Banca de QUALIFICAÇÃO: RAFAEL ALEX VIEIRA DO VALE

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : RAFAEL ALEX VIEIRA DO VALE
DATE: 10/12/2024
TIME: 14:00
LOCAL: https://meet.google.com/okv-mtxe-gqf
TITLE:

Manufacturing of Dielectric Resonator Antennas Using Ceramic Waste from Civil Construction

KEY WORDS:

Dielectric Resonator Antennas; Ceramic Waste; Bricks and Tiles; Sierpinski Fractal; Sub-6GHz

PAGES: 198
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
SPECIALTY: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
SUMMARY:

This work presents the fabrication of cylindrical dielectric resonator antennas (DRAs) using ceramic waste from bricks and tiles sourced from a renovation at the Federal University of Ceara (UFC), Russas campus. The cylindrical samples were produced by grinding the ceramic waste, molding them under a uniaxial load of 100 kN in a universal testing machine, and sintering them in a resistive furnace at temperatures of 1000 °C, 1050 °C, and 1100 °C. The resulting specimens were analyzed for their microstructural properties using X-ray diffractometry (XRD) to identify the Bravais lattices and chemical composition of the ceramics. Additionally, energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) were employed to examine the degree of grain coalescence. The physical characteristics of the ceramic cylinders were assessed through porosity measurements. To validate the application of these samples in dielectric resonator antennas, their dielectric behavior was studied by measuring the real relative permittivity and loss tangent as a function of frequency using a vector network analyzer (VNA). The acquired data facilitated the development of models for the DRAs. The designs of the DRAs utilized the aperture-coupled feeding method. They incorporated Sierpinski fractals, featuring a square Sierpinski carpet configuration with two iterations—complementary on the ground plane and non-complementary on the feedline surface. Simulations were conducted to evaluate return losses, gain, radiation efficiency, front-to-back ratio, and 2D patterns in both co-polarization and cross-polarization for the antennas, using two different substrate materials: FR-4 and Rogers RO-3010. The proposed antennas target applications in fifth-generation systems within the Sub-6 GHz band, leveraging ceramic waste as alternative materials and promoting a more sustainable approach to the manufacturing of such devices.

COMMITTEE MEMBERS:
Presidente - 2524053 - ANTONIO LUIZ PEREIRA DE SIQUEIRA CAMPOS
Interno - 1422265 - JOSE PATROCINIO DA SILVA
Externo ao Programa - 1840342 - MARCIO EDUARDO DA COSTA RODRIGUES - UFRN