Three-Dimensional Cylindrical Design Multiple-Input-Multiple-Output/Diversity Antenna With High Isolation For Wireless Communication Applications

In this article, a three-port nonplanar multiple-input-multiple-output/diversity antenna with very high isolation between the radiating elements is presented. To realize diversity from the proposed three-dimensional (3-D) antenna configuration, three monopole radiating elements are arranged at an angle of 120 degrees. The isolation between the radiators is enhanced by using a multilayered cylindrical decoupling structure and defected ground structure (DGS). The DGS reduces the coupling due to surface waves while the cylindrical decoupling structure reduces the coupling due to space waves. The proposed antenna offers consistent pervasive connectivity in the wireless communication environment due to its 3-D geometry with multiple radiating elements and good diversity performance. The prototype is fabricated and measured result shows that more than 42 dB isolation is obtained at the center frequency 1.45 GHz. An increment of 1.2 dBi in the antenna gain is also achieved by using DGS and decoupling structure arrangement. The proposed antenna can be easily placed inside the cylindrical housing or it can be integrated with the existing electronics chip, thus nullifying the requirement for dedicated location in the system.