Experimental study on the relationship between Specific Absorption Rate and RF conducted power for LTE wireless devices

Specific Absorption Rate (SAR) testing of 4G/LTE mobile devices shows a greater complexity than that of previously available radio equipment. Because of the many parameters of 4G signal, the number of possible measurement conditions has become so large that time and cost of regulatory compliance protocols have easily tripled in the past few years. Based on an experimental investigation of the relationship between conducted power at device amplifier output and peak spatial-average SAR, this paper deduces important characteristics of the LTE mode yielding the highest exposure in a given band. It also exhibits how quasi-proportionality between SAR and conducted power can be used to support significant test reduction. The reported results were used as a basis for the development of LTE SAR standard measurement procedures at the International Electrotechnical Commission (IEC) level.