to high-power window design. Measured scattering parameters and mode resonance frequencies correlated well with calculated values, which demonstrated the technical feasibility of this microwave window. Phase II will develop additional theory and software for advanced compact configurations of the distributed window. Additional cold-test prototypes (non-brazed) will be designed, built, and tested at low-power. Commercial Applications and Other Benefits as described by awardee: The high-power microwave windows should find use in radar, fusion, and particle accelerator applications. Also, the dual injection feature of the distributed window lends would be useful for studying the nonlinear properties of the dielectric material used in the window¿s ceramic-filled coupling apertures.