Influence of Base Stations Radiation Patterns on the Level of the Outdoor Electromagnetic Background Created by Mobile (Cellular) Communications

Base stations (BS) radiation is the main source of electromagnetic background generated by mobile (cellular) communications. The known technique for estimating an average intensity of background generated by BS radiation takes into account the directivity of BS antennas in a simplified form, assuming that the width of the main lobe of the radiation pattern is equal to the width of BS servicing sector and not taking into account the radiation directivity in vertical plane. Noted simplifications determine too pessimistic nature of these estimations. The paper contains results of the refined analysis of this problem using a two-level models of antenna radiation patterns, which give the actual values of the width of antennas main lobe in horizontal and vertical planes, the relative levels of side lobes and the ratio of radiation power of the main and side lobes. The analysis was performed both for stationary sector antennas of cellular communication systems and for adaptive phased antenna arrays of 4G/5G systems capable of providing service using narrow beams. Obtained results reduce by 5-15 dB the degree of pessimism provided by known techniques in the estimation of the average levels of electromagnetic background created by BS radiations near the Earth's surface.