Compact MIMO antenna for mini-laptop

This article presents the multi-input multi-output (MIMO) antennas with the element of a polygonal loop. The antenna element consists of a half-wavelength inverted-U loop microstrip and an L-shaped ground plane, and has a low profile of 0.08λ₀ at 2.6GHz. Due to the two coupling-currents, which are caused by radiation emission and conduction emission and are 180° out of phase, field cancellation clearly reduces mutual coupling between the closely packed antenna elements. Combining with the characteristics of wide-beam of each antenna element, theoretical and practical investigations on 2-port MIMO antenna for a mini-laptop are implemented and examined experimentally. Experimental results indicate that the proposed designs achieve more than 20 dB isolation between two parallel antenna elements with 1 mm edge-to-edge separation. This characteristic is especially promising for the compact wireless communication terminal with multiple I/O.