The waveguide and the coaxial-probe type wideband high power TM0n-mode couplers (n=1,2) were designed and qualified with respect to the coupling factor using the wheel-type mode launchers. The mode launchers and the mode couplers were simulated and experimentally tested, the former for the VSWR and the latter for the coupling factor. The coupler chamber has been used in single-shot experiments, the values of the measured frequencies of coupled output of a typical vircator agreed with those predicted values by particle-in-cell code simulation using MAFIA.
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