A Novel Fractal Multi-band Frequency Selective Surface

Abstract

In this paper, a new multiband fractal frequency selective surface (MF-FSS) is proposed. The work presents a new fractal design methodology for FSSs with Swastika fractal patch elements. The proposed MF-FSS includes periodic arrays of metallic patches, printed on a single layer substrate. The structure parametric analysis is carried out in terms of fractal iterations, geometry elements, and unit-cell size. The simple controllable feature of the proposed structure lets us tune the given parameters of FSS geometry to achieve adjustable bandstop filter. The fractal geometry allows us to design compact structures (CP = 54%) that behave like dual-polarized bandstop filters. The designed structure is validated by means of an excellent agreement between the simulation and measurement results. Also, results show the proposed structure presents the most desirable features like fractal compactness, multiband response, dual polarization, excellent angular stability, and controllability. This work presents a fundamental structure that can be applied into the more complex and sophisticated designs in future.

Synthesis of Multiband Frequency Selective Surfaces Using Machine Learning With the Decision Tree Algorithm

“…In both cases, the periodicity is the same because it has little influence on the behavior of the frequency response. Thus, under criteria with Ideal classification, their respective [ , 1 , 2 ] values for each scenario are (in mm) [19, 2.25, 2.75] and [19,2,3].…”

“…Table III shows the limits of the classification parameters used in each algorithm. In both scenarios, under the same criteria, the random forest returned the same tuples: [19, 2.25, 2.75], [19, 2.5, 2.75], [19,2,3].…”

“…In [16] and [17], authors used fractal (Vicsek and Koch, respectively) in the analysis of single resonance frequency band FSS: in [16], authors used a bioinspired algorithm (SSO -Social Spider Optimization), and in [17] a simple numerical method to optimize the bandwidth of two coupled FSSs is reported. In [18] and [19], authors present FSS analysis with a third-level fractal characteristic, modified Jerusalem Cross (triple band) and Swastika (multiband), respectively. In [20], a single-layer FSS with an asymmetric Jerusalem cross patch, and a selfcomplementary aperture is proposed, based on the Babinet's principle.…”

Characterization of the koch fractal hexagonal loop frequency selective surface for X-band application

“…With a higher value of incident angle, the unit cell periodicity should be half the free space wavelength to prevent the occurrence of the grating lobe phenomena-a limitation that can be prevented by implementing a fractal structure to miniaturize the FSS. For example, extensive studies over the past decade have integrated patch or slot elements with the fractal structures such as the Koch fractal structure [3,19], the Minkowski [20] and the Minkowski island [21], the Interdigital fractal structure [22], the Sierpinski fractal structure [23], the Swastika fractal structure [24] etc., to reduce the size of the FSS element.…”

Yüksek İzolasyonlu MIMO Anten Dizisi İçin FSS Duvar Tasarımı

“…Therefore, when an FSS is needed for a new desired transmission band, no additional experiment is required. In literature, several FSS examples are presented using periodic fractal resonant element arrays [7][8][9]. In this study, a new FSS unit cell is designed to reduce the mutual coupling effect caused by surface currents between 2x1 identical array patch antennas with a 3.49 GHz operating frequency.…”