Electromagnetic scattering by a circular cavity of arbitrary shape placed in a perfect electric conductor

Abstract

An efficient modal expansion technique for scattering by a circular cavity with an arbitrary arc in a perfect electric conductor is developed. In contrast to the existing methods proposed for a shallow or semi‐circular cavity, the proposed method can be utilised for a circular cavity of arbitrary shape while is computationally efficient. The authors first introduce an auxiliary circular border that divides half‐space above the cavity into two separate subregions. Then, the tangential fields in the two subregions, which satisfy the Helmholtz equation, are expanded in terms of an infinite series of radial wave functions. The fields are matched at the auxiliary border to construct three independent equations in two different coordinate systems. By employing the addition theorem, all equations are transferred into the same coordinate system. Finally, the equations are converted into a system of linear equations and then solved through regular matrix techniques for the expansion coefficients. The solution is verified by the Method of Moments used in FEKO electromagnetic simulation software. This method is employed to study the effects of cavity shape and incident wave polarisation on the scattering signature.

Scattering from a semi‐elliptical cavity with arbitrary orientation placed in a perfect electric conductor plane

“…So far, many studies have been conducted on scattering from open cavities [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The results of these investigations help us to design electromagnetic structures in various applications such as optics, radar cross-section reduction, non-destruction testing, and remote sensing.…”

A Generalized Solution for H-polarized Scattering from Shallow Cavities with an Arbitrary Profile

“…The present method is a semianalytic treatment that uses wavefunction expansion and region matching techniques to provide a closed-form of solution for a shallow cavity with a specified and continuous profile in a Perfect Electric Conductor (PEC) plane. Some studies have been done on shallow circular, elliptical, and triangular cavities [13,19,20]. However, this study focuses on a more general manner to apply more practical and different problems and cavities.…”

Computation of TM Scattered Fields Induced by a Truncated Semi-Elliptic Cavity in a PEC

“…Investigations into scattered waves arising from different objects and cavities offer useful insights for the design of electromagnetic structures used in practical applications, including optics, non-destruction testing, remote sensing, and radar cross section (RCS) reduction. Multiple methods have been proposed for analyzing the scattering of electromagnetic (EM) waves induced by various types of opened cavities, such as rectangular grooves [1][2][3][4][5], circular-arc channels [6][7][8], and triangular grooves [9][10][11].…”