Programa del congreso

In this paper, we propose an analytical circuit approach for the analysis and design of 3D metagratings formed by periodic arrangements of rectangular waveguides (RWG) perfored with lateral slot insertions. The analytical circuit is based on a Floquet-Bloch expansion of the electromagnetic field and integral-equation methods. With the present approach, physical insight is given to the complex scattering and diffraction phenomena, even under oblique-incidence conditions. Furthermore, the analytical circuit is computationally efficient compared to full-wave solutions. Interestingly, the present 3D metagrating shows independent polarization control of the two orthogonal states. Thus, it can be utilized for the efficient design of microwave and mm-wave devices, such as full-metal polarizers, of potential interest for future communications systems.

In this paper we propose an analytical method based on Floquet circuits to simulate complex time-varying scenarios. The model gives physical insights to understand the diffraction phenomena caused by a the interaction of a plane wave with screen switching periodically from ``air'' to ``metal'' states and viceversa. Several variables such as ``duty cycle'' or ``modulation ratio'' have been established to modify and control the diffraction pattern along a time variable denominated ``macroperiod''. The results have been compared with a finite-difference time-domain (FDTD) method showing close behaviours, validating the proposed approach.

A complete formulation for the calculation of infinite periodic structures by applying the Combined Integral Equation (CFIE) and Discontinuous Galerkin (DG) is presented. The study of periodic structures involves complex multiscale geometries formed by different surfaces and materials. This complexity when designing the models can be softened by having the possibility of meshing each of the surfaces independently, making this proposed method suitable for the analysis of this type of structures. It is worth mentioning the possibility of solving problems involving elements of infinite dimensions, taking into account only a section of the element that fills the unit cell to be analysed and without the need to adjust the meshing at the edges to guarantee its symmetry, reducing the complexity in the design of the models and offering a more precise solution with a much lower computational cost.

In this paper, it is designed a metasurface capable of reducing the monostatic radar cross section in a considerable bandwidth (52.4%) within the X-band (8.2-12.4GHz). The combination of two unit cells results in a structure that achieves a reduction below -10 dB between 8.6 GHz and 10.8 GHz. Moreover, the unit cells are designed to be scalable to the frequency band of interest. As they are very sensitive to frequency, parametric studies have been carried out during the design to optimize the metasurface behavior and it has been proven that its size can be increased by replicating the structure according to the requirements, while maintaining its response. In addition, a study of the phase of the 𝑺𝟏𝟏 parameter is performed, which verifies this bandwidth by obtaining a phase difference of 180º

Micromag develops Radar Absorbing Materials based on three pillars: simulation of electromagnetic behavior, manufacturing of specific additives and composite materials, and material characterization measurements. In the first point, Micromag has internally developed simulation tools that allow: predicting the impact of the inclusion of additives in matrices, designing multilayer materials considering polarizations or angles of incidence in both R and T, a database with more than 5000 characterized materials to contrast simulations against experimental measurements, optimization of designs against specific requirements. In the second point, Micromag designs and manufactures additives which are processed to integrate them into different matrices such as resins, paints, foams, plastics or elastomers, adjusting to the specific requirements of each application. In the third point, Micromag has developed different software and measurement systems that allow the characterization of materials with a wide range of geometries and sizes, from waveguide characterization to portable measurement systems.

El análisis de dispersión de estructuras periódicas selectivas en frecuencia (FSS) o en polarización (PSS) compuestas por celdas unidad basadas en guía de onda puede acometerse desde una perspectiva de análisis modal como el Mode-Matching (MM). Las aproximaciones existentes para la hibridación mediante esta técnica usando modos de Floquet y el método de los elementos finitos bidimensional (FEM-2D) están basadas en una representación de onda completa de los campos y no consideran mejoras de eficiencia para barridos en frecuencia de banda ancha, un caso típico de aplicación. En este artículo se presenta una aproximación alternativa directamente derivada de potenciales escalares, que es además independiente de la frecuencia en todos los pasos previos a la obtención de la matriz de dispersión generalizada. Se ha formulado para ángulos incidentes normales al plano de periodicidad, típicamente los primeros considerados en el flujo de diseño de estas estructuras.