Simulation And Experiment Study Of SAR By Handle Wireless Communication Equipments' EM Radiation

As mobile phone, wireless phone, Bluetooth earphone and such RF communication equipments have been widely used, people are more and more worry about the healthy effect caused by the EM radiation of such RF equipments which operating press close to people's head. Such handle wireless communication equipments carry out communication by radiating microwave energy in the space. While communicating, the antenna gets close to people's check and the microwave radiation directly act on the head. When the energy absorbed by people exceed some limitation, it will bring some serious effect on nerve system, blood and immunity system, lens and other apparatus.It usually takes SAR, Specific Absorption Rate, to evaluate human absorbed EM energy radiated by handle wireless communication equipments. SAR could be tested by electronic field probe in the tissue-equivalent liquid, and also could be calculated by EM numerical calculation method, such as FDTD(Finite-Difference Time-Domain) method.In allusion to the SAR of handle wireless communication equipments' near-field radiation, IEC, ETSI and such international standard organizations have worked out the general and basic standards for testing and numerical calculation. They are keeping on perfecting related product standards. In contradiction to costly, long period and other disadvantage of real test, numerical simulation technique has obvious superiority and it adapts to terminal design, R&D, preauthentication and other stages. In various EM numerical calculation method, FDTD method has been widely used in the biological EM absorption dosimetry. Because its operation and storage room are in direct ratio to the number of grid, satisfying boundary condition automatically, adapt to calculate complex component in the near-field and other advantages. In this paper, it takes simple dipole antenna to discuss the head's energy absorption principle in the near-field and compared it to testing results, then gives some suggestions to improve the simulation precision.