Chen Xi Lin, De Santis Valerio, Umenei Aghuinyue Esai
Laboratory of Electromagnetic and Acoustics (LEMA), Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
Phys Med Biol. 2014 Jul 7;59(13):3453-64. doi: 10.1088/0031-9155/59/13/3453. Epub 2014 Jun 3.
In this study, the maximum received power obtainable through wireless power transfer (WPT) by a small receiver (Rx) coil from a relatively large transmitter (Tx) coil is numerically estimated in the frequency range from 100 kHz to 10 MHz based on human body exposure limits. Analytical calculations were first conducted to determine the worst-case coupling between a homogeneous cylindrical phantom with a radius of 0.65 m and a Tx coil positioned 0.1 m away with the radius ranging from 0.25 to 2.5 m. Subsequently, three high-resolution anatomical models were employed to compute the peak induced field intensities with respect to various Tx coil locations and dimensions. Based on the computational results, scaling factors which correlate the cylindrical phantom and anatomical model results were derived. Next, the optimal operating frequency, at which the highest transmitter source power can be utilized without exceeding the exposure limits, is found to be around 2 MHz. Finally, a formulation is proposed to estimate the maximum obtainable power of WPT in a typical room scenario while adhering to the human body exposure compliance mandates.
在本研究中，基于人体暴露限值，在100 kHz至10 MHz的频率范围内，对小型接收器（Rx）线圈从相对较大的发射器（Tx）线圈通过无线功率传输（WPT）可获得的最大接收功率进行了数值估计。首先进行了解析计算，以确定半径为0.65 m的均匀圆柱形模型与距离其0.1 m、半径范围为0.25至2.5 m的Tx线圈之间的最坏情况耦合。随后，使用了三个高分辨率解剖模型来计算相对于各种Tx线圈位置和尺寸的峰值感应场强。基于计算结果，得出了将圆柱形模型和解剖模型结果相关联的比例因子。接下来，发现能够在不超过暴露限值的情况下利用最高发射器源功率的最佳工作频率约为2 MHz。最后，提出了一种公式，用于在典型房间场景中估计WPT的最大可获得功率，同时遵守人体暴露合规要求。
