Evaluation of power deposited in a homogenous head model for clam-shell type cellular phones

The fundamental dosimetric quantity used to measure the level of exposure due to cellular phones is the Specific Absorption Rate (SAR). The compliance of a device to the exposure limit is determined by following the guidelines described in IEEE measurement standards. The compliance assessment process can be quite complicated and time consuming, due to the many different test conditions that have to be considered and the slow speed of the measurement equipment. Depending on the frequency, use configuration of the device and form factor the SAR values can vary significantly from test case to test case even for the same device. This work shows that for a particular form factor, indicated as clam shell, where the phone is made of two halves that rotating around a hinge, one of the required test condition, described as tilt position, always provides lower SAR values than touch position, the other test condition. Different frequencies, antenna locations and antenna types have been considered. The results obtained with the well-known Finite Difference Time-Domain (FDTD) method have been validated with measurements. A robotic assessment tool (DASY4) is used for measurement purpose