Analysis of a near-field MIMO based on the polarization diversity by using the mode-based approach

According to the MIMO theory, the capacity of a channel can be increased by using multiple antennas at each transmitting and receiving end. In order to construct a near-field 2×2 MIMO system, an antenna array, which is composed of short electric dipoles with different polarizations, can be used. When small antennas are used, the characteristics of the channel matrix can be analyzed based on the addition theorem, and thus the capacity can also be easily estimated.