Maximal Ratio Combining Gain of Dual-Band MIMO Antenna for Sub-6 GHz in the Vicinity of User’s Hand and Different Elements Configurations

Abstract

This paper presents results of maximal ratio combining (MRC) technique of dual-band 4-element MIMO antenna with user’s hand in data mode and different placements of antenna elements (AEs) on the chassis. The different placements start from worst case to optimal which is selected to avoid thick tissues of the hand. The dual 5G frequency bands are from 3.3 to 3.8 GHz in the lower band and from 5.2 to 6 GHz in the upper band. Results show that the optimal configuration has free space MRC gain at outage level of 50% in both frequency bands from 0.6 to 2.3 dB, the peak value of this gain is around 86% from the gain of ideal 4-element MIMO system. However, with user’s hand the gain in the lower band starts from -1.18 dB and drops to −5.23 dB but the gain is more stable in the upper band and it increases from −1.33 to −0.68 dB. The gain at the same 50% outage level provided by MRC over the highest single antenna element is around 7 dB without user’s hand but this gain drops in the vicinity of user’s hand to be from 6.16 to 5.5 dB in the lower band and from 5.90 to 6.31 dB in the upper band.