Banca de DEFESA: YURI MAX VIEIRA BATISTA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : YURI MAX VIEIRA BATISTA
DATA : 13/07/2018
HORA: 09:00
LOCAL: Auditório do DCO, no CTEC
TÍTULO:

ANALYSIS OF FRACTAL INSPIRED STRUCTURES APPLIED TO ANTENNAS AND FREQUENCY SELECTIVE SURFACES

PALAVRAS-CHAVES:

Fractal, modified fractal, fractal antenna, fractal FSS, microstrip antenna, frequency selective surface, FSS

PÁGINAS: 75
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
ESPECIALIDADE: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
RESUMO:

The development of new fractal-based structures applied to planar technology has motivated many researchers around the world, who are very interested in the design of compact, stable, efficient, and low cost microwave devices and circuits for wideband, ultra wideband, and multiband frequency applictions, with enhanced filtering (transmission or rejection) and radiation (or rejection) characteristics, for example.

Specifically, the geometry of traditional fractals have been widely used in the development of integrated circuits for microwaves and antennas because they have enhanced their frequency responses. However, in order to extract more advantages from the potential of these geometries, they must be changed according to the particular applications. In addition, due to external interference, spatial filters, such as frequency selective surfaces (FSS), have become increasingly popular with the large growth in the use of wireless technologies, as they appear to be an excellent solution for predetermined frequency filtering.

In addition, the use of traditional or new fractal geometries in these structures always brings particular contributions in improving their frequency responses. Therefore, the main objective of this work is to improve current FSS technology using known fractal geometries, which are modified, to take more advantage of the use of these geometries’ characteristics.

Thus, using some different configurations of the same architecture, inspired by the Hilbert fractal, one can configure the structure of the FSS to obtain improved bandwidth, multi-band operations, good angular stability, and compactness, for example. In addition, these fractal-based structures exhibit characteristics to be investigated with respect to the size reduction of the patch element of the periodic array and to the modification of the antennas resonance frequencies.

Results using a FSS as ground plane in a rectangular patch antenna structure with inset-feed suggest the possibility of significantly decreasing the antenna resonant frequency, as well as the appearance of multiple resonance bands, as if the patch had a fractal geometry. This work compiles the experiment of several fracture-inspired antennas and FSS structures that resonate in different frequencies. Several prototypes are fabricated and measured to validate the simulation results.

This work presents FSS geometries inspired on the Hilbert fractal, the infinite mirror fractal, and the Sierpinski triangle geometries, with additional modifications to ensure angular and multiband stability. In addition, the developed antennas are inspired on Sierpinski fractal geometries, with Hilbert-inspired ground planes, as well as antennas inspired on the fractal of the image, enabling multiband frequency behavior and miniaturization.

MEMBROS DA BANCA:
Interno - 6345784 - ADAILDO GOMES D ASSUNCAO
Interno - 349732 - LAERCIO MARTINS DE MENDONCA
Externo à Instituição - ADAILDO GOMES D ASSUNCAO JUNIOR - IFPB
Externo à Instituição - ALFREDO GOMES NETO - IFPB