Optimization of plane-wave power absorption in lossy media

The phenomenon of microwave power absorption has recently become of increased scientific and public interest, particularly in the area of cellular communication. Electromagnetic power absorption in biological tissues is a well-known phenomenon. Its evaluation requires, in general, a solution of the 3D frequency-dependent wave equation in complex configurations, which may necessitate quite massive analytical and numerical efforts. Herein, we focus on a simplified 1D model corresponding to normal-incidence of plane-waves upon a lossy half-space. Our model establishes a tight estimate on the maximal (optimal) power absorption in realistic mobile phone - human head configurations. Furthermore, the absorption efficiency as well as the source impedance are obtained via an explicit closed-form expressions, leading to an explicit optimal power absorption (worst-case/best-case) criteria for highly lossy tissues