The frequent advancement of telecommunications related technologies means that more regulatory organisations raise their concern about the possible effects that EM radiation can cause on people. Therefore, several parameters are established with the objective of evaluating if a region is within tolerance limits of radiation. Thus, it is necessary to know these evaluation parameters and how these fields are distributed throughout a region. The aim is to evaluate which method of interpolation, among the studied techniques, has the best performance to estimate accurately the intensity values of electric fields by analysing the parameters mean absolute error and RMS error. The exposure ratio was also verified aiming to check if it was within the limits established by international standards, in the range from 10 MHz to 8 GHz in the central region of the city of Mossoró, Brazil.

No abstract

This work aims to analyze the factors that influence the radiation properties of dualband microstrip antenna using periodic structures based on Photonic Band Gap with hexagonal symmetry. An increase in bandwidth and a reduction of return loss for the second operating band of the antenna were observed.

This article presents an investigation about the parameters of rectangular microstrip patch antennas with resonators on the antenna's substrate, through a experimental collection, it has been observed a simulation analysis and its verification by measured data. This investigation refers to two arrayed sets on the substrate, the first one with 16 resonators and the second one with 36. The substrate composition of the antenna have been based on the use of split ring resonators, periodically organized on arrays and confined on the substrate. By applying this proposal, it has been made an evaluation of return loss behavior related to the operation frequency, bandwidth, gain, and feature impedance, in which intended to compare the obtained values to each spacial disposition of the resonator elements. The result analysis demonstrated acceptable agreement between simulated and measured values.

This study analyses the influence of a metasurface coupled to a rectangular microstrip antenna. The proposed metasurface converts linearly polarised electromagnetic waves into circularly polarised electromagnetic waves. The rectangular microstrip antenna is designed to operate at 2.45 GHz. The metasurface is coupled to the antenna in order to provide a structure capable of radiating circularly polarised electromagnetic waves without the need for adjustments to the antenna feed. In this analysis, the metasurface was designed from unit cells, distributed in a periodic arrangement acting as a polariser, when coupled to the upper part of the antenna. The geometry of the unit cells and their distribution in the arrangement were calculated in order to obtain an axial ratio below 3 dB in the design frequency range. Prototypes of the microstrip antenna and the metasurface were constructed to obtain experimental results and it was possible to observe a good convergence between the simulated and measured results.