Ray-Tracing Model for Generalized Geodesic-Lens Multiple-Beam Antennas

Geodesic-lenses are a compelling alternative to traditional planar dielectric lens antennas, as they are low loss and can be manufactured with a simple mechanical design. However, a general approach for the design and analysis of more advanced geodesic-lens antennas has been elusive, limiting the av...

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Detalles Bibliográficos
Autores: Liao, Qingbi, Fonseca, Nelson J. G., Camacho Aguilar, Miguel, Palomares Caballero, Ángel, Mesa Ledesma, Francisco Luis, QuevedoTeruel, Óscar
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/148933
Acceso en línea:https://hdl.handle.net/11441/148933
https://doi.org/10.1109/TAP.2022.3233643
Access Level:acceso abierto
Palabra clave:Geodesic-lenses
Lens antennas
Non-euclidean transformation optics
Parallel plate waveguides (PPWs)
Ray tracing
Descripción
Sumario:Geodesic-lenses are a compelling alternative to traditional planar dielectric lens antennas, as they are low loss and can be manufactured with a simple mechanical design. However, a general approach for the design and analysis of more advanced geodesic-lens antennas has been elusive, limiting the available tools to rotationally symmetric surfaces. In this article, we present a fast and efficient implementation built on geometrical optics and scalar diffraction theory. A numerical calculation of the shortest ray path (geodesic) using an open-source library helps quantify the phase of the electric field in the lens aperture, while the amplitude is evaluated by applying ray-tube power conservation theory. The Kirchhoff-Fresnel diffraction formula is then employed to compute the far field of the lens antenna. This approach is validated by comparing the radiation patterns of a transversely compressed geodesic Luneburg lens (elliptical base instead of circular) with the ones computed using commercial full-wave simulators, demonstrating a substantial reduction in computational resources. The proposed method is then used in combination with an optimization procedure to study possible compact alternatives of the geodesic Luneburg lens with size reduction in both the transverse and vertical directions.