An in-line coaxial-to-circular waveguide transition at X band

Abstract

A wideband transition from the coaxial TEM mode to the TM01 mode of the circular waveguide with in-line input-output architecture is proposed in this paper. The transition employs multi-stage stepped impedance transformer to achieve wideband responses. Both mode transition and impedance matching characteristics are discussed in the paper. A demonstrator is developed and validated experimentally. As compared with some recently published reports, a better performance is observed. Moreover, the developed transition could facilitate the mechanical fabrication more easily. It can be found wide applications such as the circular waveguide based slot array antenna, the nondestructive detection, cracks inside the conductive pipes, and so on.

Computational Design of an In-Line Coaxial-to-Circular Waveguide Adapter with More Than an Octave Bandwidth

“…For some applications, it is advantageous to use an in-line adapter instead of a rightangle one. In-line CCWAs have mostly been studied for TEM-TM 01 mode conversion [17,18]. A thorough literature survey reveals that only two previous works [19,20] have been published on in-line TEM-TE 11 mode converters with broadband performance.…”