Li Qingxiang, Gandhi Om P, Kang Gang
Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, UT 84112, USA.
Phys Med Biol. 2004 Sep 7;49(17):4173-86. doi: 10.1088/0031-9155/49/17/024.
Compliance with safety guidelines prescribed in terms of maximum electromagnetic power absorption (specific absorption rate or SAR) for any 1- or 10-g of tissue is required for all newly introduced personal wireless devices such as wireless PCs. The prescribed SAR measuring system is a planar phantom with a relatively thin base of thickness 2.0 mm filled with a lossy fluid to simulate dielectric properties of the tissues. A well-characterized, broadband irradiator is required for SAR system validation or submerged E-field probe calibration for the Wi-Fi frequencies in the 5-6 GHz band. We describe an open-ended waveguide system that may be used for this purpose. Using a fourth-order polynomial least-squares fit to the experimental data gives SAR variations close to the bottom surface of the phantom that are in excellent agreement with those obtained using the finite-difference time-domain (FDTD) numerical method. The experimentally determined peak 1- and 10-g SARs are within 1 to 2% of those obtained using the FDTD both at 5.25 and 5.8 GHz.
所有新推出的个人无线设备，如无线个人电脑，都必须符合规定的安全准则，即任何1克或10克组织的最大电磁功率吸收（比吸收率或SAR）。规定的SAR测量系统是一个平面体模，其底部相对较薄，厚度为2.0毫米，填充有损耗性流体，以模拟组织的介电特性。对于5-6GHz频段的Wi-Fi频率，SAR系统验证或水下电场探头校准需要一个特性良好的宽带辐射器。我们描述了一种可用于此目的的开放式波导系统。使用四阶多项式最小二乘法拟合实验数据，得到的体模底面附近的SAR变化与使用时域有限差分（FDTD）数值方法获得的结果非常吻合。在5.25GHz和5.8GHz频率下，实验测定的1克和10克SAR峰值与使用FDTD方法获得的结果相差1%至2%。
