scholarly journals Effective permittivity of 3D lossy dielectric composite materials

1999 ◽  
Vol 35 (3) ◽  
pp. 1223-1226 ◽  
Author(s):  
P. Clauzon ◽  
L. Krahenbuhl ◽  
A. Nicolas
Keyword(s):  
Composite Materials ◽  
Effective Permittivity ◽  
Dielectric Composite ◽  
Lossy Dielectric

Microwave Dielectric Properties of Lossy Dielectric Composite Materials

2006 ◽  
Vol 45 (9B) ◽  
pp. 7489-7493 ◽  
Author(s):  
Young Joon An ◽  
Hirotake Okino ◽  
Takashi Yamamoto ◽  
Shunkichi Ueda ◽  
Takeshi Deguchi
Keyword(s):  
Composite Materials ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Dielectric Composite ◽  
Lossy Dielectric

Permittivity of Dielectric Composite Materials Comprising Graphene Nanoribbons. The Effect of Nanostructure

2013 ◽  
Vol 5 (15) ◽  
pp. 7567-7573 ◽  
Author(s):  
Ayrat Dimiev ◽  
Dante Zakhidov ◽  
Bostjan Genorio ◽  
Korede Oladimeji ◽  
Benjamin Crowgey ◽  
...  
Keyword(s):  
Composite Materials ◽  
Graphene Nanoribbons ◽  
Dielectric Composite

scholarly journals 3D-Simulation of Topology-Induced Changes of Effective Permeability and Permittivity in Composite Materials

2007 ◽  
Vol 2007 ◽  
pp. 1-8 ◽  
Author(s):  
B. Hallouet ◽  
R. Pelster
Keyword(s):  
Composite Materials ◽  
Effective Permeability ◽  
Filling Factor ◽  
Effective Permittivity ◽  
Matrix Material ◽  
Systematic Difference ◽  
Material Parameters ◽  
Effective Medium Model ◽  
Permittivity And Permeability ◽  
Induced Changes

We have performed 3D simulations of complex effective permittivity and permeability for random binary mixtures of cubic particles below the percolation threshold. We compare two topological classes that correspond to different spatial particle arrangements: cermet topology and aggregate topology. At a low filling factor off=10%, where most particles are surrounded by matrix material, the respective effective material parameters are indistinguishable. At higher concentrations, a systematic difference emerges: cermet topology is characterized by lower effective permittivity and permeability values. A distinction between topological classes might thus be a useful concept for the analysis of real systems, especially in cases where no exact effective-medium model is available.

scholarly journals On the Bergman–Milton bounds for the homogenization of dielectric composite materials

2007 ◽  
Vol 271 (2) ◽  
pp. 470-474 ◽  
Author(s):  
Andrew J. Duncan ◽  
Tom G. Mackay ◽  
Akhlesh Lakhtakia
Keyword(s):  
Composite Materials ◽  
Dielectric Composite

scholarly journals Accurate Measurement of the True Plane-Wave Shielding Effectiveness of Thick Polymer Composite Materials via Rectangular Waveguides

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1603 ◽  
Author(s):  
Moučka ◽  
Goňa ◽  
Sedlačík
Keyword(s):  
Composite Materials ◽  
Plane Wave ◽  
Effective Permittivity ◽  
Maximum Amplitude ◽  
Polymer Materials ◽  
Shielding Effectiveness ◽  
Amplitude Error ◽  
Isotropic Composite ◽  
S Parameters ◽  
Rectangular Waveguides

This paper presents a methodology for accurately gauging the true plane wave shielding effectiveness of composite polymer materials via rectangular waveguides. Since the wave propagation of the waveguides is not in the form of plane wave patterns, it is necessary to post-process the S-parameters for the measured data of the waveguide lines to obtain such patterns and ascertain the effectiveness of true plane wave shielding. The authors propose two different methods to achieve this. The first applies simple renormalization of S-parameters, where reference impedance is changed from the value for the waveguide to that for free space, which ensures good accuracy of shielding effectiveness with a small degree of discontinuity across the range of frequencies. The other relies on rigorous extraction of the composite materials’ effective permittivity and permeability ascertained from rectangular waveguides; afterward, plane wave shielding effectiveness is calculated analytically and gives very high accuracy. Both procedures assume the given samples are isotropic in character. We validated the accuracy of the methodologies by conducting tests on a set of synthetic samples of 2 mm thickness with unit permittivity and variable conductivity and on a dielectric material of known permittivity (FR4 laminate). The applicability of both methods was further proven by analyzing the isotropic composite materials, a process involving the use of iron particles embedded in a dielectric matrix. The synthetic samples and an FR4 material were tested to check the accuracy of the methods. Based on numerical studies and measurements, we concluded that materials with a shielding effectiveness of up to 25 dB could be measured at a maximum amplitude error of 1 dB to 3dB to a frequency of 18 GHz, depending on the relative permittivity of the material; hence, the first method was suitable for approximation purposes. For maximal accuracy, the second method typically demonstrated an amplitude error of below 0.5 dB to the same frequency across the entire range.

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