Diffraction of a Transverse Electric (TE) X-Wave by Conducting Objects

Abstract

A study of the diffraction and scattering of a transverse electric X-wave by conducting bodies is presented based on the timedomain, uniform theory of diffraction method and the pulsed plane wave representation of an X-wave. The latter allows the calculation of the diffraction and scattering of each pulsed plane wave component of the incident X-wave at the observation point. The superposition of the individual diffracted and scattered pulsed plane wave components yields the diffracted and scattered field due to an incident X-wave. First, the scattering from a perfectly conducting infinite wedge is studied. Then, the case of a circular conducting disk is considered as an example of a finite scatterer. Numerical results illustrating the effectiveness of the approach, as well as an estimate of the limits of its applicability, are provided.

A Time Domain Incremental Theory of Diffraction: Scattering of Electromagnetic Pulsed Plane Waves

“…In an earlier study of the scattering of an TE X-wave pulse from a circular disk, an approach based on the time-domain uniform theory of diffraction (TD-UTD) was used [21]. However, the derived TD-UTD solutions of the disk problem had some drawbacks, namely, the existence of field singularities at the caustics and the limitation of the diffracted fields to the Keller's diffraction cone [22].…”

“…[19]. Defining the variable (21), one obtains the time-domain shadow-boundary-line and the time domain diffracted elementary amplitudes of the scattered field, respectively. The total time-domain field can be obtained by combining these two parts with the physical optics part, given in Eq.…”

Scattering of X-Waves from a Circular Disk Using a Time Domain Incremental Theory of Diffraction

“…To determine the effectiveness of using localized waves in the aforementioned applications, one has to study the scattering and diffraction of such pulses. In earlier work [16,17], the diffraction of an electromagnetic X-wave by a perfectly conducting infinite wedge has been studied using the uniform theory of diffraction (UTD) [18,19]. The results of that analysis have been extended to the scattering of an X-wave from a conducting circular disk [16,17].…”

“…In earlier work [16,17], the diffraction of an electromagnetic X-wave by a perfectly conducting infinite wedge has been studied using the uniform theory of diffraction (UTD) [18,19]. The results of that analysis have been extended to the scattering of an X-wave from a conducting circular disk [16,17]. Although features of the scattered field calculated using the UTD appear to be quite acceptable, such an approach presents difficulties; specifically, the appearance of singularities at caustics and the formation of cylindrical diffracted wavefronts in the far field region [16,17].…”

Hybridization of Simulation Codes Based on Numerical High and Low Frequency Techniques for the Efficient Antenna Design in the Presence of Electrically Large and Complex Structures

“…Specifically, low frequency (LF) techniques such as finite element method (FEM) [4], finite difference time domain (FDTD) [5] and method of moment (MoM) [6] have been shown suitable to analyze the small scale interactions within the antenna structure, but are not effective to analyze the large scale propagation problems due to the limitation of computational power. On the other hand, however, high frequency (HF) techniques [7][8][9] such as uniform geometrical theory of diffraction (UTD) [7], physical-optics method [10,11], other diffraction or scattering methods [12][13][14][15][16] are capable of analyzing large scale propagation problems in the presence of electrically large and complex structures by using ray tracing techniques, but are not capable of analyzing the small scale interactions within the antenna because of the difficult ray tracing to achieve accurate results. Thus an effective approach to hybridize the high and low frequency techniques and create an useful tool may significantly assist the engineers to resolve this design problem.…”