@PhDThesis{Yamasaki:2017:SiExCh,
author = "Yamasaki, Fernanda Sayuri",
title = "Simulation and experimental characterization of gyromagnetic
nonlinear transmission lines for prospective aerospace
applications",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2017-02-16",
keywords = "gyromagnetic lines, ferrite, NLTL, RF generation, space
applications, linhas giromagn{\'e}ticas, ferrita, LTNL,
gera{\c{c}}{\~a}o de RF, aplica{\c{c}}{\~o}es espaciais.",
abstract = "A great interest has been devoted to the study of nonlinear
transmission lines (NLTLs) for radiofrequency (RF) generation
since they have been used with great success in RF generation by
producing a train of oscillatory waves along the line and at its
output. There are two configurations of NLTLs. The first one is a
dispersive line consisting of LC sections with nonlinear
components, and the second one is a continuous ferrite loaded
non-dispersive line generally biased by an axial magnetic field,
known as gyromagnetic line. In this thesis, the focus of the study
is on the second one, since gyromagnetic lines can operate in a
broader frequency range (0.4 up to 2.0 GHz) with higher conversion
efficiency (20.0 %) when compared to lumped NLTLs limited up to
300.0 MHz with less than 10.0 % of efficiency, because of their
dielectric losses and stray impedances on line structure.
Different models have been used along the years by several authors
with different approaches to study the gyromagnetic phenomenon by
means of numerical simulations based on analytical models to
predict the precession movement of the electron magnetic dipole of
the ferrimagnetic material. Thus, the goal of this thesis is to
analyze the gyromagnetic NLTL behavior through the effects on the
line operation by changing its parameters. The novelty herein is
to use Spice simulations based on LC lumped line models to study
continuous gyromagnetic NLTLs in addition to numerical simulations
usually employed, focusing on the pulse rise time compression and
RF generation caused by magnetic dipole precession. Different
models are studied by comparing Spice simulations with
corresponding results from numerical simulations and experiments
found in the literature. Finally, an experimental set-up is
described for a 20-cm gyromagnetic line loaded with NiZn ferrite
beads to validate with data the proposed method based on Spice
simulations. Finally, it is expected that such Spice techniques
can be used in the design of these continuous lines for RF
applications in space and mobile defense platforms of compact
size. RESUMO: Um grande interesse tem sido dedicado ao estudo de
Linhas de Transmiss{\~a}o N{\~a}o Lineares (LTNLs) para
gera{\c{c}}{\~a}o de radiofrequ{\^e}ncia (RF), uma vez que
t{\^e}m sido utilizadas com grande sucesso na gera{\c{c}}{\~a}o
de RF produzindo um trem de ondas oscilat{\'o}rias ao longo da
linha e em sua sa{\'{\i}}da. Existem duas
configura{\c{c}}{\~o}es de LTNLs, a primeira {\'e} uma linha
dispersiva constitu{\'{\i}}da por se{\c{c}}{\~o}es LC com
componentes n{\~a}o lineares, e a segunda {\'e} uma linha
n{\~a}o dispersiva e cont{\'{\i}}nua, utilizando ferritas
geralmente polarizadas por um campo magn{\'e}tico axial,
conhecida como giromagn{\'e}tica. Nesta tese, o foco do estudo
{\'e} na segunda linha, uma vez que ela pode operar em uma faixa
de frequ{\^e}ncia mais ampla (0,4 a 2,0 GHz) com maior
efici{\^e}ncia de convers{\~a}o (20,0 %) quando comparada a
LTNLs discreta que {\'e} limitada a 300,0 MHz com menos de 10,0 %
de efici{\^e}ncia, por causa de suas perdas diel{\'e}tricas e
imped{\^a}ncias parasitas na estrutura da linha. Diferentes
modelos t{\^e}m sido utilizados ao longo dos anos por v{\'a}rios
autores com diferentes abordagens para estudar o fen{\^o}meno
giromagn{\'e}tico por meio de simula{\c{c}}{\~o}es
num{\'e}ricas baseadas em modelos anal{\'{\i}}ticos para prever
o movimento de precess{\~a}o. Assim, o objetivo desta tese {\'e}
analisar o comportamento de LTNLs giromagn{\'e}ticas atrav{\'e}s
dos efeitos na opera{\c{c}}{\~a}o da linha mudando seus
par{\^a}metros. A novidade aqui {\'e} usar
simula{\c{c}}{\~o}es Spice com base em modelos de linha LC para
estudar as linhas giromagn{\'e}ticas cont{\'{\i}}nuas,
al{\'e}m de simula{\c{c}}{\~o}es num{\'e}ricas normalmente
empregadas, com foco na compress{\~a}o do tempo de subida de
pulso e gera{\c{c}}{\~a}o de RF causada pela precess{\~a}o do
campo magn{\'e}tico. Diferentes modelos s{\~a}o estudados
comparando-se simula{\c{c}}{\~o}es Spice com resultados
correspondentes de simula{\c{c}}{\~o}es num{\'e}ricas e com
experimentos encontrados na literatura. Finalmente, um arranjo
experimental para uma linha giromagn{\'e}tica de 20,0 cm usando
contas de ferrita NiZn foi implementado para validar com dados
experimentais o m{\'e}todo proposto baseado em
simula{\c{c}}{\~o}es Spice. Finalmente, espera-se que tais
t{\'e}cnicas de simula{\c{c}}{\~a}o Spice possam ser usadas na
concep{\c{c}}{\~a}o destas linhas cont{\'{\i}}nuas para
aplica{\c{c}}{\~o}es de RF no espa{\c{c}}o e em plataformas
m{\'o}veis de defesa de tamanho compacto.",
committee = "Santos, Walter Abrah{\~a}o dos (presidente) and Rossi, Jos{\'e}
Osvaldo (orientador) and Castro, Joaquim Jos{\'e} Barroso de
(orientador) and Schamiloglu, Edl (orientador) and Rangel, Elizete
Gon{\c{c}}alves Lopes and Motta, Cl{\'a}udio Costa and Angelis,
Andr{\'e} Franceschi de",
copyholder = "SID/SCD",
englishtitle = "Simula{\c{c}}{\~a}o e caracteriza{\c{c}}{\~a}o experimental de
linhas de transmiss{\~a}o n{\~a}o lineares giromagn{\'e}ticas
para prospectiva aplica{\c{c}}{\~a}o aeroespacial",
language = "en",
pages = "196",
ibi = "8JMKD3MGP3W34P/3N92GBH",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3N92GBH",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}