Computation of electromagnetic scattering by multilayer dielectric objects using Gaussian beam based techniques

Abstract

This article aims to evaluate the abilities of Gaussian beam techniques to compute the interaction between an electromagnetic field and a multilayer dielectric object. First, we propose an approach to expand a field on a set of elementary Gaussian beams from a curved surface. Then, we study two techniques to compute the interaction: a Gaussian beam shooting and bouncing algorithm and another original approach using the Gaussian beam transmission and reflection coefficients. We analyse the advantages (rapidity/accuracy) of these two techniques with respect to a conventional approach to compute the radiation of an antenna protected by a radome.

Electromagnetic Scattering of a Field Known on a Curved Interface Using Conformal Gaussian Beams

“…A multi-beams summation can been applied in three-dimensional problems to expand electric and magnetic currents on a curved interface into elementary Gaussian currents as done in the twodimensional case [17]. With the analytical plane-wave spectrum of a CGB and using the Fresnel coefficients, a closed-form calculation of the reflected and transmitted fields by a mono or multi dielectric layers curved interface is possible as realised in [13]. These will be presented in future communications.…”

“…In this section, we briefly present an extension of the CGB to the three-dimensional case. More details about CGB can be found in [13,17].…”

“…We first assume that the electric and magnetic fields are known on a curved surface S. Equivalent electric J and magnetic M currents are then given by the Equivalence Theorem on S. As presented in [13], the basic idea is to expand the surface-currents J, M using Gaussian amplitude currents:…”

“…A comparison with a numerical evaluation of the PWS is presented. The PWS of a CGB will able one to express the interaction between fields and dielectric interfaces as done in [13]. In Section 4 we derive the analytical farfield of a CGB.…”

“…Gaussian Beams Tracking (GBT) methods are based on the ability to expand any source fields into a summation of Gaussian beams [11,12]. During the last years, GBT has been successfully applied to the computation of the fields scattered by mono and multilayer dielectric radomes [13,8]. Recently, it has been applied to the Airbus A380 front antenna radome, reducing computation time by a factor 70 in contrast with a classic Plane-Wave Spectrum (PWS) based method [14].…”