Miniaturized and high-efficiency end-reflective coaxial cerenkov oscillator

Abstract High-power microwaves have extensive applications, but their practical implementation necessitates miniaturized and efficient devices. This paper introduces a novel miniaturized and highly efficient end-reflective coaxial Cerenkov device for high-power microwave generation. The design incorporates a coaxial collector structure that achieves total reflection of forward waves, significantly enhancing the end-feedback effect without increasing the structural length. Additionally, an integrated coaxial diffractive structure works synergistically with the strong end-feedback structure. This configuration not only enables highly efficient microwave output but also establishes a strong modulation field in the diode region, thereby facilitating effective electron beam modulation without extending the device length. Simulations demonstrate an output microwave power of 2.82 GW at 9.1 GHz, with a power conversion efficiency of 54%. Notably, the axial length of the beam-wave interaction region is only 2.6 λ , substantially shorter than that of conventional high-efficiency Cerenkov oscillators. The unique combination of the strong end-feedback coaxial structure and the coaxial diffractive output contributes to achieving both high efficiency and miniaturization in the generator.