Extraction of Permittivity and Permeability for Ferrites and Flexible Magnetodielectric Materials using a Genetic Algorithm


A hybrid approach, based on the two-dimensional finite-element method (2-D-FEM) and a genetic algorithm (GA) optimization, is used to extract relative permittivity and permeability of ferrites and flexible magnetodielectric composite materials over wide frequency bands. S-parameters of a material under test (MUT) placed into a coaxial fixture are measured by a vector network analyzer and simulated using the 2-D-FEM code. The GA optimization procedure is then used to minimize the discrepancies between the measured and simulated S-parameters by iteratively searching the possible best permittivity and permeability. Multiterm Debye models of wideband complex permittivity and permeability are employed here for a frequency-dispersive MUT. This greatly reduces the number of unknowns in the GA optimization. The proposed method is tested with PTFE and a virtual magnetic material.


Electrical and Computer Engineering

Research Center/Lab(s)

Center for High Performance Computing Research

Second Research Center/Lab

Electromagnetic Compatibility (EMC) Laboratory

Keywords and Phrases

Algorithms; Complex networks; Electric network analyzers; Ferrite; Ferrites; Frequency bands; Genetic algorithms; Gyrators; Hybrid materials; Iterative methods; Magnetic materials; Permittivity; Scattering parameters; Complex permittivity and permeabilities; Dispersive media; Genetic-algorithm optimizations; Magneto-dielectric composites; Magnetodielectric materials; Relative permittivity and permeability; Two dimensional finite element method; Vector network analyzers; Finite element method

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


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© 2015 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jun 2015