Passive high-power microwave components

This review discusses the present state-of-the-art of passive high-power microwave components for applications in microwave systems for RF plasma generation and heating, plasma diagnostics, plasma and microwave materials processing, spectroscopy, communication, radar ranging and imaging, and for drivers of next generation high-field-gradient electron-positron linear colliders. The paper reports on high-power components for overmoded high-power transmission systems such as smooth-wall waveguides, HE₁₁ hybrid mode waveguides and quasi-optical TEM₀₀ beam waveguides. These include various types of mode converters, polarizers, cross-section tapers, bends, mode selective filters, pulse compressors, DC-breaks, directional couplers, beam combiners and dividers, vacuum windows, and instruments for mode analysis. Problems of ohmic attenuation and unwanted conversion to parasitic modes are discussed in detail and rules for alignment requirements are given. In the case of waveguide transmission, this review mainly concentrates on circular waveguide components but also deals with rectangular waveguide.