Simple, Compact, and Multiband Frequency Selective Surfaces Using Dissimilar Sierpinski Fractal Elements

Clarissa de Lucena Nóbrega,Adaildo Gomes D’Assunção,Gláucio Lima Siqueira,Marcelo Ribeiro da Silva,Paulo Henrique da Fonseca Silva

doi:10.1155/2015/614780

Abstract

This paper presents a design methodology for frequency selective surfaces (FSSs) using metallic patches with dissimilar Sierpinski fractal elements. The transmission properties of the spatial filters are investigated for FSS structures composed of two alternately integrated dissimilar Sierpinski fractal elements, corresponding to fractal levelsk=1, 2, and 3. Two FSS prototypes are fabricated and measured in the range from 2 to 12 GHz to validate the proposed fractal designs. The FSSs with dissimilar Sierpinski fractal patch elements are printed on RT/Duroid 6202 high frequency laminate. The experimental characterization of the FSS prototypes is accomplished through two different measurement setups composed of commercial horns and elliptical monopole microstrip antennas. The obtained results confirm the compactness and multiband performance of the proposed FSS geometries, caused by the integration of dissimilar fractal element. In addition, the proposed FSSs exhibited frequency tuning ability on the multiband frequency responses. Agreement between simulated and measured results is reported.

Highlights

A periodic surface is basically a set of identical elements arranged two-dimensionally composing an infinite array [1]
In this paper we present a fractal design methodology that aims to achieve simple, compact, and multiband frequency selective surfaces (FSSs) frequency responses using dissimilar Sierpinski fractal metallic patch elements on a single-layer substrate
Simple, compact, and multiband frequency selective surface (FSS) structures were obtained by integrating dissimilar Sierpinski fractal patch elements

Summary

Introduction

A periodic surface is basically a set of identical elements arranged two-dimensionally composing an infinite array [1]. A periodic array composed of conductive patches or aperture elements, acting as a reflecting or transmitting surface, is called frequency selective surface (FSS). One of the main parameters that influence the FSS frequency response is the element shape, that is, its type (patch or aperture) and geometry [1, 2]. Regarding the geometry of the conducting patch element, a FSS array can present many different shapes ranging from Euclidean to fractal geometries. The use of fractal patch geometries as conducting elements on a FSS periodic design has provided superior performance, for some applications, compared to those using typical patch geometries, such as rectangular, square, circular, dipole, cross-dipole, and square loop [1,2,3]. A FSS with high frequency compression factor is referred to as compact. The attractive features of certain self-similar fractals allow the design of selective filters with multiband behavior [6]

Objectives

Results

Conclusion