A compact MIMO antenna of meander-line structure for Wi-Fi application

Abstract

In this paper, we develop a multiple-input-multiple-output (MIMO) Wi-Fi antenna for mobile application. The MIMO antenna system consists of two monopoles of meander-line structure. The separation between two antenna elements is 20 mm which is approximately 0.33λ0 at 5 GHz. Two U-shaped slots are used to produce defective ground structure (DGSs) to reduce the mutual coupling between two monopoles. In this way, the return loss and isolation of the MIMO system can be improved. The designed antenna has coupling isolation of higher than 22 dB in operating band. The bandwidth of 25% with |S11|≤ -10 dB is achieved from 4.9 to 6.3 GHz frequency range. It covers the Wi-Fi band from 5.2 to 5.8 GHz. The directive efficiency of developed antenna is higher than 89% for operating band. The lower efficiency loss shows the effectiveness of designed antenna.