شبیه سازی تشعشع گوشی تلفن همراه دو باندی درمجاورت مدل آناتومیک سر انسان و محاسبه توزیع SAR متوسط یک گرم

Introduction: In recent years, the rapidly increasing use of mobile phone operating nearby the human head has caused public concern for its effects on human health. The FDTD methodology is widely used for calculation of the effects of electromagnetic fields on human body. Methods and Materials: In this paper, first a dual band patch antenna structure (GSM-900 and DCS 1800), which is located in a plastic box, has been designed and simulated using FDTD method. Then, we use an anatomical model of human head with 21 kinds of tissues contains a set of MRI images of a healthy 35-years-old man. To simulate the effects of radiation of handheld phone on human head using FDTD, we insert the simulated model of mobile phone in vicinity of the anatomical model of human head. The output power of antenna is set in 600 and 250 mW at 900 and 1800 MHz, respectively. Results: Dual-band patch antenna has been simulated in touch position with the human head model using FDTD and the electric field distributions have been obtained in different slices of the head model. Using the obtained results, local SAR and 1-gr averaged SAR distribution have been calculated. It is seen that the peak of 1-gr averaged SAR is obtained as 1.795 and 0.4683 W/kg at 900 and 1800 MHz, respectively. The calculated values of SAR are less than the allowable value of SAR (2 W/kg). Discussion and Conclusion: It is observed that the electric field is mostly concentrated on the ear and brain tissues at 900 MHz while the peak of electric field occurs in the skin region at 1800 MHz. The peak of local SAR occurs in the central region of ear tissue in direct touch of upper side of handheld mobile phone at 900 and 1800 MHz. To validate the proposed method, the mobile phone in the proximity of the spherical head phantom has been simulated and the results have been compared with the results of XFDTD and CST software.