Design of a Compact UWB-MIMO Antenna with Isolation Enhancement through Extended Elliptical Ground Plane

Abstract

This paper deals with the design of a Multiple Input Multiple Output (MIMO) antenna for UWB applications. It is composed of two identical radiating elements (parallel monopoles) symmetrically arranged on a FR-4 substrate. The monopoles are closely spaced (about 0.2 Lambda, center to center). A decoupling mechanism based on vertical extension of the Ground plane with elliptical edges (stub) allows to achieve high isolation (>20 dB). Further, the designed system presents good diversity performance, as the obtained Envelope Correlation Coefficient is less than 0.01. The antenna array is compact (36x30 mm2), with ultra-wide operating frequency range (2.6 to 10.8 GHz). Simulations and measurements demonstrate good agreement. The obtained results make the proposed structure a good candidate for any UWB applications and modern wireless communications systems thanks to its wide frequency band, compactness and performance.