The promise of increased capacity without extra spectrum or power requirement has made smart antenna system and multiple input multiple output (MIMO) antenna systems one key research area for investigation. The health issue on the exposure of humans to electromagnetic radiation is also becoming a wide concern associated with the use of wireless communication devices. Specific Absorption Rate (SAR) is one of the most widely used parameters for evaluation of human electromagnetic exposure. There are standards that regulate the level of energy exposure to the humans. Having low energy absorption also means an improvement to the efficiency of the system and a longer battery life for the phone. Therefore it is essential to have proper design of antennas with low SAR for use in handsets ....[ Read more ]

The promise of increased capacity without extra spectrum or power requirement has made smart antenna system and multiple input multiple output (MIMO) antenna systems one key research area for investigation. The health issue on the exposure of humans to electromagnetic radiation is also becoming a wide concern associated with the use of wireless communication devices. Specific Absorption Rate (SAR) is one of the most widely used parameters for evaluation of human electromagnetic exposure. There are standards that regulate the level of energy exposure to the humans. Having low energy absorption also means an improvement to the efficiency of the system and a longer battery life for the phone. Therefore it is essential to have proper design of antennas with low SAR for use in handsets .

The purpose of this thesis is to investigate the effect of smart antennas on Specific Absorption Rate at 1.9GHz frequency band. We emulate the operation of the smart antennas by applying different signal phases to a mobile telephone prototype configured with a PIFA antenna. The SAR of this model is simulated using Finite Difference Time Domain (FDTD) method and measured experimentally using the MapSAR platform. It is found that the operation of smart antennas on SAR will have a significant impact, with SAR changing by both 50% greater or less for varying signal phases.

The effect of distance and frequency to SAR is also evaluated and the same observation results. By appropriately selecting the phase to feedings, a decrease in the SAR value can be achieved and it can be a convenient way to reduce the SAR to meet the safely limits in various standards.