Antenna Gain and Link Budget for Waves Carrying Orbital Angular Momentum (OAM)

This paper addresses the RF link budget of a communication system using unusual waves carrying an orbital angular momentum (OAM) in order to clearly analyse 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 polarisation, 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.Comment: 33 pages, 11 figure

Non-thermal plasma potentialities for microwave device reconfigurability

Three examples of results achieved from cooperative works with microwave and plasma research groups in Toulouse (France) are presented in this paper. They are focused on the use of few non-thermal plasmas to make a microwave device reconfigurable. The relative permittivity of such a plasma medium can be tuned from unity to negative values. This special feature appears to be very attractive, although the electromagnetic losses are significant. The use of plasmas with planar waveguides and within metamaterials is discussed. In addition, the basic principles of a scanning antenna built with a leaky wave in a plasma layer are presented

Axially Localized Waves carrying Orbital Angular Momentum : Physics, emitters and Radio-links limitations

International audienc

Modélisation de la propagation d'une onde électromagnétique sur des scènes de grande taille par résolution de l'équation parabolique 3D vectorielle

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Modélisation de la propagation d'une onde électromagnétique sur des scènes de grande taille par résolution de l'équation parabolique 3D vectorielle

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Modélisation par la méthode des faisceaux gaussiens vectoriels et multimodes de l'interaction d'une onde électromagnétique avec un diélectrique épais ou un réflecteur métallique/

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Applications du formalisme des faisceaux gaussiens à la modélisation de l'interaction d'une onde électromagnétique avec un objet 3D complexe

TOULOUSE3-BU Sciences (315552104) / SudocSudocFranceF

Leaky-wave plasma antenna with tunable radiation angle

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3D interaction of Gaussian beams with dichroic surfaces for the modeling of quasi-optical systems

International audienceIn quasi-optical systems, dichroic surfaces are used to split, filter, or mix signals. Such surfaces cannot be modeled by existing Gaussian-beam methods. In this article we propose a technique to model the interaction of a Gaussian beam (GB) with a dichroic surface based on a matching in the spectral domain. For a GB illumination of the surface, the reflected and transmitted fields are approximated by one reflected and one transmitted Gaussian beams. Their characteristics are determined by means of the spectral matching through a second-order approximation of the dichroic surface response when excited by plane-waves. Numerical experiments and comparisons with reference solutions show the efficiency of the method in terms of accuracy and computation time