Bounds and estimates for power absorption and radiation efficiencies of cellular handsets

This paper presents a model of a cellular handset closely coupled to highly lossy human head which renders explicit closed-form expressions for the power absorption and radiation efficiencies, associated with the generalized transmission-line model. These expressions establish tight bounds and estimates for realistic configurations which correlate well with recently reported electric dipole antenna data. Our model should be regarded as the first-order prototype, composed of a cellular "planar" phone (electric current-sheet) in the close vicinity of a human "flat" head, which can be extended, via the so-called Leontovich surface impedance to canonical 3D shapes. This approach has already been successfully utilized in some scattering problems involving elementary sources.