Design and Analysis of a Compact UWB-MIMO Antenna with Improved Isolation for UWB/WLAN Applications

Abstract

For space limited ultra-wideband (UWB) communication system, the small foot print of the multi-input multi-output (MIMO) antenna is highly desirable. A significant subject of the investigation is the creation of a small MIMO antenna with enhanced isolation and large operating bandwidth. To accomplish this object, a compact size two-port UWB-MIMO antenna is presented in this article. The proposed antenna consists of opposite faced semi-circular monopole radiating elements. The opposite orientation of the radiating elements is offered low envelope correlation coefficient (ECC) and good pattern diversity. The improved bandwidth and enhanced isolation are achieved by etching the ground plane with a rectangular defected ground structure structure. Antenna size optimization is taking placed with evolution of the compact size single UWB antenna element. The computer simulation tool is used to complete the design and optimization process. The optimized size of the proposed antenna is 20 × 20 mm2 or electrical size of 0.469 λ0 × 0.469 λ0. The fabricated prototype of the antenna is experimentally evaluated and validated by the comparison of the simulated and measured results. However, obtained results show well agreement. The proposed antenna has extended UWB bandwidth 2–12 GHz (fractional bandwidth of 142.8%) and improved isolation of less than 25 dB, and low value of ECC (0.05). The antenna size, isolation, operating bandwidth, and ECC are compared with previously reported work. Furthermore, the proposed antenna is preferable for WLAN and UWB applications.