Investigation of a Triple-Band Multibeam MIMO Antenna for Wireless Access Points

A triple-band multibeam multiple-input multiple-output (MIMO) antenna is investigated for access points (APs). The triple-band antenna covers 2.4-2.5, 3.4-3.7, and 5.1-5.9 GHz frequency bands with high gains and directional radiation patterns for WLAN/WiMAX applications. The MIMO antenna consists of four triple-band antenna elements rotated around a circle for space and polarization diversities. The multibeam antenna is composed of four MIMO antenna units for the coverage of a conical area. The triple-band multibeam MIMO antenna is designed and the MIMO performance is evaluated. It is shown that low capacity loss and high diversity gain can be obtained with the low correlation and low branch power ratio between the MIMO antenna units. It is found that the four-beam MIMO antenna is suitable for large public places with high density clients where enhanced frequency reusability and reduced maintenance efforts are preferred.