Research On Characteristics And Non-linear Fitting Of The Electromagnetic Metamaterials Parameters

Electromagnetic metamaterial is a kind of artificial structural material which has aspecial performance, its permittivity or permeability will exhibit negative under certainconditions. This unconventional electromagnetic characteristics will generate manyunusual phenomenon, and received considerable attention. Many research teamsconducted a great deal of work, and achieved fruitful results. Electromagneticmetamaterials have broad application prospect, it will have a profound impact onhumans.This paper focuses on the characteristics of electromagnetic metamaterialparameters, and derives the expressions of electromagnetic metamaterial parameters,verifies the correctness of the expressions by nonlinear fitting. In the process ofderivation, we base on the passive Maxwell’s equations, let the electromagneticmetamaterial plate equivalent to surface current and surface magnetic current, useperiodic boundary conditions and the superposition principle, we can calculate the totalelectric fields expressions and the total magnetic fields expressions. In the Electricresonance and the magnetic resonance metamaterial, we introduce magnetic or electricanti-resonance, by the total electric field expression and the total magnetic fieldexpression, the Bloch impedance and the spatially dispersion relation of the periodicstructure can be deduced, thus we can get the Bloch constitutive parametersexpressions of the electrical resonance and the magnetic resonance metamaterials. Bythe total electric field expression and the magnetic field expression, we can establish aEquation associated with surface current density amplitude and the surface magneticcurrent amplitude, then the dispersion relation of electromagnetic metamaterials can beobtained. According to the dispersion relation, we can get the refractive indexexpression of electromagnetic metamaterial.The nonlinear fitting part of this paper is mainly accomplished by HFSSsimulation software and Matlab software. Using the HFSS software, we construct themetamaterial units and simulate the metamaterial units, then we can get the scatteringparameters of the metamaterial unit. Next, we import the scattering parameters intoMatlab software, through the S-parameter retrieval method and the nonlinear fittingtechnique, we can plot the parameters extraction and the parameters theoretical curve. At last, we find the error between the theoretical curve and the extract curve is verysmall, it shows the parameters expressions of the electromagnetic metamaterial iscorrect.