Tah J. Park

Analysis of TM scattering from finite rectangular grooves in a conducting plane

TM-wave scattering from rectangular grooves in a perfectly conducting plane is investigated. A Fourier-transform technique is employed to express the scattered field in the spectral domain as a superposition of the parallel-plate waveguide modes. The boundary conditions are enforced on the conducting surface and the groove apertures to obtain simultaneous equations for the transmitted field inside the grooves. The simultaneous equations are solved to obtain the transmitted field in a series representation that reduces to a closed form in a high-frequency scattering regime. With the use of the stationary phase approximation, the far-zone scattered field is obtained, and its scattering behavior is studied in terms of the scattering angle. The diffraction efficiency for the finite grating as the number of grooves increases is presented.

An analysis of transverse electric scattering from a rectangular channel in a conducting plane

The problem of transverse electric plane wave scattering from a rectangular channel which is engraved in a perfect conducting plane is investigated. A Fourier transform technique is employed to express the scattered field in the spectral domain in terms of parallel-plate waveguide modes. The boundary conditions are enforced on the conducting surface and the channel aperture to obtain simultaneous equations for the transmitted field inside the channel. The simultaneous equations are solved to represent the transmitted field in a series form. By using the stationary phase approximation, the exact expression for the far-zone scattered field is obtained and the echo width behavior is numerically studied in terms of the scattering angle, frequency, and channel size. It is found that the behavior of the echo width versus the channel depth exibits resonance irrespective of the size of the channel width. An approximate series expression (Kirchhoff solution) for the echo width is valid for high-frequency scattering regimes (a > 2 λ). We also present an approximate closed form solution for nadir backscattering which is valid when a > 0.2λ.

An analytic solution for transverse‐magnetic scattering from a rectangular channel in a conducting plane

The problem of transverse‐magnetic plane‐wave scattering from a rectangular channel in a perfect conducting plane is investigated. A Fourier‐transform technique is employed to express the scattered field in the spectral domain in terms of parallel‐plate waveguide modes. An approximate series solution for scattering is presented in a closed form that is valid for a high‐frequency scattering regime. The presented formulation is computationally much more efficient than other existing numerical solutions.

TE scattering from a slit in a thick conducting screen: revisited

TE plane-wave scattering from a slit in a thick conducting screen is reexamined. The boundary conditions are enforced to obtain simultaneous equations for the transmitted field inside the thick conducting screen. The simultaneous equations are solved to represent the transmitted and scattered fields in series forms. An approximate series solution for transmission is obtained in closed form which is valid for the high-frequency scattering regime. >

Gaussian beam scattering from a semicircular boss above a conducting plane

Electromagnetic scattering of a Gaussian beam from a semicircular boss which protrudes above a conducting plane is investigated. The theoretical analysis for scattering is based on Kozakis approximation, which makes it possible to express the Gaussian beam as a product of plane wave and weight function results. The scattered fields are expressed in simple closed forms which are valid when the diameter of the boss is comparable to or less than the Gaussian beamwidth. The numerical computations are performed to find that the angular bistatic RCS (radar cross section) of the Gaussian beam is much broader in scattering pattern than the plane wave case. >

Surface wave scattering from a notch in a dielectric-covered ground plane: TE-mode analysis

026The problem of TE mode surface wave scattering from a rectangular notch in a dielectric-covered ground plane is considered. A Fourier-transform technique is used to express the scattered field in the spectral domain in terms of parallel-plate waveguide modes. The boundary conditions are enforced on the ground plane and the notch aperture to obtain simultaneous equations for the transmitted field inside the notch. The simultaneous equations are solved to obtain a solution in a fast convergent series, thus facilitating the numerical computation. The transmission, reflection, and scattering coefficients are found to oscillate as the notch width increases especially when the notch depth is comparable to and larger than one wavelength. A limited number of computations show that the reflected power loss is less than 2% when the notch width is less than one wavelength. >

TE-scattering and reception by a parallel-plate waveguide array

TE-wave scattering and reception by a parallel plate waveguide array is Investigated. A Fourier-transform technique is used to express the scattered field in the spectral domain. The boundary conditions are enforced on the conducting surface and the array apertures to obtain simultaneous equations for the transmitted field inside the waveguide. The simultaneous equations are solved to obtain the transmitted field in a series representation whose first term is the Kirchoff solution. The behavior of the far-zone scattered field and the transmission coefficient are studied in terms of the scattering angle, array size, and frequency. >

TM-scattering from a rectangular channel in a conducting plane

Transverse magnetic (TM) plane-wave scattering from a rectangular channel engraved in a perfectly conducting plane is investigated. A Fourier-transform technique is employed to express the scattered field in the spectral domain in terms of parallel-plate waveguide modes. An approximate series solution for scattering is presented in a closed-form which is valid for the high-frequency scattering regime. Approximate solutions which are valid for the quasi-static and low-frequency scattering regimes are also obtained. Using the stationary phase approximation, the far-zone scattered field is obtained and its scattering behavior is studied in terms of the scattering angle, frequency, and channel size.<<ETX>>