A Mimo Antenna Decoupling Network Composed of Inverters and Coupled Split Ring Resonators

Abstract

Abstract-A decoupling network for a pair of strongly coupled MIMO antennas is presented. The decoupling network is composed of two inverters and two split ring resonators (SRRs) that are also coupled. By properly transforming the mutual admittance of the original coupled antennas and properly designing the coupling between the two SRRs, more than 20 dB isolation between the two antennas can be achieved while their respective matching performances remain good. To validate the concept, a microstrip decoupling network is designed and implemented for a pair of wideband printed monopole antenna elements. Measurement results have demonstrated that nearly 10% bandwidth for 20 dB isolation can be achieved. Measured radiation patterns have demonstrated a significant reduction of the correlation coefficient, which makes the proposed technique a promising candidate for both current and future generations of MIMO-enabled mobile terminals.

RETRACTED: Design of Metamaterial Loaded Wideband Sub-6GHz 2×1 MIMO Antenna with Enhanced Isolation Using Characteristic Mode Analysis

“…Implementation of electromagnetic bandgap (EBG) structures in [15][16][17] provide a signi cant reduction in mutual coupling as well. Implementing split ring-resonators (SRR's) [18][19][20] and complementary split-ring resonators (CSRR) is also used by authors in [21][22][23] to improve isolation levels. Metamaterials such as epsilon negative (ENG) [24], mu-negative(MNG) [25], and near-zero mu (NZM) [26] materials are implemented to provide a change in surface current distribution resulting in improved isolation levels.…”

“…In contrast, the proposed design in [20] provides isolation enhancement only in the millimeter-wave (mmWave) range. The structures proposed in [21][22][23][24][25][26] exhibit good isolation levels (S 12 >-20dB) at the cost of compactness. The CMA-based designs proposed in [27][28][29][30] provide improved isolation with a compact structure but do not provide a wide bandwidth.…”

MIMO Antennas: Design Approaches, Techniques and Applications

“…MIMO designs must display wideband features to meet the demands of increased spectral efficiency, provided that the reciprocal coupling between the radiating components is kept to a minimum [ 17 , 18 , 19 ]. The decoupling network using two inverters and two connected split-ring resonators (SRRs) in [ 20 ] provides excellent isolation between the ports.…”

Design and Analysis of a Dual-Band Semitransparent MIMO Antenna for Automotive Applications

“…Te coupling can be reduced by increasing the distance between the antenna elements, but this increases the size of the MIMO antenna [5]. Te decoupling structures [6,7], frequency selective surfaces/metamaterials [8,9], defected ground plane [10,11], and neutralization lines [12,13] can improve isolation, but they complicate antenna design. Another method for increasing isolation is to position the antenna elements orthogonally to each other.…”