Projeto e análise de metasuperfícies condutoras magnéticas artificiais utilizando condições de contorno generalizadas

Abstract

Two-dimensional structures whose characteristics can be designed to obtain advantageous and unusual electromagnetic properties are called metasurfaces. These structures have several applications in the control of electromagnetic waves and among them artificial magnetic conductor (AMCs) metasurfaces have been widely used, especially in the context of antennas. These structures are commonly designed using methods based on analytical expressions or optimization techniques, leading to limitations in terms of flexibility of geometries and computational cost, respectively. Such limitations also occur in metasurface performance analysis, since the conventional method of calculating the characterization parameters depends on computer simulation of the various incidence conditions. This work presents the application of the generalized boundary conditions (GBCs) in the design and analysis of AMC metasurfaces, aiming to reduce the limitations presented by conventional methods, from the representation of the electromagnetic surface by the superficial electric and magnetic susceptibilities. For this purpose, the main concepts related to the artificial magnetic conductors and the GBCs are presented, as well as the description of the steps and equations necessary to apply the method in the design and analysis of AMC metasurfaces. The functionality of the proposed design method in obtaining AMCs with four different metallic scatterers geometries (square, square ring, Jerusalem cross and Sierpinski Carpet fractal), is evaluated in two cases with different dielectric substrates using the commercial software High Frequency Structure Simulator - HFSS for simulation, presenting reduced computational cost and AMC behavior in all analysed cases. In addition, the performance of the designed AMCs is evaluated for operating bandwidth, angular and polarization stability, and as printed antenna reflectors. The development of equations that relate the characterization parameters of the AMCs to the surface susceptibilities of the GBCs model is also presented, enabling a qualitative and quantitative metasurface evaluation in a fast way.