Search

A new expression of a Gaussian beam derived by using a spectral domain method is applied to the scattering problem from a hemispherical boss on a conducting plane. On the method of images, the original problem is reduced to that of the scattering of two Gaussian beams by a full sphere. 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 difference between the bistatic radar cross section of a Gaussian beam and that of a plane wave is discussed. Index Terms--Boss, Gaussian beam, radar cross section (RCS), scattering.

The near-field distribution in the case of the normal incidence to the Luneberg lens reflector is numerically obtained by using the modal expansion technique and point-matching method. As a model of the Luneberg lens, six different homogeneous media is used. A microwave experiment was also performed. Index Terms - Electromagnetic scattering, Luneberg lens reflector, microwave experiment, point-matching method.

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 Kozaki's 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.

For purpose of finding the dielectric constant, a new expression of the beam scattering is obtained by using the boundary element method (BEM) with extended boundary conditions. Comparision between with and without resonant condition was made for total scattered power. To find the accuracy, convergence property of the total scattered power versus divided number has been examined. To check the boundary conditions at the corner of the scatter, the electric field difference between inner and outer side has also been calculated and confirmed. Total electric field distributions in space are illustrated for the plane and beam wave. Microwave experimented was also performed. Index Terms--Boundary element method, dielectric rectangular cylinder, Gaussian beam.

This paper describes exactly a new formulation of the T-matrix method with R-matrix expression for the electromagnetic diffraction efficiency about a case that the dielectric-coated metallic Fourier grating is illuminated by a plane wave. We show that the parameters of numerical calculations are widely applied by using R-matrix expression for the thick dielectric coating although this formulation is restricted for groove depth of the grating in a conventional T-matrix method. [ABSTRACT FROM AUTHOR]