A compact UWB printed monopole MIMO antenna with mutual coupling reduction

Abstract

A compact multiple-input-multiple-output (MIMO) antenna with very high isolation is proposed for ultrawideband (UWB) applications. The antenna with a compact size of 30.1 × 20.5mm2 (0.31λ0 × 0.21λ0) consists of two planar-monopole antenna elements. It is found that isolation of more than 25 dB can be achieved between two parallel monopole antenna elements. For the lowfrequency isolation, an efficient technique of bending the feed-line and applying a new protruded ground is introduced. To increase isolation, a design based on suppressing surface wave, near-field, and far-field coupling is applied. The simulation and measurement results of the proposed antenna with the good agreement are presented and show a bandwidth with S11 ≤ -10 dB, S12 ≤ -25 dB ranged from 3.1 to 10.6GHz making the proposed antenna a good candidate for UWB MIMO systems.