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[pt] Esta dissertação descreve a extensão de uma ferramenta educacional (LESM – Linear Elements Structure Model), desenvolvida na PUC-Rio e implementada no ambiente do MATLAB, para dimensionamento de pórticos metálicos bidimensionais seguindo os preceitos da norma brasileira NBR8800:2008. Todas as etapas de desenvolvimento são descritas detalhadamente, trazendo também referências à norma utilizada, visto que a funcionalidade deve atender rigorosamente a seus preceitos. As etapas adotadas são: levantamento de requisitos da funcionalidade, levantamento de requisitos do software, análise, projeto do programa, codificação, teste e operação. Vale ressaltar que todos os desdobramentos das etapas são baseados na linguagem orientada a objetos MATLAB, na qual o software LESM foi desenvolvido. As etapas de desenvolvimento são elucidadas através de esquemas UML (Linguagem de Modelagem Unificada) para que haja maior entendimento dos relacionamentos organizacionais e processuais utilizados. Dessa maneira podem ser traçados comparativos das novas estruturas de dados implementadas com as anteriormente disponíveis na documentação do LESM. Além disso, apesar da linguagem predominante utilizada no desenvolvimento ser a linguagem do MATLAB, há menções relacionais à JavaScript, utilizado para elaborar alguns recursos da nova funcionalidade. Por fim, após esclarecer todas as nuances do processo de desenvolvimento, são modelados exemplos práticos utilizando o LESM com o intuito de demonstrar a nova funcionalidade adicionada e a acurácia de seus resultados. / [en] This document describes the extension of an educational tool (LESM – Linear Elements Structure Model), developed on PUC-Rio and implemented in the MATLAB environment for metallic dimensioning of 2D frames, following the precepts of the Brazilian dimensioning standard, NBR8800:2008. The entire development steps are described in details, along with references of the standard used, since the new feature must strictly attend its precepts. The order of the adopted steps is: feature requirements gathering, software requirements gathering, analysis, program project, coding, test and operation. It is worth mentioning that all of the steps are based on the objects oriented language MATLAB, which the software LESM was developed. The previously mentioned phases are elucidated through UMLs schemes for a better understanding of the organizational relationships and processes used. Thus, comparatives of the implemented new data structure with the previously available in LESM documentation, disposed in UML diagrams, can be traced. Furthermore, despite the predominant language used in the development is MATLAB, will be also mentions to JavaScript, used to elaborate some resources of the new feature. Finally, after clarifying all aspects of the development process, practical examples using LESM are modeled to demonstrate the new feature along with the results accuracy.

No / To mitigate potential interferences with coexisting wireless systems operating over 3.3-3.6 GHz, 5.15-5.35 GHz, or 5.725-5.825 GHz bands, four novel band-notched antennas suitable for ultra-wideband (UWB) applications are proposed. These include UWB antennas with a single wide notched band, a single narrow notched band, dual notched bands, and triple notched bands. Each antenna comprises a half-circle shaped patch with an open rectangular slot and a half-circle shaped ground plane. Good band-notched performance is achieved by using high permittivity and low dielectric loss substrate, and inserting quarter-wavelength horizontal/vertical stubs or alternatively embedding quarter-wavelength open-ended slots within the feed line. The results of both simulation and measurement confirm that the gain suppression of the single and multiple band-notched antennas in each desired notched band are over 15 dB and 10 dB, respectively. The radiation pattern of the proposed triple band-notched design is relatively stable across the operating frequency band.

This work proposes wideband and broadband Planar Ultra-wideband Modular Antenna (PUMA) arrays designed to improve cost and reliability for high production volume commercial and military applications. The designs feature simplified PCB stack-ups with high dielectric constant (Dk) dimensionally stable materials to improve the manufacturing cost and yield. Additionally, the packages use ball grid array (BGA) interconnects, commonly used in digital electronics, for simple solder reflow integration with radio frequency (RF) electronics. While high Dk materials present practical manufacturing benefits, theoretical background will show how and why PUMA arrays lose frequency bandwidth and scan volume with high Dk materials. Further, a band limiting cavity mode will be shown to encroach into the frequency band of high Dk PUMA arrays due to a higher order common mode. PUMA arrays designed on several high Dk materials (Dk = {2.55, 3, 3.7}) will be presented to characterize this reduction in bandwidth. A wideband 7.25-31 GHz (4.3:1) PUMA array-on-package designed on Rogers RO4725JXR (Dk = 2.55) is presented with infinite array simulation results showing good active impedance match, port isolation and cross-polarization performance out to q = 45°. A simplified broadband 15-21 GHz (30%) PUMA array on a thin (λ/11) single layer of Isola FR408HR (Dk = 3.7) is proposed with infinite array results predicting strong active impedance, port isolation and cross-polarization performance with better port isolation and cross-polarization levels than a similar dual-polarized probe fed patch array.