MIMO antenna systems can greatly improve the capacity and transmission rate of wireless communication. In this letter, two four-port multiple-input-multiple-output (MIMO) antenna systems are proposed in mobile devices...MIMO antenna systems can greatly improve the capacity and transmission rate of wireless communication. In this letter, two four-port multiple-input-multiple-output (MIMO) antenna systems are proposed in mobile devices. An algorithm of calculating envelope correlation (ρe) between antenna units is also proposed. By this algorithm the ρe of the PIFA-MIMO antenna system has been calculated. First, a PIFA-MIMO antenna system is designed for ISM (2.4 GHZ) application. The slots are etched on the ground and the antenna units are placed in such a way that the polarization diversity is exploited to enhance the impedance matching and isolation. Based on this, a printed wideband MIMO antenna system is proposed for portable 3G and 4G applications by means of multi-branch and the defect of ground technology, increasing the bandwidth and reducing mutual coupling between the antennas. The simulation results show that the return loss and isolation of the two antenna systems can meet the performance requirements of the antennas in the mobile phone.展开更多
文摘MIMO antenna systems can greatly improve the capacity and transmission rate of wireless communication. In this letter, two four-port multiple-input-multiple-output (MIMO) antenna systems are proposed in mobile devices. An algorithm of calculating envelope correlation (ρe) between antenna units is also proposed. By this algorithm the ρe of the PIFA-MIMO antenna system has been calculated. First, a PIFA-MIMO antenna system is designed for ISM (2.4 GHZ) application. The slots are etched on the ground and the antenna units are placed in such a way that the polarization diversity is exploited to enhance the impedance matching and isolation. Based on this, a printed wideband MIMO antenna system is proposed for portable 3G and 4G applications by means of multi-branch and the defect of ground technology, increasing the bandwidth and reducing mutual coupling between the antennas. The simulation results show that the return loss and isolation of the two antenna systems can meet the performance requirements of the antennas in the mobile phone.