Physics of multi-antenna communication systems

This chapter presents a concern regarding the nature of wireless communications using multiple antennas. Multi-antenna systems are mainly developed using array processing methodology mostly derived for a scalar rather than a vector problem. However, as wireless communication systems operate in microwave frequency region, the vector nature of electromagnetic waves cannot be neglected in any system design levels. Failure in doing so will lead to an erroneous interpretation of a system performance. The goal of this chapter is to show that when the vector nature of electromagnetic wave is taken into account, an expected system performance may not be realized. Therefore, the electromagnetic effects must be integrated into a system design process in order to achieve the best system design. Many researches are underway regarding this important issue.