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@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/rep/8JMKD3MGP3W34P/3N92GBH",
           targetfile = "publicacao.pdf",
        urlaccessdate = "05 dez. 2020"
}


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