A split-step wavelet method for simulating the long-range wave propagation is introduced. It is based on the fast wavelet transform. Compared to the split-step Fourier method, this method improves the computation efficiency while keeping a good accuracy. The propagation is performed iteratively by means of a pre-computed matrix containing the individual propagations of the wavelets. A fast computation method of this matrix is also presented. For the radiowave propagation in the low troposphere, a local image method is proposed to account for an impedance ground. Inhomogeneous atmospheres and irregular grounds are also considered. Finally, numerical tests of long-range propagations are performed to show the accuracy and time efficiency of this method.
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.
This paper addresses the RF link budget of a communication system using unusual waves carrying an orbital angular momentum (OAM) in order to clearly analyze the fundamental changes for telecommunication applications. The study is based on a typical configuration using circular array antennas to transmit and receive OAM waves. For any value of the OAM mode order, an original asymptotic formulation of the link budget is proposed in which equivalent antenna gains and free-space losses appear. The formulations are then validated with the results of a commercial electromagnetic simulation software. By this way, we also show how our formula can help to design a system capable of superimposing several channels on the same bandwidth and the same polarization, based on the orthogonality of the OAM. Additional losses due to the use of this degree of freedom are notably clearly calculated to quantify the benefit and drawback according to the case.
Abstract-In this article, we propose to apply the Gabor expansion to describe magnetic and electric currents given on a regular curved interface in dimension 2. From this description, we show that the computation of the current radiation can be performed by the introduction of a new kind of gaussian beams. We call them the conformal gaussian beams. Their analytic formulation is obtained using an asymptotic evaluation of the radiation integrals. Their properties are discussed and an application example is presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.