Analytical calculation for input impedance of a circularly‐polarized ferrite disk antenna including higher order modes

Abstract

We propose an accurate analytical model for a circularly polarized antenna comprising a normally magnetized, grounded ferrite disk with a metalized top surface. The antenna is assumed to be excited by a conventional current probe. In the case of a thin ferrite disk, the electromagnetic fields of the dominant mode of the antenna do not vary in the direction normal to the disk. However, with increasing thickness of the ferrite disk, higher order modes start to affect antenna characteristics such as resonance frequency. This work presents an analysis of the structure that takes into account all higher modes of the antenna. To validate the theoretical calculations, HFSS simulations are performed. The antenna can be tuned by changing the magnetic bias field.

An Analytical Study of Magneto-Plasmons in Anisotropic Multi-layer Structures Containing Magnetically Biased Graphene Sheets

“…This hybrid waveguide is able to control the propagating properties of plasmonic waves both with chemical potential and magnetic bias. It should be mentioned that the usage of the ferrite materials at low THz frequencies has been reported in some research articles [56][57][58][59][60][61]. One of the drawbacks of utilizing the ferrite materials at the THz region is their necessity for high external magnetic fields to change the permeability at this region [56,62].…”