A Highly-Integrated MIMO Antenna Unit

A novel highly-integrated multiple inputs multiple outputs (MIMO) antenna unit, termed as "Integrated Even/Odd-Mode Antenna" (IEOMA), is proposed in this paper. Despite the small size of the IEOMA antenna, it has two important advantages compared to other smart phone antennas: 1) It is capable of achieving wide-coverage radiation patterns in three dimensions. This is achieved by enabling the antenna to operate at two different modes including the even and odd modes simultaneously, and complementary radiation patterns can be achieved at each mode; 2). This IEOMA antenna can achieve high isolation between two antennas in different modes even if they are overlapped with each other, hence it is suitable for realizing compact-size MIMO antenna systems by using this antenna as the unit element. The concept, antenna configurations and designs are explained in the paper. To verify the concept, one IEOMA antenna at 3.5 GHz is designed and simulated. One prototype of 8X8 MIMO antenna system using the IEOMA antenna as unit element has also been manufactured and measured. Both simulation and measurement results are presented and good agreement between them is observed. The concept of IEOMA antenna opens up a number of areas of potential applications: For example, it will be useful for 5G smart phones, as it can achieve high isolation in compact MIMO systems and overcome the problem of limited coverage of miniaturized antennas in mobile phones; Also it will be useful for Tracking, Telemetry and Command (TTC) sub-systems onboard small satellites as TTC antennas are required to have wide-coverage radiation patterns in 3D. Usually TTC sub-systems onboard small satellites employ several TTC antennas for achieving wide-coverage patterns. As one single IEOMA antenna can achieve wide coverage, a significant reduction of size and mass of TTC antenna systems onboard small satellites can be achieved by using the IEOMA antenna instead of several traditional TTC antennas.