Effects of ear-connection modeling on the electromagnetic-energy absorption in a human-head phantom exposed to a dipole antenna field at 835 MHz

Specific absorption rate (SAR) compliance measurements for wireless personal devices are usually performed in anatomically correct phantoms. The phantoms have a lossless spacer to model the external ear (pinna). The use of a lossless spacer has been questioned. The purpose of this paper was to study the effects of the lossy pinna by E-field and numerical assessments validated with thermal measurements. The measurements were performed in a box with a rectangular well simulating a pinna compressed during phone usage. Various openings were created in the septum separating the box and the well to simulate the connection between the head and pinna. A balanced half-wave dipole was used as the RF source. The results of this study lead to the conclusion that for SAR values averaged over 1 gram, within our current probe resolution, complicated lossy pinna structures are not necessary.