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A measurement campaign has been designed and developed to test the polarization behavior of different obstacles when a 5 GHz radio wave reaches their surfaces from different angles of incidence, with two orthogonal polarizations in transmission. The measurement outcomes have been analyzed by means of a matrix procedure, which is inspired in the polarimetric matrix formulation. This method allows the computation of depolarization indexes. The results highlight a strong depolarization of waves. A set of depolarization indexes for specular direction is given for several angles of incidence and three different materials, with direct application to wireless local area networks planning. These results are interesting for radio systems planning to double the channel capacity, if orthogonally polarized transmissions are used, or to mitigate the signal fading, if diversity techniques are applied at reception. Index Terms--Cross polarization, dielectric materials, electromagnetic scattering measurements, wireless LAN.

Indoor radio channel planning tools implement different models to simulate propagation mechanisms such as transmission or reflection. The specular reflection formulation is commonly used instead of more complete scattering models. This happens because its coding is less complicated and the software runs faster than when considering reflection in all directions, not yet specular. In this paper, results from measurements are presented, consisting of the effect of constructive walls on an oblique incident wave. These experimental outcomes are modelled by means reflection pattern computations. Physical optics scattering model is used in its classical formulation, and it is then modified to take into account antenna pattern effects in the measurements. The comparison between measurements and simulations is also presented, showing good agreement. Measurements show that low reflective walls produce reflections in several directions across the incidence region. In these situations, the use of algorithms that compute reflection pattern, instead of just specular reflection coefficients, will lead to better agreement with actual results. Index Terms--Dielectric surface, reflection, scattering.

The growing interest in the relation between electromagnetic fields and human health forces the assumption of national and international regulations on emission levels. In order to reduce the risks, restricted access around transmitting antennas have to be defined according with those regulations. This paper offers a guideline to determine the boundary of the potentially risky volumes around radio broadcasting antennas for AM-MF and FM-VHF services. With the proposed method, a complete reference volume is defined by just five parameters. Index Terms--Antenna radiation patterns, biological effects of electro-magnetic radiation, electromagnetic radiation effects, Pollution.

In this letter, an improvement of the well-known internal multireflection model of transmission coefficients is proposed in order to obtain better agreement with complex measured data. The reason for the introduced changes is explained. To obtain the data, measurements were performed at 5.8 GHz using a vector network analyzer, which provided information on the amplitude and phase of the transmission coefficient. By comparing the model and measurements, both the real and imaginary parts of the material complex permittivity were estimated for four different building materials. Index Terms--Dielectric materials, electromagnetic scattering, permittivity measurement, urban propagation.