MUTUAL COUPLING REDUCTION IN STACKED STAR MIMO ANTENNA FOR WLAN AND ITU BAND APPLICATIONS

Abstract

A two-port novel Stacked Star multiple-input multiple-output (MIMO) antenna with a physical size of 46 × 23 × 3.2 mm³ is proposed. The proposed MIMO is designed for wireless communication applications such as Wireless Local Area Network (WLAN) and International Telecommunication Union (ITU) band resonating at 5.4 and 8.5 GHz, respectively. The Star is designed by using a basic circular antenna, from which Star geometry is constructed with iterations to obtain the desired frequency bands using Rogers RT5880 with a thickness of 1.6 mm for Stacked Star. The Stacked Star structure allows a wide bandwidth at the desired frequencies of 5.2-5.5 GHz and 8.2-8.6 GHz, respectively. To minimize mutual coupling, a T-slot stub is placed between the radiating patches. The proposed structures are simulated using Computer Simulation Technology. The proposed design is fed with proximity feed coupling for good impedance matching. Further, it provides an improved isolation of -8 dB. The important characteristics of the antenna such as reflection coefficients, Voltage Standing Wave Ratio, surface current distributions, and radiation patterns, are examined. In addition to that, MIMO characteristics elements like envelope correlation coefficient (ECC), and diversity gain (DG) and group delay -11.3 and -14.2 ns are investigated. The ECC is less than 0.01, while the DG is near 10 Db, indicating good MIMO performance. The anechoic measurement chamber and Schwarz ZVL vector network were used to measure the target MIMO antenna. The simulated and measured result shows a high degree of similarity so that the proposed antenna is strongly suggested for WLAN and ITU bands.