Design of Highly Isolated Compact Antenna Array for MIMO Applications

Tiancong Huang,Lijun Yi,Yantao Yu

doi:10.1155/2014/473063

Tiancong Huang, Lijun Yi + Show 1 more

Open Access

https://doi.org/10.1155/2014/473063

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Abstract

In order to achieve very high data rates in both the uplink and downlink channels, the multiple antenna systems are used within the mobile terminal as well as the base station of the future generation of mobile networks. When implemented in a size limited platform, the multiple antenna arrays suffer from strong mutual coupling between closely spaced array elements. In this paper, a rigorous procedure for the design of a 4-port compact planar antenna array with high port isolation is presented. The proposed design involves a decoupling network consisting of reactive elements, whose values can be obtained by the method of eigenmode analysis. Numerical results show the effectiveness of the proposed design approach in improving the port isolation of a compact four-element planar array.

Highlights

The multiple-input-multiple-output (MIMO) system has become a promising technique in existing and future generation of wireless communication systems
The high capacity offered by the MIMO system is reduced if the various signals at the receiver are correlated, where the correlation may arise from the mutual coupling between the transmitting and/or receiving antenna elements [5,6,7]
Numerical results on a four-monopole array with an antenna spacing of 0.1 wavelength show that the compact array has highly isolated driving ports and it is suitable for MIMO applications

Summary

Introduction

The multiple-input-multiple-output (MIMO) system has become a promising technique in existing and future generation of wireless communication systems. The implementation of multiple antennas in a compact terminal involves challenging design tradeoffs [3] This is due to the severe effects of mutual coupling among the closely spaced elements, which will cause significant system performance degradation [4]. A neutralization line can be inserted between two antennas to cancel the mutual coupling by introducing some current and creating an additional electromagnetic field [16] Another way to isolate highly coupled monopole antenna elements is based on the mode-decomposition method, in which a multiport network using 90∘ or 180∘ hybrid couplers is inserted between the antennas and their feeding ports [17]. Numerical results on a four-monopole array with an antenna spacing of 0.1 wavelength show that the compact array has highly isolated driving ports and it is suitable for MIMO applications

The Proposed Decoupling Network

Example and Discussion

Conclusions