Appendix: A Technique for Determining Safe Separation Distances for Personnel and Electronic Equipment in the Near-Field of Short Dipole Antennas A Graphical Method - Its Development and Use: Appendix: Mathematical Development of Near-Field Distance Nomograms

The equivalent plane-wave power density in the near-field can be expressed in terms of the power density as determined by the far-field equation and the relative slopes of the NF curves and the FF curve from their respective points of intersection. For the NF1 and the FF curve, that intersection is chosen to occur at one (1) wavelength — the basic reference point for these analyses. Accordingly, and using log notation: