Formation of Hot Spots in Multilayer Spheres

A theoretical study of the distribution of the normalized heating potential resulting from a plane wave incident in a multilayered sphere simulating a human head with skin, fat, bone and brain tissue layers has been undertaken. It was found that for spheres of radii 10 cm and 5 cm a relative peak of the normalized heating potential occurs in the vicinity of the center of the sphere. For the case of the 5 cm sphere in the range of frequencies 400 MHZ to 2.76 GHZ the maximum value of the heating potential occurs at the center suggesting the possibility of a hot spot. A comparison between the multilayer and a single layer model shows that the maximum values of the heating potential are the same.