SAR Reduction and Antenna Performance Guarantee by Suppression of Surface Currents on Portable Telephones

摘要

This paper describes a means for reducing thequantity of electromagnetic radiation absorbed by a human headfrom a portable telephone without degrading the antennaperformance. The method is based on the suppression of currentsflowing on the surface fo the device close to the head by meansof a ferrite sheet attachment, for example. This currentsuppression does not significantly affect the antenna's radiationefficiency, because the ferrite sheet attachment only very slightlyaffects the currents in the antenna and on the other surfaces of thedevice. In this way, a portable telephone with lowelectromagnetic absorption can be realized by controlling thecurrent distribution on its surface.