The focusing of a magnetic field, at low frequencies, in the very near field is difficult as flux lines naturally tend to disperse. It is not possible to use antenna array techniques due to large wavelengths at low frequencies. A method for synthesizing a concentrated magnetic field in a large air gap between two magnetic poles is presented. The focusing effect is brought about by the inclusion of side poles, adjacent to each of the main poles. Through the correct dimensioning of the side poles' reluctances and relative magneto-motive forces it is possible to focus the field in the center of the gap. General design curves for normalized parameters, determined via finite element modelling, are presented. A scale model is experimentally verified.
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