PROXIMITY-FED MIMO ANTENNA WITH TWO PRINTED IFAS AND A WIDEBAND T-SHAPED NEUTRALIZATION LINE

Abstract

A proximity-fed MIMO (multiple-input-multiple-output) antenna with two printed IFAs (inverted-F antennas) and a wideband T-shaped neutralization line is presented. Each element printed IFA is fed by a proximity-fed structure which provides a parameter to control the return loss without efiect on the isolation of the two IFAs. The wideband T-shaped neutralization line, which consists of two meandered branches and a rectangular grounded branch, can enhance the isolation of the two IFAs over a wide operation band (2.35{3.75GHz). The two meandered branches are connected to the two IFAs, respectively, and the rectangular branch is connected to the ground plane. There are two parameters to adjust the isolation without efiect on the return loss. Therefore, the operational bandwidth and the isolation of the proposed antenna can be controlled independently. A bandwidth of 46% with VSWR • 2 and isolation ‚ 20dB from 2.35 to 3.75GHz is achieved. The MIMO antenna of compact size 40£14mm 2 is suitable for application in mobile phones. Moreover, the ground plane size can be changed for applying the proposed antenna in difierent handsets. The results, including S-parameters, radiation pattern, mean efiective gain (MEG), radiation e-ciency, complex correlation coe-cient and the efiects of human hand and head, indicate the proposed MIMO antenna can provide spatial and pattern diversity.