Effect of User Head on Mobile Telephone Handset Antenna Impedance and Head Internal Fields Distribution

It is shown that, by approximating a human head as a dielectric sphere, the method of spherical wave expansions can be used to obtain useful predictions of interactions between the head and an adjacent handset antenna working at about 2 GHz. The fields are computed by an essentially analytical method based on spherical wave expansions. The intention is to obtain an approximate, computationally efficient, tool which could be used for antenna engineering, and it is fully accepted that fine structure in head, and the effect of the neck and body, would be neglected. This work is therefore complementary to those studies using very accurate head models.