x3 Scale-model experiments on a slot-based directivity control built-in antenna sytem for mobile terminals

In the field of mobile communication, the used of Multiple-input Multiple-output (MIMO) systems to increase channel capacity has received increasing attention in recent years. In these systems, antennas play an important role, since antenna´s radiation characteristics are inherently included in the communication channel between the transmitter and the receiver. Especially, the increased mutual coupling between built-in antennas will affect the radiation efficiency and correlation of the antennas. To reduce mutual coupling and correlation between antennas, element-separation of more than half wavelength is required [1]. However, small sized terminals will often be required in real applications and limited space makes element-separation difficult to achieve.