A compact planar MIMO antenna system of four elements with similar radiation characteristics and isolation structure
A compact planar multiple-input-multiple-output (MIMO) antenna system of four elements with similar radiation characteristics is proposed for the whole 2.4-GHz WLAN band. It consists of two proximity-coupled fed microstrip square ring patch antennas and two lambda/4 microstrip slot antennas of the same linear polarization. These two types of antennas are printed on different sides of the substrate