Reduction of rectangular waveguide cross-section with metamaterials: A new approach

A new approach to design a metamaterial surface (meta-surface) with the objective of reducing the waveguide's cutoff frequency of the fundamental mode is proposed. From an analytical study of the dispersion diagrams of waveguides with anisotropic walls, a hypothesis for the surface impedances is set up. By means of this new hypothesis, the design of a unit-cell is optimized. Finally, the periodically arranged meta-surface is implemented in a miniaturized waveguide and the simulation results are compared to the ones of a metallic waveguide in order to validate the approach.