Made available in DSpace on 2014-12-17T14:55:33Z (GMT). No. of bitstreams: 1 FlaviaCC_Capa_ate_pag15.pdf: 8751469 bytes, checksum: df79b8a134d4a6869e65f7ed508775af (MD5) Previous issue date: 2009-11-17 / ln this work, planar quasi- Y agi antennas are investigated based on the concept of the classic Y agi_Uda antennas. These antennas represent improvements on the topologies of the antennas existing printed because they present characteristics of broad bandwidth, excellent radiation diagrams and simple construction. New configurations are adapted for the driver of the antennas, introducing patches elements into the driver. These new configurations are named Patches Elements Anteonas (PEA). This adaptation is obtained from simulations that are executed usiog the software C8T Microwave 8tudio 5. After doing the optimizations, procedures for construction and measurement ofthe prototypes are executed in order to improve the performance of the antennas in such way that they could be used in wireless communication applications, such as Bluetooth, WLAN' s and Wi-Fi. Next, the quasi- Y agi antennas are studied in order to implement them in arrangements. The arrangements construction is based 00 the best driver configuration of the antenna developed in this work. First, a linear arrangement composed by two elements of quasi?Yagi antennas is constructed in such way that the radiation characteristics and the mutual coupling effects could be analyzed. After that, a 90? angle arrangement composed by two elements is studied to observe the effect of circular polarization. Experiments are executed in order to evaluate the arrangements performance. The experimental results show that the analysis made in this work is efficient and accurate. The numerical values obtained for the analyzed parameters of each structure developed are compared with the experimental values. 80, it is possible to observe a good concordance between them. Finally, some future works proposals are presented / Neste trabalho, antenas planares quasi-Yagi s?o estudadas com base no conceito das antenas Yagi-Uda cl?ssicas. Estas antenas representam melhorias sobre as topologias das antenas impressas existentes por apresentarem caracter?sticas de banda larga, excelentes diagramas de irradia??o e constru??o simples. Novas configura??es s?o adaptadas para o driver das antenas, introduzindo elementos patches sobre o driver. Essas novas configura??es s?o chamadas de Antenas de Elementos Patches (AEP). Esta adapta??o ? obtida realizando simula??es de otimiza??o com o aux?lio do software CST Microwave Studio 5. Ap?s as otimiza??es, procedimentos para constru??o e medi??o dos prot?tipos s?o realizados com o objetivo de melhorar o desempenho das antenas para aplica??es de comunica??es sem fio, tais como Bluetooth, WLAN's e Wi-Fi. Posteriormente, as antenas quasi- Yagi s?o estudadas com o intuito de implement?-Ias em arranjos. A constru??o dos arranjos baseia-se na melhor configura??o do driver da antena desenvolvida por este trabalho. Primeiramente, um arranjo linear com dois elementos de antenas quasi-Yagi ? constru?do de tal forma que as caracter?sticas de irradia??o e o efeito do acoplamento m?tuo pudessem ser analisados. Em seguida, um arranjo composto por dois elementos dispostos sob um ?ngulo de 900 ? estudado para se observar o efeito da polariza??o circular. Experimentos s?o executados para avaliar o desempenho dos arranjos. Os resultados dos experimentos demonstram que a an?lise efetuada neste trabalho ? eficiente e precisa. Os valores num?ricos obtidos para os par?metros analisados em cada estrutura desenvolvida s?o comparados com os valores experimentais. Com isso, ? poss?vel observar uma boa concord?ncia entre eles. Por fim, algumas propostas para a realiza??o de trabalhos futuros s?o apresentadas