Equivalent Surface Impedances for Below-Cutoff Propagation in Circular Waveguides

摘要

A relation between a metamaterial (MTM) liner for a circular waveguide and its equivalent surface impedance is made to allow for the replacement of the MTM liner with a metasurface (MTS). The equivalent surface impedance is found over a frequency range in a representative MTM-lined waveguide design. A below-cutoff backward-wave propagation region is successfully predicted by the MTS theoretical model.