Diffraction by 90° penetrable wedges with finite conductivity

Area of Science:

• Electromagnetics and Wave Propagation
• Diffraction Theory
• Computational Electromagnetics

Background:

• The diffraction of electromagnetic waves by sharp edges is a fundamental problem in electromagnetics.
• Existing high-frequency methods often have limitations regarding material properties or geometric configurations.
• Accurate solutions are crucial for applications in antenna design, radar scattering, and microwave engineering.

Purpose of the Study:

• To develop a high-frequency analytical solution for plane wave diffraction by a 90° wedge composed of a penetrable material with finite conductivity.
• To derive closed-form expressions for the diffraction coefficient applicable to both the interior and exterior regions of the wedge.
• To validate the proposed solution against numerical methods for various material loss tangents.

Main Methods:

• Utilizing a physical optics approximation for equivalent electric and magnetic surface currents.
• Employing uniform asymptotic evaluations of radiation integrals.
• Deriving the diffraction coefficient using the uniform theory of diffraction (UTD) and Fresnel coefficients.

Main Results:

• Closed-form expressions for the diffraction coefficient were obtained.
• The solution is valid for any loss tangent of the material.
• The proposed method effectively calculates diffracted fields in both inner and outer wedge regions.
• Comparisons with numerical tools confirmed the accuracy of the analytical solution.

Conclusions:

• The physical optics approximation combined with uniform asymptotic evaluation provides an effective high-frequency solution for the 90° wedge diffraction problem.
• The derived diffraction coefficients are accurate and broadly applicable, without limitations on material loss.
• This work offers a valuable analytical tool for analyzing electromagnetic wave scattering in complex environments.