Window effect on wall penetration loss in mobile communications
In mobile communication scenarios, a window opening on a wall enhances the field strength inside the room, as compared to a whole wall. Scarce models in the literature address this topic, or objectively quantify this effect relating it to window dimensions - this is the objective of the present paper. Wall and window are treated as an antenna aperture with the appropriate field distribution, which re-radiates its near field into the room. Measurements on a scaled model of a wall with different window sizes show good agreement with simulations. Based on simulation results, a statistical model is constructed to enable fast quantification of the window effect through a "window gain" parameter.
Comparisons of UTD-Based and FK Models for Propagation Through Windows
Radio propagation through building windows is an important mechanism since windows can act as a low-loss propagation path, channeling radio signals into buildings. This letter presents a brief review and analysis of existing deterministic methods for radio propagation through windows. The performance of each different model is briefly described and comparatively analyzed, focusing on the geometry/uniform theory of diffraction (GTD/UTD) method and Fresnel-Kirchhoff (FK) diffraction model. Advantages and disadvantages of each method in terms of efficiency and accuracy are discussed.
Influence of electric fields on friction electrification between metals and borosilicate glass
Abstract In a cylindrical geometry, electric fields were applied through the entire contact area between the sliding metal and the glass surface. The maximum electric charges developed on the metal were measured and plotted against the applied voltage producing the field. The metals were high-purity nickel and gold. The borosilicate glass was Pyrex, brand 7740. The experiments with nickel, which has a work function greater than that of the glass, were performed in 10 −7 mm Hg vacuum. The experiments with gold, with a work function smaller than that of glass, were carried out in air at atmospheric pressure. The results show that: 1. 1) There is both asymmetry and a reversed slope portion in the charge vs. voltage plot. 2. 2) For a certain range of reversing fields, the electric charge developed on the nickel is always negative and the charge on gold is always positive.