Capacity enhancement using fixed phase difference feeding in a handset MIMO antenna including human body effects

In a handset MIMO (Multiple Input and Multiple Output) antenna, small number of elements and ports are desired. To achieve large channel capacity in above situations, adjustment of radiation patterns is important. We focus on analog techniques, and apply phase difference feeding to a handset MIMO antenna including human body effects. The phase difference is decided and fixed based on MEG (Mean Effective Gain) and correlation coefficient. The results of propagation analysis show that channel capacities with optimum phase difference are larger than that without phase difference in all the angles of incoming wave. This result indicates that the enhancement can be achieved by fixed phase difference, namely simple feeding circuits such as delay lines.