@MastersThesis{Oliveira:2021:CoFeRe,
author = "Oliveira, Ana Paula Silva de",
title = "Comp{\'o}sitos de ferrocarbonila em resina ep{\'o}xi como
material absorvedor de radia{\c{c}}{\~a}o eletromagn{\'e}tica
na banda-Ku",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2021",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2021-05-21",
keywords = "ferrocarbonila, materiais absorvedores, m{\'e}todo de
transmiss{\~a}o e reflex{\~a}o (NRW), parametro-S,
simula{\c{c}}{\~a}o, carbonyl iron, eletromagnetic radiation
absorbing materials, transmission and reflection method (NRW),
parameter-S, simulation.",
abstract = "A popularidade de dispositivos eletr{\^o}nicos m{\'o}veis tais
como tablets, computadores, smartphones, entre outros, somados aos
dispositivos fixos como torres de alta tens{\~a}o e redes de
transmiss{\~a}o de energia, antenas de radiodifus{\~a}o e de
telecomunica{\c{c}}{\~a}o, tem causado um aumento na
emiss{\~a}o e propaga{\c{c}}{\~a}o de radia{\c{c}}{\~a}o
eletromagn{\'e}tica e assim tem se tornado uma fonte de
polui{\c{c}}{\~a}o eletromagn{\'e}tica (PEM). A PEM {\'e}
indesej{\'a}vel, incontrol{\'a}vel e tem se tornado um problema
cada vez mais s{\'e}rio nos dias atuais, pois, al{\'e}m da
exposi{\c{c}}{\~a}o invis{\'{\i}}vel aos humanos, e estar
sempre presente, pode causar danos biol{\'o}gicos. Al{\'e}m
disto, a PEM pode interferir no correto funcionamento de
dispositivos eletr{\^o}nicos. Neste sentido, materiais
absorvedores de radia{\c{c}}{\~a}o eletromagn{\'e}tica (MARE)
apresentam caracter{\'{\i}}sticas {\'u}nicas no sentido de
promover a troca de energia da radia{\c{c}}{\~a}o
eletromagn{\'e}tica pela energia t{\'e}rmica. O uso destes
materiais se faz necess{\'a}rio em diversos dispositivos como, de
telecomunica{\c{c}}{\~o}es, processamento digital de
informa{\c{c}}{\~o}es, redes de distribui{\c{c}}{\~a}o e
energia, telefonia celular, equipamentos hospitalares entre
outros. No entanto, esses materiais apresentam como principais
desvantagens, o peso e o volume ocupado pelo material final.
Devido ao grande potencial de aplica{\c{c}}{\~a}o, este trabalho
prop{\~o}e a prepara{\c{c}}{\~a}o de amostras MARE em uma
matriz de ep{\'o}xi, usando como aditivo a ferrocarbonila (FC).
Foram produzidas amostras nas concentra{\c{c}}{\~o}es de 60%,
70% e 80% de FC nas espessuras de 1 mm, 2 mm e 3 mm. A melhor
atenua{\c{c}}{\~a}o ocorreu para a amostra de 2 mm com 70% de
FC, e apresentou uma atenua{\c{c}}{\~a}o de -22,0 dB em 12,4
GHz. As amostras com 60% e 70% tamb{\'e}m apresentaram
atenua{\c{c}}{\~a}o abaixo de -10 dB, o que equivale a 90%
atenua{\c{c}}{\~a}o. Os resultados experimentais foram
corroborados por um modelo te{\'o}rico. Um estudo te{\'o}rico,
em diferentes espessuras, evidenciou que para a
concentra{\c{c}}{\~a}o de 70% a espessura de 1,5 mm apresentaria
uma atenua{\c{c}}{\~a}o de aproximadamente 36 dB. Esta amostra
foi produzida e os resultados experimentais revelaram uma
atenua{\c{c}}{\~a}o em 16,7 GHz com -36,7 dB. Estes resultados
mostram que para a FC, h{\'a} uma concord{\^a}ncia entre os
resultados experimentais e te{\'o}ricos. Entre os mecanismos de
atenua{\c{c}}{\~a}o estudados verificou-se que tanto a corrente
parasita (Eddy Current) quanto o cancelamento de 1 4 de onda podem
ser os mecanismos com maior influ{\^e}ncia no processo de
atenua{\c{c}}{\~a}o. ABSTRACT: The popularity of mobile
electronic devices such as tablets, computers, smartphones, among
others, added to fixed devices such as high voltage towers and
power transmission networks, broadcasting and telecommunication
antennas, has caused an increase in the emission and propagation
of radiation electromagnetic pollution and thus has become a
source of electromagnetic pollution (PEM). PEM is undesirable,
uncontrollable, and it becomes a serious problem these days.
Besides, PEM is invisible, it is always present and can cause
biological damage to human beings. Furthermore, PEM can interfere
with the correct functioning of electronic devices. In this sense,
electromagnetic radiation absorbing materials (MARE) have unique
characteristics in the sense of promoting the exchange of energy
from electromagnetic radiation to thermal energy. The use of these
materials is necessary for various devices such as
telecommunications, digital information processing, distribution
and energy networks, cell telephony, hospital equipment, among
others. However, these materials have, as main disadvantages, the
weight, and volume occupied by the final material. Due to the
great application potential, this work proposes the preparation of
MARE samples in an epoxy matrix, using ferrocarbonyl (FC) as an
additive. Samples were produced at concentrations of 60%, 70%, and
80% FC in thicknesses of 1 mm, 2 mm, and 3 mm. The best
attenuation occurred for the 2 mm sample with 70% FC, and had an
attenuation of -22.0 dB at 12.4 GHz. The samples with 60 and 70%
also had attenuation below -10 dB, equivalent to 90% attenuation.
The experimental results were supported by a theoretical model. A
theoretical study, in different thicknesses, showed that for a
concentration of 70% the thickness of 1.5 mm would present an
attenuation of approximately 36 dB. This sample was produced and
experimental results revealed an attenuation at 16.7 GHz with
-36.7 dB. These results show that for FC, there is an agreement
between experimental and theoretical results. Among the studied
attenuation mechanisms, it was found that both the Eddy Current
and the 1 4 wave cancellation maybe the mechanisms with the
greatest influence on the attenuation process.",
committee = "Baldan, Maur{\'{\i}}cio Ribeiro (orientador/presidente) and
Mineiro, Sergio Luiz (orientador) and Okamoto, Sayuri and
Matsushima, Jorge Tadao",
englishtitle = "Carbonyl iron composites in epoxy resin as an absorber material
for electromagnetic radiation in the Ku Band",
language = "pt",
pages = "105",
ibi = "8JMKD3MGP3W34T/452M3DL",
url = "http://urlib.net/ibi/8JMKD3MGP3W34T/452M3DL",
targetfile = "publicacao.pdf",
urlaccessdate = "2024, Apr. 29"
}