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Article
Publication date: 27 September 2011

Oleg Rybin, Konstantin Yemelyanov, Amjad Pitafi and Tahira Nawaz

The purpose of this paper is to study the microwave behaviour of effective magnetic permeability for two‐component ferrite like metamaterial medium in the direction of a…

Abstract

Purpose

The purpose of this paper is to study the microwave behaviour of effective magnetic permeability for two‐component ferrite like metamaterial medium in the direction of a biasing magnetic field. The metamaterial medium is presented as an infinite host dielectric material (air) with periodically embedded ferric cylindrical and spherical inclusions saturated with an external dc magnetic field. The study is based on the effective medium theory developed for polycrystalline metaferrites. The simulations show that the presented metamaterial can exhibit the ultra‐low refractive index (ULI) phenomenon and the phenomenon of negative magnetic permeability for the case of microwave propagation in the direction of bias.

Design/methodology/approach

The obtained results are based on the wave long approximation of permeability tensor of the presented metamaterial media obtained earlier by the first author. Using the standard approach, the authors apply the above expressions for the microwave propagation in direction of biasing dc magnetic field considering different polarization of the incident microwave.

Findings

The considered artificial material media can become either material with a ULI or with negative values in the GHz frequencies.

Originality/value

The paper is concerned with part of the theory of a new generation of artificial ferrites.

Details

Multidiscipline Modeling in Materials and Structures, vol. 7 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 9 August 2011

Oleg Rybin, Konstantin Yemelyanov and Tahira Nawaz

The purpose of this paper is to obtain the long‐wave approximations for the effective electromagnetic response of two‐dimensional sandwich composite structure, as infinite…

Abstract

Purpose

The purpose of this paper is to obtain the long‐wave approximations for the effective electromagnetic response of two‐dimensional sandwich composite structure, as infinite chain of infinitely long metal cylinders symmetrically immersed in an infinite metamaterial slab are obtained. The slab is an infinite magneto‐dielectric matrix with periodically imbedded infinitely long metal cylinders whose diameter is smaller than those of the chain cylinders. The case of ferrite‐like metallic saturated inclusions is considered in the study.

Design/methodology/approach

The result is presented as a generalized expression of the electromagnetic response of the infinite periodic chain of infinitely long metallic cylinders immersed into the flat magneto‐dielectric host medium. Those expressions were obtained utilizing S‐ and T‐matrices approaches.

Findings

A good coincidence between the results of analytical modeling and numerical simulations was found.

Research limitations/implications

Low values of the metal volume fraction; microwave frequency range.

Practical implications

An improving of directivity of patch antennas; a minimization of patch antennas.

Originality/value

The analytical characterization of new artificial substrate‐like structure to be utilized for designing patch antennas of a new generation.

Details

Multidiscipline Modeling in Materials and Structures, vol. 7 no. 2
Type: Research Article
ISSN: 1573-6105

Keywords

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