D'ASSUNÇÃO JÚNIOR, A. G.; http://lattes.cnpq.br/7359899329008024; D'ASSUNÇÃO JÚNIOR, Adaildo Gomes .
Resumo:
The great development of the telecommunications observed in these days is
mainly due to recent technological achievements and to the seeking for new facilities to
make fast, efficient, and diverse communication connections among users, when and
where needed. In order to get that it is necessary to develop even smaller, lighter and
easy to build, as well as integrate, high frequency devices and circuits for communication
systems. Thereafter it is necessary the development of high frequency devices and
circuits to be used in both multiband and wideband (UWB) applications. Besides these
requirements can be accomplished using microwave and millimeter wave integrated
circuits due to their intrinsic properties. Therefore the analysis and proposition of new
integrated circuits, like planar antennas and frequency selective surfaces (FSS) is needed
and are being investigated by many researchers all over the world. This work proposes
and describes the use of the Wave Concept Iterative Procedure (WCIP), an accurate and
efficient full-wave analysis method, to investigate the properties of planar antennas and
FSS for applications at microwave and terahertz (THz) bands. Particularly WCIP is used in
this work to develop: a) new geometries for planar antennas and wideband isolated FSS,
b) side by side, as well as broadside, coupled FSS, c) dual polarized FSS, d) FSS with
reconfigurable geometries, and e) in a break through (step forward), optical
communications geometries. The derived equations using WCIP are implemented in
Matlab codes to investigate microstrip antennas and isolated and coupled FSS properties.
The antenna geometries analyses are focused in the determination of resonant
frequencies, bandwidths, and return loss parameters. In the case for FSS the focus is the
determination of resonant frequencies, bandwidths, and insertion loss parameters. In
both cases the WCIP accuracy and efficiency are addressed. Furthermore several
antennas and FSS prototypes are built and measured for comparison purposes, and
agreement is observed between simulated and measured results. Afterward the
properties of several THz band integrated circuits are investigated through WCIP. Among
them those such as: a) slot dipoles, b) collinear array of two slot dipoles, and coupled
metallic ring sectors, to verify the WCIP potentiality and adaptability in analyzing THz
antenna and FSS structures. WCIP simulated results are compared to those obtained
through Ansoft Designer showing a good agreement.