Wave Propagation in Periodic Metallic Structures with Equilateral Triangular Holes

This paper studies wave propagation in a periodic parallel-plate waveguide with equilateral triangular holes. A mode-matching method is implemented to analyze the dispersion diagram of the structure possessing glide and mirror symmetries. Both structures present an unexpected high degree of isotropy...

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Detalles Bibliográficos
Autores: Alex Amor, Antonio, Valerio, Guido, Ghasemifard, Fatemeh, Mesa Ledesma, Francisco Luis, Padilla, Pablo, Fernández González, José M., Quevedo Teruel, Óscar
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/97796
Acceso en línea:https://hdl.handle.net/11441/97796
https://doi.org/10.3390/app10051600
Access Level:acceso abierto
Palabra clave:Metasurfaces
Periodic structures
Equilateral triangular holes
Mode-matching
Dispersion analysis
Glide symmetry
Mirror symmetry
Isotropy
Descripción
Sumario:This paper studies wave propagation in a periodic parallel-plate waveguide with equilateral triangular holes. A mode-matching method is implemented to analyze the dispersion diagram of the structure possessing glide and mirror symmetries. Both structures present an unexpected high degree of isotropy, despite the triangle not being symmetric with respect to rotations of 90 . We give some physical insight on the matter by carrying out a modal decomposition of the total field on the hole and identifying the most significant modes. Additionally, we demonstrate that the electrical size of the triangular hole plays a fundamental role in the physical mechanism that causes that isotropic behavior. Finally, we characterize the influence of the different geometrical parameters that conform the unit cell (period, triangle size, hole depth, separation between metallic plates). The glide-symmetric configuration offers higher equivalent refractive indexes and widens the stopband compared to the mirror-symmetric configuration. We show that the stopband is wider as the triangle size is bigger, unlike holey structures composed of circular and elliptical holes where an optimal hole size exists.