DEVELOPMENT OF AN FDTD TOOL FOR MODELING OF DISPERSIVE MEDIA Part I. Material parameters and updating equations for fields
نویسندگان
چکیده
The implementation of the Debye, narrowband Lorentzian, and wideband Lorentzian dielectric and magnetic media in the numerical tool EZ-FDTD developed at the University of Missouri-Rolla (UMR is described. This tool allows efficient and robust full-wave finite-difference time-domain modeling of different complex electromagnetic structures. Algorithms for dispersive media use the linear recursive convolution (LRC) procedure. Fitting the experimentally obtained frequency characteristics of the materials by the Debye and Lorentzian dispersive laws is discussed. Criterion of which model is to be applied is introduced. The Debye model can be used, if the Q-factor of the linear circuit analogue of the corresponding Lorentzian model is less than 0.8. If 0.8 < Q < 1, then the wideband Lorentzian model is appropriate. For Q > 1, the narrowband Lorentzian model must be applied. The narrowband Lorentzian model is suitable for materials exhibiting resonance effects in the microwave frequency range. The wideband Lorentzian curve is typical for composites filled with conducting fibers, and also for many microwave magnetic materials.
منابع مشابه
Electromagnetic Field Due to Lightning Strikes to Mountainous Ground
The produced electric and magnetic fields due to lightning strikes to mountainous ground are determined in this paper. For the sake of simplicity a cone-shaped ground with finite conductivity is assumed to represent a natural nonflat ground. By this assumption, we deal with an axillary symmetrical structure so we use the cylindrical 2D-FDTD to save the simulation memory and time, dramatically. ...
متن کاملAn FDTD Formulation for Wave Propagation in Biological Dispersive Media
A Finite Difference Time Domain (FDTD) scheme used to model the wave propagation in biological dispersive media has been proposed in this paper. FDTD scheme based on the direct solution of time domain Maxwell’s equations has developed and these solutions were approximated by time based linear functions. We are applied FDTD scheme for different dispersive media models such as Cole-Cole, Cole-Dav...
متن کاملFinite-difference time-domain simulation of ground penetrating radar on dispersive, inhomogeneous, and conductive soils
A three-dimensional (3-D) time-domain numerical scheme for simulation of ground penetrating radar (GPR) on dispersive and inhomogeneous soils with conductive loss is described. The finite-difference time-domain (FDTD) method is used to discretize the partial differential equations for time stepping of the electromagnetic fields. The soil dispersion is modeled by multiterm Lorentz and/or Debye m...
متن کاملScattered Field Fdtd Formulations for Debye Dispersive Media
Astract ---New implementation of scattered field FDTD formulations of dispersive material are employed yielding accurate and mathematically compact procedures. This work is based on the application of the Z-transform on the Debye model representing the dispersion in conjunction with the relation between the electric field and the displacement current. The result is an approximate frequency doma...
متن کامل