Reduced deposition and improved system performance of radiating system in presence of human head

At the end of 2005, there were more than 180 million wireless subscribers in the US and over 2 billion worldwide. Despite this incredible popularity, health concerns associated with mobile communication technology arose in the mid 1990s. Since that time, numerous studies and research activities have been executed and continue today. A major thrust of current research focuses on possible links between mobile phone use and certain types of cancers and tumors.This is the motivation to develop a method to design mobile communications antennas that simultaneously reduce the deposited energy on the user and achieve the needed performance. The specific goal of this work is to find the parameters of two or more Hertzian dipoles located on a equi-radius Gaussian surface that significantly reduces the deposited energy within the head model, while, at the same time, provide adequate farfield performance. This was accomplished by; simplifying the forward solving problem by using a layered sphere as a "head" model, taking advantage of the spherical symmetry of the problem and utilizing a non-linear optimization package to find the parameters of two or more dipoles that reduce the deposited energy in the head and provide for adequate farfield performance.