Frequency Reconfigurable Four Port MIMO Antenna for Wi-Fi, WLAN and ISM Applications

This study focuses on improving data rates in wireless networks through the design, simulation and measurement of a frequency reconfigurable four port MIMO antenna. The antenna is specifically developed for Wi-Fi, wireless local area network, and Industrial, scientific and medical applications. The antenna design has microstrip patch components, a closely built decoupling structure, an electromagnetic band gap structure, and a defective ground structure. These features enhance the antenna's MIMO performance at specific frequencies of operation and minimize radiation losses. The antenna design includes an RF PIN diode to allow for reconfigurability. This enables the antenna to operate at resonating frequencies between 2.39 and 5.36 GHz while the diode is in the ON and OFF states, respectively. The MIMO antenna under consideration is assessed on a FR4 substrate of 70x65.5mm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$70 \times 65.5\;{\text{mm}}<^>{2}$$\end{document} and the wavelength is 0.56x0.53 lambda 0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0.56 \times 0.53\lambda_{0}$$\end{document}. It achieves a peak gain of 7.3 dBi at 2.39 GHz and 8.2 dBi at 5.36 GHz. The simulated results are implemented using HFSS and measured using network analyser KEYSIGHT N9951A. The bandwidths achieved are 0.07 at 2.39 GHz and 0.53 at 5.36 GHz. The experimental results on analysing various antenna characteristics are observed as Total active reflection coefficient value less than 0 dB, envelope correlation coefficient less than 0.5, Mean effective gain value less than - 3 dB, etc. The gain of the proposed four port reconfigurable MIMO antenna is 10% improvement when compared with existing works. The results from the simulated and measured matches well within the two operating bands, indicating that the suggested topology could be used for 5G communications.