Made available in DSpace on 2014-12-17T14:54:56Z (GMT). No. of bitstreams: 1 Tese_Cristhianne.pdf: 1342088 bytes, checksum: 1c3372509a24d25d30a4e89f11cd641e (MD5) Previous issue date: 2010-04-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In general, the materials used as substrates in the project of microstrip antennas are: isotropic, anisotropic dielectrics and ferrimagnetic materials (magnetic anisotropy). The use of ferrimagnetic materials as substrates in microstrip patch antennas has been concentrated on the analysis of antennas with circular and rectangular patches. However, a new class of materials, called metamaterials, has been currently the focus of a great deal of interest. These materials exhibit bianisotropic characteristics, with permittivity and permeability tensors. The main objective of this work is to develop a theoretical and numerical analysis for the radiation characteristics of annular ring microstrip antennas, using ferrites and metamaterials as substrates. The full wave analysis is performed in the Hankel transform domain through the application of the Hertz vector potentials. Considering the definition of the Hertz potentials and imposing the boundary conditions, the dyadic Green s function components are obtained relating the surface current density components at the plane of the patch to the electric field tangential components. Then, Galerkin s method is used to obtain a system of matrix equations, whose solution gives the antenna resonant frequency. From this modeling, it is possible to obtain numerical results for the resonant frequency, radiation pattern, return loss, and antenna bandwidth as a function of the annular ring physical parameters, for different configurations and substrates. The theoretical analysis was developed for annular ring microstrip antennas on a double ferrimagnetic/isotropic dielectric substrate or metamaterial/isotropic dielectric substrate. Also, the analysis for annular ring microstrip antennas on a single ferrimagnetic or metamaterial layer and for suspended antennas can be performed as particular cases / Em geral, os materiais utilizados como substratos no projeto de antenas de microfita s?o: diel?tricos isotr?picos, diel?tricos anisotr?picos e ferrimagn?ticos (anisotr?picos magn?ticos). No entanto, o uso de materiais ferrimagn?ticos em substratos de antenas de microfita do tipo patch tem-se concentrado em an?lises que utilizam geometrias circulares e retangulares. Na ?ltima d?cada, uma nova classe de materiais com caracter?sticas bianisotr?picas, apresentando permissividade e permeabilidade tensoriais, tem surgido e despertado bastante interesse, sendo denominados metamateriais. Portanto, este trabalho apresenta uma an?lise te?rica e num?rica das caracter?sticas ressonantes de uma antena de microfita com patch em anel, utilizando como substratos materiais ferrimagn?ticos e metamateriais. A an?lise utiliza o formalismo de onda completa atrav?s da aplica??o do m?todo dos potenciais vetoriais de Hertz, no dom?nio da transformada de Hankel. A defini??o dos potenciais vetoriais de Hertz e a imposi??o das condi??es de contorno adequadas ? estrutura permitem determinar as fun??es di?dicas de Green, relacionando as componentes da densidade de corrente no patch com as componentes tangenciais do campo el?trico. O m?todo de Galerkin ? ent?o usado para obter a equa??o matricial, cuja solu??o n?o trivial fornece a freq??ncia de resson?ncia da antena. A partir da modelagem, ? poss?vel obter resultados para a freq??ncia de resson?ncia em fun??o de v?rios par?metros da antena de microfita com patch em anel, para diferentes configura??es e substratos, al?m do diagrama de radia??o, perda de retorno e da largura de banda. S?o consideradas estruturas de antenas de microfita com patch em anel sobre m?ltiplas camadas ferrimagn?tica/metamaterial sobre diel?trico isotr?pico. A an?lise num?rica para antenas com uma ?nica camada ferrimagn?tica ou metamaterial e para antenas suspensas s?o obtidas como casos particulares