DocumentCode :
844791
Title :
Accurate Physical Modeling of Discretization Error in 1-D Perfectly Matched Layers Using Finite-Difference Time-Domain Method
Author :
López-Villegas, José María ; Vidal, Neus
Author_Institution :
Electron. Dept., Univ. of Barcelona, Barcelona
Volume :
56
Issue :
9
fYear :
2008
Firstpage :
2076
Lastpage :
2085
Abstract :
In this paper we present an accurate physical model of discretization error in a 1-D perfectly matched layer (PML) using the finite-difference time-domain method. The model is based on the concept of the discrete wave impedance of the PML. This concept implies that the wave impedance in the discretized space changes, with respect to the continuous value, when absorption occurs. These changes depend on the absorption per unit length, as well as on the discretization step. In the discretized space, both, the magnitude and phase of wave impedance are modified. We employ numerical simulations obtained using a 1-D code to test the proposed model. We then compare the results with those obtained from coaxial wave guide geometry using a commercial 3-D software package. One important consequence of this modeling scheme is the feasibility of the PML without return losses due to discretization error. In practice, numerical results show that by correctly adjusting the electromagnetic parameters of the PML (electric permittivity and magnetic permeability), a significant improvement in the reflection characteristics is obtained. In some cases, it could be as much as 78 dB. The remaining return losses are successfully explained as second-order effects related to the discontinuity of electromagnetic parameters at the interface between the simulation space and PML.
Keywords :
coaxial waveguides; electric impedance; finite difference time-domain analysis; magnetic permeability; permittivity; 1D perfectly matched layers; 3D software package; coaxial waveguide geometry; discrete wave impedance; discretization error; electric permittivity; electromagnetic parameters; finite-difference time-domain method; magnetic permeability; numerical simulations; Absorbing boundary conditions; discrete wave impedance; discretization error; finite-difference time-domain (FDTD) methods; perfectly matched layer (PML);
fLanguage :
English
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9480
Type :
jour
DOI :
10.1109/TMTT.2008.2002231
Filename :
4607252
Link To Document :
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