MIMO antenna for mobile terminals with enhanced isolation in LTE band

Abstract

A MIMO antenna system comprising of two antenna elements is proposed for utilization in Long Term Evolution (LTE) frequencies for mobile terminals. The antenna element is a coupled fed printed monopole capable of functioning at LTE 2300 on a printed circuit board. The antennas are located symmetrically on the top side of the circuit board. The substrate used here is FR4 which possesses a relative permittivity of 4.4 as well as a loss tangent of 0.02. In order to reduce the mutual coupling between the antennas, a decoupling structure consisting of a ground branch is introduced which extends into the non-grounded region below the substrate. The overall dimensions of the system are 65 × 90 × 0.8 mm ³ , with each antenna element having an area of 24 × 14 mm ² . The isolation achieved over the frequency band for the antennas leads to an envelope correlation coefficient value which is less than 0.01.