Diversity antennas efficiencies enhancement

In this paper, a new method for enhancing ultra miniature diversity antennas efficiencies is shown. Antenna diversity is evaluated in terms of envelope correlation coefficient and diversity gain. Diversity gain can be related to antenna efficiencies. The so obtained diversity gain is called "efficient diversity gain". It is shown that the lower the mutual coupling, the higher antennas efficiencies, and the higher antennas efficiencies, the higher efficient diversity gains. To do so, a method to reduce mutual coupling between the antennas is developed by inserting a slot in the printed circuit board (PCB). The performances of the diversity handheld systems with and without slot are compared in terms of envelope correlation coefficient and efficient diversity gain. The advantage of this method lies in it easily implementation at the terminal side of a wireless link to obtain enhanced diversity antennas.