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Applied aspects of the high-frequency Drude—Sommerfeld model…

Engineering Journal: Science and Innovation

# 12·2017 9

Applied aspects of the high-frequency Drude—Sommerfeld

model for describing field scattering on finite targets

in problems of steady-state vibration theory

© V.F. Apeltsin

Bauman Moscow State Technical University, Moscow, 105005, Russia

Inverse problems of diffraction theory and wave propagation are most important for re-

al-world engineering applications. Huygens’ Principle forms the basis for mathematical

models of such problems. This principle, taken as a physical model of scattered field for-

mation in the problems of electromagnetic (or acoustic) wave scattering on finite targets,

assumes that the scattered field is generated by currents that the initial excitation field

induces over the scattered surface or in its bulk, or, in a general case, along each param-

eter discontinuity boundary in a medium. This secondary field coupled with the excitation

one ensures fulfilment of boundary conditions. In this case the scattered field generally

propagates transversally to the surfaces listed above.

In practice, all direct methods of obtaining approximate numerical solutions to this type

of boundary problems employ Huygens’ Principle to construct mathematical models of

wave phenomena. This concerns the integral equation method (surface or volumetric),

methods of auxiliary currents, of non-orthogonal series, and various modifications of fi-

nite element methods. Nevertheless, this approach has its drawbacks: slow convergence

in the high-frequency region, the problem of Raleigh representation of scattered field in

external boundary problems, and considerable difficulties in deriving an acceptably ac-

curate numerical solution for a model containing dielectric layers with thicknesses much

smaller than the wavelength.

We show that the Sommerfeld method, or its generalization for the case of targets differ-

ent from a circle (a sphere), makes it possible to solve the problems outlined above and

ensure explicit solutions for the high-frequency case. In particular, when synthesizing ra-

diation-absorbent aircraft coating, it can yield an equation determining its permittivity,

and it can also describe a new optical effect in an illuminated area that may lead to cre-

ating a device for nondestructive control of thin synthetic film parameters.

Keywords

: Huygens’ principle, electromagnetic waves, diffraction, asymptotics, Sommer-

feld method, Keller's equations, anti-reflection optical coating principle

REFERENCES



Makarov A.M., Luneva L.A., Makarov K.A.

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Makarov A.M., Luneva L.A., Makarov K.A.

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

Apeltsin V.F.

Inzhenernyy zhurnal: nauka i innovatsii — Engineering Journal:

Science and Innovation

, 2012, issue 2. DOI: 10.18698/2308-6033-2012-2-36.



Apeltsin V.F., Mozzhorina T.Yu.

Matematicheskoe modelirovanie i chislennye

metody — Mathematical Modeling and Computational Methods

, 2014, no. 2,

pp. 3–27.



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