Fundamental mode selection thanks to metamaterial wall insertion in waveguides

Abstract

In this paper, a new application of metamaterials is put forward, the selection of the fundamental mode of waveguides. To demonstrate this new application, the Modal Expansion Theory (MET) hybridized with a 2‐D Finite Element Method (FEM) is used. The procedure to design metamaterial waveguides using the MET is also introduced. This method is used to design a corrugated waveguide with a TM01 mode as fundamental mode, knowing that in metallic waveguide the fundamental mode is the TE11. As a proof of concept, this metamaterial waveguide is fabricated as well as the metallic waveguide. Both waveguides are excited with the TE11 mode, which results in a standard propagation of this mode in the metallic waveguide, and no propagation in the corrugated waveguide. To excite the TM01, a new Coaxial to Waveguide Transition is developed and presented in the paper. Both, simulations and experiments are carried out in order to verify and prove the fact that the fundamental mode of the corrugated waveguide is the TM01 mode.