Magneto-Dielectrics in Electromagnetics: Concept and Applications

Abstract

Abstract-In this paper, the unique features of periodic magneto-dielectric meta-materials in electromagnetics are addressed. These materials, which are arranged in periodic configurations, are applied for the design of novel EM structures with applications in the VHF-UHF bands. The utility of theses materials are demonstrated by considering two challenging problems, namely, design of miniaturized electromagnetic band-gap (EBG) structures and antennas in the VHF-UHF bands. A woodpile EBG made up of magneto-dielectric material is proposed. It is shown that the magneto-dielectric woodpile not only exhibits band-gap rejection values much higher than the ordinary dielectric woodpile, but also for the same physical dimensions it shows a rejection band at a much lower frequency. The higher rejection is a result of higher effective impedance contrasts between consecutive layers of the magneto-dielectric woodpile structure. Composite magneto-dielectrics are also shown to provide certain advantages when used as substrates for planar antennas. These substrates are used to miniaturize antennas while maintaining a relatively high bandwidth and efficiency. An artificial anisotropic meta-substrate having , made up of layered magneto-dielectric and dielectric materials is designed to maximize the bandwidth of a miniaturized patch antenna. Analytical and numerical approaches, based on the anisotropic effective medium theory (AEMT) and the finite-difference time-domain (FDTD) technique, are applied to carry out the analyzes and fully characterize the performance of finite and infinite periodic magneto-dielectric meta-materials integrated into the EBG and antenna designs.Index Terms-Anisotropic effective medium theory (AEMT), antenna miniaturization, electromagnetic band-gap (EBG) materials, finite-difference time-domain (FDTD) technique, magneto-dielectrics, meta-materials, periodic structures.

Effects of Magneto-Dielectric Ceramics for Small Antenna Application

“…The loss tangent of permeability showed no significant differences with the composition. The real part of permittivity, loss tangent of the permittivity and real part of permeability, loss tangent of the permeability of the Ba 3 To investigate the feasibility of magneto-dielectric ceramics as materials for the antenna component, the antenna was simulated with CST (Computer Simulation Technology), which is used as a 3D electro-magnetic analysis tool. Fig.…”

“…Electrical wavelength, size and bandwidth of an antenna are related to relative permittivity (ε) and relative permeability (μ) [2]. The operating frequency and bandwidth of an antenna are determined as follows [3]. …”

Compact magneto-dielectric resonator MIMO antenna for angle diversity

“…In this manner, magneto-dielectric material offers a larger number of parameters of dielectrics to improve the performance and some characteristics of antennas as per the requirements for numerous applications [5]. By using such types of materials the matching and radiation efficiency is improved and it also provides low mutual coupling and a higher rejection level [6][7][8][9][10][11].…”

Tunable Periodic Microstrip Structure on Gaas Wafer

“…In the past, different mechanisms have been proposed, like electrooptic [2], magneto-dielectric [3], or use of gyrotropic slabs [4] for the purpose of changing the effective dielectric constant. Here a different, fully-electronic method is devised for these structures based on loading a microstrip.…”