THE NUMERICAL MODELING OF ELECTROMAGNETIC WAVES BASED ON THE IMPROVED UPML ABSORBING BOUNDARY CONDITION
Wei Lijun1, Zhang Bin2, Chen Zhikang3
1. Department of Electrical Engineering, Hunan Railway Professional Technology College, Zhuzhou 412001, Hunan, China;
2. School of Geosicences and Info-Physics, Central South University, Changsha 410083, China;
3. Hunan Yong Long Highway Construction Development Co., LTD, Yongshun 416700, China
The split Perfectly Matched Layer (PML) Absorbing Boundary Condition (ABC) accomplished the absorption of nonphysical reflections, preliminarily realized the numerical modeling of open infinite space to the finite area, however, on the edge of the ABC area, the field component in calculation need to be split, which will increasing the number of independent equations and the calculation capacity in Maxwell's equations. The Uniaxial-anisotropic Perfectly Matched Layer (UPML) boundary conditions do not need to split the field component, and the iterative formula is easy convenient to programming, except to the decay parameters in the conventional UPML, another two real variable factors are introduced, which is exclusively for the reflections of low frequency. The TMZ wave equations of improved UPML is deduced, the dielectric parameter distribution mode is given, and the program implementation steps of the algorithm was introduced in detail,then the merits were verified by a numerical modeling example of electromagnetic waves, with the split PML, the conventional UPML and the improved UPML boundary conditions, respectively, by comparing the absorption effect from the aspects of the snapshots, and the time domain reflection errors and the frequency domain reflection errors, the results show that the improved UPML boundary condition possess an apparent advantage over absorbing the low frequency reflections in the latter period of the wave propagation, which is more realistically simulates the infinite and open space with little truncation.
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