Worst case approximation of antenna near fields

Application of reliable approximations of antenna near fields (NF) is very helpful to increase the efficiency of existing procedures for electromagnetic compatibility (EMC) analysis and human exposure assessment. This paper provides simple analytical formulas for the worst case estimation of power density (PD) of antenna NF in the direction of maximum radiation. The new approximation formulas are based on the equivalence between the real antenna and the uniform rectangular aperture with the same half power beamwidth (BW). The accuracy of approximation is tested by electromagnetic calculations of circular and rectangular aperture antennas and is compared with antenna NF templates recommended by guidelines of Safety Level of Human Exposure standards.