Performance analysis of broadband coupling - element - based multiantenna structure for mobile terminal with hand effects

This paper presents a comprehensive simulation study on the performance of broadband coupling-element-based multiantenna structures on a mobile terminal at the 2000 MHz Universal Mobile Telecommunications System (UMTS) frequency band with varying two significant hand effects; vertical position of hand along terminal chassis, and distance between hand palm and terminal chassis. The results reveal that there exists an MEG imbalance between antenna elements due to hand effects and it is shown that an MEG imbalance of 3.7 dB lead to a reduction of 1.9 dB in diversity gain at 99% reliability level using maximal ratio combining (MRC) technique. For a two-element antenna configuration, the impact of MEG imbalance on diversity gain is more significant when only one antenna element is in close proximity to the hand, compared to when both antenna elements are in the presence of the hand. It is also shown that a broadband multiantenna structure with elements vertically oriented along the edges of a small 100 mm x 40 mm mobile terminal chassis achieves better performance in port-to-port isolation, MEG imbalance and diversity gain compared to other studied multiantenna configurations when the user´s hand is present.