Precise Modeling And Analysis Of The Radiation-induced Heating Effect From The Wireless Transmitter

This paper aims to study the thermal effect on a human head under the radiation of435MHz. Firstly, commercial software Xfdtd6.3is used to built models including theinterphone model, the eye model, the head model and the hand model. The interphonemodel takes Motorola CP1200as a template, and contains several major parts as theenclosure, antenna, battery and PCB board. The eye model contains eight kinds oftissues, which is basically the most sophisticated division of the human eye. Head andhand models are established on the basis of Zubal human model, which is widely usedin similar studies. Through writing a program to process three-dimensional array of thehuman body model established by Zubal professor, the model is got which is not onlyneeded in this article but also can be directly called in Xfdtd6.3. Secondly,three-dimensional rotation technique is used to combine the human body model, andset the electromagnetic parameters of various human tissues in435MHz. We useXfdtd6.3to calculate the combined model, and split the model with a non-uniform grid,the resolutions are0.25mm and1mm for eyes and other body tissues respectively, inorder to achieve SAR distribution of the human head under the continuous sine waveradiation. Finally, the non-uniform grid temperature calculation procedure is written inC language based on the bio-heat conduction equation and its boundary conditions, thenwe calculate the temperature field distribution and its change with time. In the Clanguage program, in some cases do some special handling on the model used in thisarticle, including the processing of a variety of organizational boundaries, the humanhead cross-section, and the transition region of non-uniform grid subdivision. To do thatcan not only truly reflect the temperature conditions of a variety of tissues in the humanhead, but also is a breakthrough in computer memory constraints, and reduce thecomputation time.In the irradiation model in this model, when the frequency is435MHz and theinput power is0.5W, the final temperature of the human skin is33.7416℃, and32.6168℃for Cornea.The temperature rise of human skin and cornea caused byelectromagnetic radiation were0.0409℃and0.0412℃, Respectively, and it can befound that the average temperature rise of the skin and eye tissue is much higher thanother organizations.