High Isolation Improvement in a Compact UWB MIMO Antenna

TL;DR

This paper presents a compact UWB MIMO antenna with over 25 dB isolation across a broad frequency range, achieved through innovative design techniques like bending the feed-line and protruded ground, suitable for high-performance wireless systems.

Contribution

The paper introduces a novel compact UWB MIMO antenna with high isolation using specific design strategies to suppress coupling, expanding the potential for efficient UWB communication systems.

Findings

Achieves over 25 dB isolation across 3.1-10.6 GHz

Maintains bandwidth with S11 < -10 dB and S12 < -25 dB

Demonstrates good agreement between simulation and measurement

Abstract

A compact multiple-input-multiple-output (MIMO) antenna with very high isolation is proposed for ultrawide-band (UWB) applications. The antenna with a compact size of 30.1x20.5 mm^2 (0.31${\lambda}_0$ x0.21${\lambda}_0$ ) 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 low-frequency 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 S 11 < -10 dB, S 12 < -25 dB ranged from 3.1 to 10.6 GHz making the proposed antenna a good candidate for UWB MIMO systems.