Rafael F. S. Caldeirinha

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– Modelling radio wave propagation through vegetation is becoming increasingly more important. Many emperical solutions have been suggested in the past. The theory of radiative energy transfer offers an analytical method to the problem. This theory requires however 4 imput paramters, which need to be established experimentally. A measurement of the angular(More)
This paper presents a swept time delayed cross-correlation (STDCC) channel sounder. The proposed topology employs the real-time sliding correlation technique of pseudo-random (PN) sequences, enabling amplitude and Doppler spectrum measurements and analysis of individual multipath components. It makes use of recent technologies, specifically in the(More)
– An analytical model based on the theory of the Radiative Energy Transfer (RET) is used to predict the bistatic scattering pattern of single trees. A set of propagation measurements were designed and carried out at micro-and millimeter wave frequencies to characterise the re-radiation functions of single trees modelled by simpler scattering functions,(More)
—The presence of vegetation in the radio channel could affect the coverage areas of cellular mobile phone systems. The different components of a tree have influence in the performance of the radio system. Whereas the trunk is commonly in a fixed and stable location, the leaves could be in continuous movement forced by the wind. This time variation, which(More)
An important part of the modelling process applied to vegetation effects is aimed at analysing the radio propagation modes and the identification of individual signal contributions to the scattered signal caused by various elements of the tree. The paper describes detailed studies aimed at the wideband characterisation of propagation mechanisms arising in(More)