Numerical simulation of wave propagation in Y- and Z-type hexaferrites for high frequency applications

Abstract

In this work, we present a numerical approach for simulating wave propagation in unbounded domains which combines discontinuous Galerkin methods with arbitrary high order time integration (ADER-DG) and a stabilized modification of perfectly matched layers (PML). Here, the ADER-DG method is applied to Bérenger's formulation of PML. The instabilities caused by the original PML formulation are treated by a fractional step method that allows to monitor whether waves are damped in PML region. In grid cells where waves are amplified by the PML, the contribution of damping terms is neglected and auxiliary variables are reset. Results of 2D simulations in acoustic media with constant and discontinuous material parameters are presented to illustrate the performance of the method.

Consequences of magnetic anisotropy in realizing practical microwave hexaferrite devices

“…The use of these materials in microwave signal processing devices, such as phase shifters, delay lines, filters, etc. has also been demonstrated [6,9]. Here, we discuss the benefits of these materials in the development of low profile antenna elements, specifically as electronic bandgap metamaterial substrates.…”

“…Specialized numerical modeling tools need to be developed in such cases. One example is the application of the Galerkin's method in spectral domain to derive the dispersion relations and design a microwave phase shifter based on ZnY ferrite [6].…”

Synthesis, Structural, and Magnetic Properties of Ba3(ZnxMg1-x)2Fe24O41 Z-Type Hexaferrites

“…Z-type hexaferrites, on the other hand, had attracted attention due to their high initial permeability in frequency regions higher than 300 MHz, excellent electromagnetic properties, and ferromagnetic resonance frequency up to the GHz range. Therefore, these ferrites are considered to be promising materials for multilayer chip inductors (MLCI), phase shifters, and microwave absorbers in high frequency range [10][11][12][13][14][15][16]. Synthesis of pure Z-type hexaferrite is a real challenge due to the complexity of its structure, and the progressive transformation through intermediate phases before achieving the final required product [17][18][19].…”

Low-Loss Co<sub>2</sub>-Y Ferrites with Added CuO Sintered in Air for High Frequency Application

“…Ferrites and other magnetic materials have been widely used as the key elements in microwave devices [1]- [3] such as isolators, phase shifters [4] [5], and circulators [6]. Traditional ferrites, known as spinel types, such as Ni-Zn ferrites have been known to exhibit high permeability in the frequency range up to a few hundred MHz because of restriction by Snoek's law [7] [8].…”