Internal wideband monopole antenna for MIMO access-point applications

A MIMO system utilizing three compact wideband monopole antennas stamped from a metal plate in a wireless access point has been proposed, constructed and studied. The obtained bandwidths of the antennas all cover both the 2.4/5-GHz WLAN and 2.5/3.5/5-GHz WiMAX bands. The results show that the isolation between any two antennas is less than -20 dB across the operating bandwidth. The three-antenna MIMO system has three highly isolated ports with an envelope correlation of less than 0.002. Good radiation characteristics of the antenna have been also observed.