Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-28T19:29:08Z No. of bitstreams: 1 EduardoJorgeBritoRodrigues_TESE.pdf: 43872870 bytes, checksum: 17c0e713bafaa6d4d624d7f72b31cee4 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-29T18:46:26Z (GMT) No. of bitstreams: 1 EduardoJorgeBritoRodrigues_TESE.pdf: 43872870 bytes, checksum: 17c0e713bafaa6d4d624d7f72b31cee4 (MD5) / Made available in DSpace on 2017-03-29T18:46:26Z (GMT). No. of bitstreams: 1 EduardoJorgeBritoRodrigues_TESE.pdf: 43872870 bytes, checksum: 17c0e713bafaa6d4d624d7f72b31cee4 (MD5) Previous issue date: 2016-06-06 / A efici?ncia no uso das radiofrequ?ncias (RF) ? um fator determinante na capacidade de qualquer sistema de comunica??es m?veis. O aprimoramento da utiliza??o desses recursos tornou-se interessante desde os prim?rdios desses sistemas. As tecnologias e servi?os digitais tem demandado maior aloca??o RF para suprir requisitos de largura de banda (BW). O desenvolvimento de tecnologias emergentes baseadas em aloca??o din?mica de RF tem sido apontado como uma solu??o para essa crescente necessidade de BW e motiva??o para a realiza??o de recentes pesquisas sobre os sistemas de r?dios cognitivos (CRS). Neste trabalho, s?o propostas antenas de banda ultra larga (UWB) para sensoriamento espectral, assim como antenas reconfigur?veis em frequ?ncia para aplica??es em CRS, os quais realizam de forma din?mica a transmiss?o e recep??o de sinais em banda estreita (NB). Dentre os prot?tipos propostos, s?o trazidos modelos capazes de cobrir todo o espectro de 3,1 GHz a 10,6 GHz, assim como, de forma reconfigur?vel, cobrir essa faixa de RF em v?rias NB, com destaque para a frequ?ncia de 5,8 GHz. Ademais, as antenas propostas passaram por processos de otimiza??o e s?ntese baseados em ferramentas de intelig?ncia computacional quais sejam: algoritmo gen?tico (GA), o algoritmo de otimiza??o de enxames de part?culas (PSO), assim como o algoritmo de otimiza??o de col?nia de abelhas artificial (ABC). Como resultados, melhorias na BW e no coeficiente de reflex?o das antenas foram encontradas. As simula??es e parametriza??es computacionais, assim como as an?lises num?ricas com GA, foram realizadas com aux?lio do software HFSS. J? as an?lises num?ricas com algoritmos PSO e ABC foram implementadas em Java. Para fins de valida??o, os resultados dessas simula??es foram comparados com resultados experimentais, tendo sido observada boa concord?ncia para os diversos prot?tipos de antenas planares propostos e desenvolvidas neste trabalho. / The effective usage of radio frequencies (RF) is a determining factor in the capacity of any mobile communications system. Improving the use of these resources has become very popular since the early days of these systems. The technologies and digital services have demanded higher RF allocation to meet bandwidth (BW) requirements. The development of emerging technologies based on dynamic RF allocation has been considered as a solution to this growing need for BW and motivation to carry out recent research on cognitive radio systems (CRS). In this work, UWB antennas are proposed for spectral sensing, as well as frequency reconfigurable antennas for CRS applications, which dynamically perform transmitting and receiving signals in narrowband (NB). Among the proposed prototypes, the presented models are able to cover the entire UWB spectrum from 3.1 GHz to 10.6 GHz. When working as reconfigurable antennas, the prototypes can cover the RF range in various NB, like 5.8 GHz. Moreover, the proposed antenna passed through optimization and synthesis processes based on computational intelligence tools. Genetic algorithm (GA), particle swarm optimization (PSO) algorithm, and artificial bee colony (ABC) algorithm are the used algorithms. As results, improved BW and the better antenna reflection coefficient were found. The computational simulations and the numerical analysis based on GA were performed using the HFSS software. In addition, numerical analyses with PSO and ABC algorithms were implemented in Java. For validation purposes, simulation results were compared with experimental results showing good agreement for all the proposed planar antennas prototypes developed in this work.