Manipulating MIMO propagation environment using tunable passive repeater

A Multiple-Input-Multiple-Output (MIMO) channel manipulation using tunable passive repeater is presented in this paper. The passive repeater has multiple antennas and each of them has a phase-shifter function. The MIMO channel capacity is maximized by controlling all elements individually in the passive repeater. The effectiveness of the proposed passive repeater is evaluated numerically and experimentally. From these results, it is found that the MIMO channel capacity can be improved by about 40 % due to the tunability of the passive repeater.