A Fraunhofer-Based Approach for the Assessment of the Field Radiated in the Fresnel Region of an Antenna

Electromagnetic field representation in the radiating near field region of Bases Transceiver Station antennas

“…Sometimes it is referred as conservative, but it is demonstrated that in the Fresnel region of a radiator it may produce underestimations [4], particularly significant in the 2010 17th International Conference on Telecommunications 978-1-4244-5247-7/09/$26.00 ©2009 IEEE angular region of the major side lobes [7]. For these reasons the method is not suggested for applications in the Fresnel region of the radiator, in favor of a hybrid combination of the Adjusted Spherical and the Cylindrical Models.…”

“…Recently, a Fraunhofer-based approach has been proposed [7] for a simplified and immediate field representation in the Fresnel region of BTS antennas. It does not require the knowledge of geometrical and electrical antenna data in advance, out of the standard ones published on the data sheets.…”

Simplified numerical field assessment in the Fresnel region of BTS antennas

“…The Fraunhofer-based approach [4] introduces a direct analytical evaluation of the field, starting exclusively from the knowledge of the horizontal and vertical cuts of the Fraunhofer radiation pattern, individually modified by means of correction factors that introduce a combined distance/angular analytical dependency. E.g., the power density S radiated in any vertical plane is calculated as: (1) where SFR is the power density in that plane, calculated by means of the standard Fraunhofer radiation patterns, and the L1 functions introduce correction coefficients that guarantee a rather conservative result, avoiding excessive overestimations.…”

“…Recently, a Fraunhofer-based method for exposure assessment in the Fresnel region has been published [4]. The method allows an immediate solution and does not require the knowledge of any geometrical or electrical data, representing an efficient means to address exposure assessment requirements for all those situations involving the presence of accessible spaces below the limit of the Fraunhofer region of the radiator.…”

“…The method allows an immediate solution and does not require the knowledge of any geometrical or electrical data, representing an efficient means to address exposure assessment requirements for all those situations involving the presence of accessible spaces below the limit of the Fraunhofer region of the radiator. The present paper analyses the applicability of the method proposed in [4] to exposure assessment issues, and introduces some preliminary results that demonstrate its reliability and usability for Base Transceiver Station (BTS) antennas.…”