Higher-order mode filtering by a resistive layer

TL;DR

This paper proposes a method to filter higher-order modes in air-filled waveguides using a resistive layer, optimizing modal attenuation while preserving the fundamental mode, validated through numerical simulations.

Contribution

It introduces a novel resistive layer technique for higher-order mode filtering in waveguides, based on an adapted Cremer's criterion.

Findings

Effective higher-order mode suppression demonstrated in simulations

Optimal resistive layer parameters identified

Method preserves fundamental mode integrity

Abstract

A method of higher-order modes filtering in an air-filled waveguide using a resistive layer is proposed. An analogue of Cremer's criterion is discussed and used to obtain the optimal modal attenuation of the non-planar waves while the plane wave is preserved. Numerical validation of the concept is performed for a straight waveguide and an abrupt expansion in a waveguide.