On the safety evaluation of the space in the vicinity of an aperture antenna

In this paper, the safety evaluation of the space in the vicinity of an aperture antenna is presented. The basis of our consideration is the approximate similarity of the contours between uniformly and nonuniformly illuminated apertures. Using the equivalence of either the gain or the beam width, it was possible to derive the uniform aperture with similar contours to the corresponding nonuniform one. In order to avoid radiofrequency (RF) hazards, instead of the isoparametric contours, their envelopes have been studied. Also, in the case where the exact axial field and the radiation pattern of the aperture are known, the contours can be approximately presented. Several examples with different apertures show the procedure of drawing the contours and explain the validity of our method.