Limitations for mobile terminals in simultaneous maximization of bandwidth and efficiency in presence of a user

This paper proposes a modal-based analysis of the limitations in simultaneous maximization of the free-space bandwidth of a mobile terminal, and its radiation efficiency in the presence of a user or user model. Among others, this analysis suggests that handset antenna design methods, focused on the optimization of free-space quantities, significantly reduce the possibility to optimize the radio-performances in presence of the user. However, the reduction of energy storage in the close vicinity of the source, as well as the use of well-designed matching circuits, allow to increase the degree of freedom in the reduction of power absorption.