Browsing by Author "Sanchez, Manuel Garcia"
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- A 2D ray-tracing based model for wave propagation through forests at micro-and millimeter wave frequenciesPublication . Leonor, Nuno R.; Sanchez, Manuel Garcia; Fernandes, Telmo; Caldeirinha, Rafael F. S.This paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees’ re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.
- A 2D Ray-Tracing Based Model for Wave Propagation Through Forests at Micro-and Millimeter Wave FrequenciesPublication . Leonor, Nuno R.; Sanchez, Manuel Garcia; Fernandes, Telmo, Telmo Rui Carvalhinho Cunha, Telmo R.; Caldeirinha, RafaelThis paper proposes the extension of a 2-D ray-tracing-based model for radiowave propagation in the presence of trees and vegetation areas to include real-sized trees and outdoor forest scenarios. The original propagation model proved to be suitable to characterize the electromagnetic behavior in the presence of indoor tree formation scenarios, despite some limitations found when applied to real-sized trees. In addition, the original propagation model requires the prior knowledge of the trees' re-radiation function to extract the relevant propagation input parameters, which is not always possible to obtain in outdoor scenarios. Therefore, an empirical method to extract the relevant input propagation parameters based on simple measurements is proposed. The performance of the proposed propagation model extension is extensively assessed in both the line-of-trees and tree formation scenarios, including various (and mixed) species, both in- and out-of-leaf foliation states, and at three signal frequencies. Finally, depending on the type of scenario, a benchmark between the proposed propagation model and both the radiative energy transfer (RET) and discrete RET (dRET) models, for line-of-trees and tree formation, respectively, is presented.
- A Three-Dimensional Directive Antenna Pattern Interpolation MethodPublication . Leonor, Nuno R.; Caldeirinha, Rafael; Sanchez, Manuel Garcia; Fernandes, Telmo R.An interpolation method to reconstruct the 3-D directive antenna pattern is presented. The proposed method is based on the prior knowledge of the original antenna's principal planes patterns, to which a specific weighting method is applied to obtain an approximate 3-D antenna pattern. The performance of the proposed interpolation method is evaluated against 3-D antenna patterns from three typical directional antennas, extracted from appropriate electromagnetic simulation. Finally, a comparative analysis between the proposed method and current interpolation methods present in the literature is presented.