Polarization characteristics in UHF‐band mobile radio propagation

Abstract

AbstractA propagation study has been conducted for horizontal and vertical polarization inside buildings in residential areas and in business districts with tall buildings. The following findings have been obtained: (i) when half‐wave dipole antennas are used both for transmission and reception, the received power is stronger for transmission and reception in the vertical polarization than for transmission and reception in the horizontal polarization. This phenomenon is due to the difference of the directivity of the dipole antenna; (ii) the cross polarization discrimination (XPD), defined as the ratio of the in‐phase polarization component voltage to that of the orthogonal polarization, correlates with the loss increase from the free space propagation. As the latter is increased, the XPD degrades more; (iii) the XPD degrades more as the propagation distance increases. This is because the attenuation constant of the in‐phase polarization component is larger than that of the orthogonal polarization component; (iv) the XPD of the wave propagation outside is determined by the ratio of the RG wave guided along a road to the BD wave diffracted by the top edge of a building. It degrades more as the BD wave component is increased; and (v) for a distance of less than about 1 km line‐of‐sight, the difference in attenuation by the polarization is negligible.