I.Yu. Bratukhin1, A.F. Kryachko2, G.M. Revunov3

1–3 St. Petersburg State University of Aerospace Instrumentation (St. Petersburg, Russia)

1 Avtomatika Concern (St. Petersburg, Russia)

1 bratukhinY@ya.ru, 2 alex_k34.ru@mail.ru, 3 revunpank@gmail.com

Indirect methods for estimating the parameters of materials and structures are based on various physical phenomena. By nature, they are divided into mechanical, electromagnetic, spectral resonance, capillary phenomena, etc., while the degree of correlation of material parameters and the contrast of the manifestation of certain phenomena will determine the effectiveness of their assessment. The most suitable methods of material analysis are microwave or ultrahigh frequency methods, allowing to achieve high resolution of defect localization and accuracy of estimation of material parameters at moderate cost and hardware costs. The purpose of the work is to investigate ways to increase the effectiveness of means for estimating the parameters of inhomogeneous media according to the known distribution of the scattered electromagnetic field.

An analysis of the mathematical approach to the description of non-planar waves is carried out, which consists in decomposing the field emitted by an elementary source into a basis corresponding to plane waves. It is shown how this distribution changes in the presence of such media. The problem of numerical calculation of Sommerfeld-type integrals, as well as integrals for determining the Green function of planar multilayer structures containing singularities, is considered. It is revealed that at certain parameter values, these integrals can acquire the character of rapidly oscillating and weakly damping functions. The method of complex sources was used to calculate the Green function of multilayer structures. By numerically solving the direct scattering problem, it is shown that the extreme values in the scattering diagram of a point source decrease with significant heterogeneity compared with a homogeneous dielectric layer. The presented results confirmed that the most effective method of numerically finding the field from a point source in a flat layered medium is the method of complex sources of the medium, which avoids problems with the numerical integration of integrals in the Sommerfeld integral.

Bratukhin I.Yu., Kryachko A.F., Revunov G.M. Study of electromagnetic wave scattering of elementary sources from an inhomogeneous layer in nondestructive testing problems. Achievements of modern radioelectronics. 2024. V. 78. № 8. P. 56–68. DOI: https://doi.org/10.18127/j20700784-202408-09 [in Russian]

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