# Design Procedure for a Broadband TE11/HE11 Mode Converter for High-Power Radar Applications

Haas, Daniel; Thumm, Manfred

##### Abstract:
The HE$_{11}$ hybrid mode, propagating in an overmoded corrugated circular waveguide, is widely used for low loss transmission of high-power microwaves. Due to the inherent broadband frequency behaviour, this will be also essential for future broadband high-power radar applications, like space debris observation in low earth orbit (LEO). A promising amplifier concept for such radar sensors is a helical gyro-TWT. However, since the HE$_{11}$ hybrid mode is not suitable for electron-beam-wave interaction in this kind of vacuum electron device, an additional mode converter is required. The present paper addresses the design procedure of a broadband high-power mode converter, designed for a helical gyro-TWT intended for future broadband high-power radar applications in the W-band. The interaction mode of the helical gyro-TWT under consideration can be easily transferred to the circular waveguide TE$_{11}$ mode. Therefore, a TE$_{11}$ ↦ HE$_{11}$ mode converter is addressed here. The design procedure is based on a scattering matrix formalism and leads to a high HE$_{11}$ mode content of ≥98.6% within the considered frequency range from 92 GHz to 100 GHz. ... mehr

 Zugehörige Institution(en) am KIT Institut für Hochleistungsimpuls- und Mikrowellentechnik (IHM) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2021 Sprache Englisch Identifikator ISSN: 1866-6892, 0195-9271, 1572-9559, 1866-6906 KITopen-ID: 1000130921 HGF-Programm 31.13.02 (POF IV, LK 01) Plasma Heating & Current Drive Systems Erschienen in Journal of Infrared, Millimeter, and Terahertz Waves Verlag Springer Verlag Nachgewiesen in Scopus
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