Influence of human head and hand on PIFA antenna matching properties and SAR

The paper analyzes the influence of human head and hand on planar inverted F antenna (PIFA) matching properties. Since PIFA is a very popular design in mobile applications, it is of primary importance to analyze the matching of such an antenna in real application scenarios (close to the head, grasped by the hand). Any matching deviation leads to the reduction of radiated power which should be accounted for in the system design. SAR in user's head was also calculated for the standalone antenna and the antenna grasped by user's hand. The analysis was done for a linearly tapered PIFA antenna in the 900 MHz frequency range. Such antenna was simulated and realized. Its gain, radiation pattern, SWR and S
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were simulated and measured for free-space conditions. The antenna matching parameters (S
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and SWR) were then simulated and measured for three different realistic scenarios. Difference in SAR in human head was calculated for the cases of stand-alone and hand-grasped antenna. Simulations were done using SEMCAD X, which provided the anatomically realistic model of human hand and the model of SAM head phantom. Both the simulated and measured results showed that the human hand and head considerably affect the antenna matching parameters, resulting in both matching and SAR variations.