Zhao Lei, Cui Tie Jun
Center for Computational Electromagnetics and the State Key Laboratory of Millimeter Waves, Department of Radio Engineering, Southeast University, Nanjing 210096, People's Republic of China.
Phys Rev E Stat Nonlin Soft Matter Phys. 2005 Dec;72(6 Pt 1):061911. doi: 10.1103/PhysRevE.72.061911. Epub 2005 Dec 19.
An enhancement of the specific absorption rate (SAR) inside a lossy dielectric object has been investigated theoretically based on a slab of left-handed medium (LHM). In order to make an accurate analysis of SAR distribution, a proper Green's function involved in the LHM slab is proposed, from which an integral equation for the electric field inside the dielectric object is derived. Such an integral equation has been solved accurately and efficiently using the conjugate gradient method and the fast Fourier transform. We have made a lot of numerical experiments on the SAR distributions inside the dielectric object excited by a line source with and without the LHM slab. Numerical experiments show that SAR can be enhanced tremendously when the LHM slab is involved due to the proper usage of strong surface waves, which will be helpful in the potential biomedical applications for hyperthermia. The physical insight for such a phenomenon has also been discussed.
基于左手介质(LHM)平板,从理论上研究了有损电介质物体内部比吸收率(SAR)的增强情况。为了准确分析SAR分布,提出了一种与LHM平板相关的合适格林函数,由此推导出电介质物体内部电场的积分方程。利用共轭梯度法和快速傅里叶变换对该积分方程进行了精确有效的求解。我们对有无LHM平板情况下线源激发的电介质物体内部的SAR分布进行了大量数值实验。数值实验表明,由于强表面波的合理利用,当引入LHM平板时,SAR可大幅增强,这将有助于热疗在潜在生物医学应用中的发展。还讨论了这种现象的物理见解。