Isolation Enhancement in Two Port Mimo System Using Parallel Coupled Lines

Abstract

In this paper, we implemented a parallel line coupled resonator for isolation enhancement in multiple-input-multiple-output (MIMO) antenna system for WLAN application. The edge-to-edge spacing between antenna elements is 3. $8mm (0.072\lambda_{o}, \lambda_{o}$ is the free space wavelength at 5.7GHz).The decoupling structure consists of parallel coupled resonator structure acting as band reject filter that helps to nulliry the near coupled field between antenna system. The parametric study is done to optimize the length of coupled resonator so as to obtain high isolation between antenna elements at resonating frequency. The simulated efficiency remains above 88% along with envelope correlation coefficient (ECC) value lower than 0.03, making the design practicable for MIMO WLAN application.