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Traditionally, Frequency Selective Surfaces (FSS) are designed to produce a certain spectral response, in one or more frequency bands, using a methodology that manually tunes and simulates the behavior of the structure. In some cases, due to the high filtering requirements of an application, it could be necessary make FSS with several periodic surfaces, in order to improve the frequency response of...
In the last years, the migration from analog to digital terrestrial television systems has favored the deployment of Single Frequency Networks (SFN), more efficient from a spectrum point of view, to provide DVB-T services in larger geographical areas through the reuse of frequencies. However, the planning of a SFN is not a trivial task, since the designer must find a trade-off between the quality...
In this paper, multiple concentric rings are considered as phase elements in reflectarrays and the benefits of these single layer rings are compared to conventional reflective structures (multi and single layer, rectangular or elliptical printed patches) when applied to the design of reflectarrays. These ring-shaped structures have got, as the main advantages, the ease of manufacture and the wide...
This paper presents and compares different configurations of several heuristic optimization methods with the aim of seeking the one with the best performance when applied to phase synthesis of reflectarray antennas. This phase synthesis is a hard task and improving the synthesis method can result in significant reductions in the associated computational cost. The performance of algorithms such as...
Terrestrial digital broadcasting networks for digital video broadcasting (DVB) systems, such as DVB-T or DVB-T2, can be either multi-frequency (MFN) or single frequency (SFN). Regarding the SFN, the use of the spectrum is more efficient, and receiving locations can be served by several transmitters working at the same frequency. Moreover, DVB receivers based on OFDM modulation schemes can succeed...
Population-based optimization algorithms are widely used in multiple research areas to optimize different kinds of problems. Commonly, they have been successfully applied to low and medium size search spaces in order to tune or adjust several design parameters. Unfortunately, population-based algorithms can require too much CPU time to find a nearly optimal solution as the number of dimensions of...
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