MIMO-configured WLAN access point antenna with high port isolation

Abstract

A four-element MIMO (multiple-input multiple-output) antenna system utilizing planar inverted-F antenna for 5 GHz WLAN (wireless local area network, band 1: 5.15–5.35 GHz, band 2: 5.725–5.825 GHz) access point applications is presented in this paper. The detrimental effects of practical device environment on the antenna isolation performance are compensated using an array of metasurface-based isolator between the antenna elements. The proposed isolator partially absorbs the fields responsible for coupling and rotates the polarization of rest of the coupled fields. The working mechanism of the proposed isolator is explained with the surface current distribution. The proposed antenna also exhibits spatial/pattern diversity and thus, the lower values of envelope correlation coefficient make it suitable for the MIMO application.

Keywords:

• Metasurface
• MIMO antenna
• mutual coupling
• planar inverted-F antenna
• WLAN access point