Antenna design for 4-by-4 MIMO communication

This paper presents the physical implementation of an antenna system for 4-by-4 MIMO communication. Considering the size of the typical antenna for LTE-band wireless communication, it is very difficult to increase the number of the radiators more than two and integrate them in a limited volume of the smart phone. To circumvent this difficulty, compact radiators are designed based on the zeroth-order effect and placed in their vicinity. At the same time, these antenna elements are decoupled through the trapping structure for a high isolation. Further, a pair of chip antennas is developed and put together with the zeroth-order antennas, while all the radiating elements have good isolation performances, which is one of the key-factors to the MIMO system.