A Wideband Study of the Bandwidth, SAR and Radiation Efficiency of Mobile Terminal Antenna Structures

Abstract

In this paper, the frequency dependence of bandwidth, SAR and radiation efficiency of mobile terminal antennas are studied at wide frequency range, from 0.6 GHz to 6 GHz. Two antenna models are studied with simulations in free space and in talk-position beside a head model and two hand models. The results show a connection between chassis resonant frequencies, impedance bandwidth, SAR, and radiation efficiency, increase in SAR and decrease in radiation efficiency occur when bandwidth reaches its maximum due to a chassis resonance. Above 3 GHz this trend is shown to be not valid any more, as radiation of the antenna/coupling element become dominant. The results of the paper provide novel and useful information for the antenna designers of future mobile terminals