A class of analytical absorbing boundary conditions originating from the exact surface impedance boundary condition

2003 ◽  
Vol 51 (2) ◽  
pp. 560-563 ◽  
Author(s):  
M.K. Karkkainen ◽  
S.A. Tretyakov
Keyword(s):  
Boundary Condition ◽  
Boundary Conditions ◽  
Surface Impedance ◽  
Absorbing Boundary Conditions ◽  
Impedance Boundary Condition ◽  
Absorbing Boundary ◽  
Impedance Boundary

scholarly journals FDTD modeling of nonperiodic antenna located above metasurface using surface impedance boundary condition

2019 ◽  
Vol 6 ◽  
pp. 17
Author(s):  
Toru Uno ◽  
Takuji Arima ◽  
Akihide Kurahara
Keyword(s):  
Boundary Condition ◽  
Surface Impedance ◽  
Fdtd Method ◽  
Dipole Antenna ◽  
Point Sources ◽  
Impedance Boundary Condition ◽  
Computational Error ◽  
Impedance Boundary ◽  
Scanning Method ◽  
Computational Resources

This paper investigates an FDTD modeling method for precisely calculating the characteristics of a single, that is, a nonperiodic antenna located above a metasurface that consists of an infinite periodic conducting element on a flat dielectric substrate. The original FDTD method requires enormous computational resources to analyze such structures because an appropriate periodic boundary condition (PBC) is not supported, and a brute force approach has to be used for this reason. Another option is to use the array scanning method in which a single source is synthesized from a superposition of infinite phased array of point sources. In this method, some problems such as a mutual coupling between the single antenna and the metasurface, a computational error contained in a numerical integration over the Brillouin zone and so on have not been resolved yet. In order to resolve these difficulties and to reduce computational resources, a surface impedance boundary condition (SIBC) is incorporated into the FDTD method in this paper. The validity of the method is numerically confirmed by calculating an input impedance and a radiation pattern of a horizontal dipole antenna located above the metasurface.

Absorbing boundary conditions for acoustic media

Geophysics ◽  
1985 ◽  
Vol 50 (6) ◽  
pp. 892-902 ◽  
Author(s):  
R. G. Keys
Keyword(s):  
Boundary Condition ◽  
Differential Operator ◽  
Boundary Conditions ◽  
Plane Waves ◽  
Basic Element ◽  
Absorbing Boundary Conditions ◽  
Boundary Operator ◽  
Order Differential Operator ◽  
Absorbing Boundary ◽  
Boundary Operators

By decomposing the acoustic wave equation into incoming and outgoing components, an absorbing boundary condition can be derived to eliminate reflections from plane waves according to their direction of propagation. This boundary condition is characterized by a first‐order differential operator. The differential operator, or absorbing boundary operator, is the basic element from which more complicated boundary conditions can be constructed. The absorbing boundary operator can be designed to absorb perfectly plane waves traveling in any two directions. By combining two or more absorption operators, boundary conditions can be created which absorb plane waves propagating in any number of directions. Absorbing boundary operators simplify the task of designing boundary conditions to reduce the detrimental effects of outgoing waves in many wave propagation problems.

Mixed surface impedance boundary condition for FDTD simulations

2017 ◽  
Vol 11 (9) ◽  
pp. 1197-1202 ◽  
Author(s):  
Yunlong Mao ◽  
Atef Z. Elsherbeni ◽  
Tao Jiang ◽  
Si Li
Keyword(s):  
Boundary Condition ◽  
Surface Impedance ◽  
Impedance Boundary Condition ◽  
Impedance Boundary ◽  
Fdtd Simulations
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