Banca de DEFESA: MARCELO DAVID SILVA DE MESQUITA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : MARCELO DAVID SILVA DE MESQUITA
DATA : 31/05/2019
HORA: 15:00
LOCAL: Auditório do CTEC
TÍTULO:

SYNTHESIS OF A NEW CONDUCTIVE INK FOR MICROWAVE PRINTED CIRCUITS ON GLASS AND FIBERGLASS SUBSTRATES

PALAVRAS-CHAVES:

Conductive ink, silver ink, nitrocellulose, microstrip antennas, FSS, directional couplers, DC blocks.

PÁGINAS: 103
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
ESPECIALIDADE: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
RESUMO:

This thesis describes the work carried out for the synthesis of a new conductive ink, with high concentration of silver particles, and the investigation on the possibility of its use in the manufacture of integrated circuits for wireless communication systems. The use of the new conductive ink is proposed as an alternative to the use of conventional microwave integrated circuits manufacturing techniques. The great interest in the use of conductive ink is associated with the ease, efficiency, versatility and reduction of manufacturing costs of the integrated circuits, provided by the use of small paint brushes for the application on different dielectric materials. The conductive ink obtained from the synthesis of nitrocellulose, which, in ethyl acetate solution, acts as a bonding agent of the pigment (silver metallic powder) to form a conductive film, one of the contributions of this work. The synthesized conductive ink was used in the development of microstrip antennas, bioinspired frequency selective surfaces (FSS), DC blocks, and directional couplers. The last two microwave integrated circuits were developed using parallel coupled microstrip lines. The simulation and design of these circuits were performed using Ansoft Designer and Ansoft HFSS softwares. In the analyses, glass and fiberglass substrates, very thin conductive plates made out of copper and silver, and surfaces painted with silver ink were considered. The frequency behavior of the scattering parameters of these circuits were investigated, enabling the evaluation of different aspects related to the transmission, reflection, coupling, radiation, and electromagnetic wave filtering. In order to validate the simulation results and to compare the measurement results, prototypes of microstrip antennas were fabricated and measured on fiberglass substrates with a copper laminate and with a surface painted with conductive ink. Also, prototypes of microstrip antennas were manufactured on glass substrate. The measurement of the reflection coefficient and the input impedance of these antennas were performed using a network analyzer. In the case of FSSs, prototypes were simulated and manufactured with elements inspired on the leaf of the Oxalis triangularis plant on fiberglass substrates, with copper clad laminate and surfaces painted with the synthesized conductive ink. The transmission coefficient measurement of these FSSs were performed using a network analyzer and two horn antennas. In the cases of DC block and directional coupler, prototypes were simulated on fiberglass substrates, with copper clad laminate and with surface painted with conductive ink, providing the opportunity to investigate the effect on the electromagnetic coupling between the painted parallel microstrip lines. The measurement of the reflection and transmission coefficients of these circuits were carried out using a network analyzer. The good agreement observed between the simulated and measured results for the microwave integrated circuit prototypes painted with silver ink confirms the efficiency and versatility of the painting procedure with the synthesized conductive ink.

MEMBROS DA BANCA:
Presidente - 6345784 - ADAILDO GOMES D ASSUNCAO
Interno - 349732 - LAERCIO MARTINS DE MENDONCA
Externo ao Programa - 338292 - JOAO BOSCO LUCENA DE OLIVEIRA
Externo à Instituição - ADAILDO GOMES D ASSUNCAO JUNIOR - IFPB
Externo à Instituição - JEFFERSON COSTA E SILVA - IFPB
Externa à Instituição - MARIA THEREZA MIRANDA ROCCO GIRALDI - IME