# Control of single-mode operation in a circular waveguide filled by a longitudinally magnetized gyroelectromagnetic medium

## TL;DR

This paper explores how a longitudinally magnetized ferrite-semiconductor composite filling in a circular waveguide can be used to control the dispersion and mode operation, enabling single-mode and isolated mode propagation.

## Contribution

It introduces a method to control dispersion features of waveguide modes using a composite gyroelectromagnetic filling, identifying frequency bands for single-mode operation.

## Key findings

- Identified three frequency bands with single-mode operation.
- Demonstrated the possibility of isolated HE11 mode propagation.
- Analyzed the relation between resonant conditions and dispersion features.

## Abstract

A substantial control of dispersion features of the hybrid EH01 and HE11 modes of a circular waveguide which is completely filled by a longitudinally magnetized composite finely-stratified ferrite-semiconductor structure is discussed. A relation between the resonant conditions of such a composite gyroelectromagnetic filling of the circular waveguide and dispersion features of the supported modes are studied. Three distinct frequency bands with the single-mode operation under normal as well as anomalous dispersion conditions of the EH01 mode are identified by solving an optimization problem with respect to the filling factors of the composite medium. The possibility of achieving isolated propagation of the HE11 mode is revealed.