Decoupling of Two Closely‐Spaced Planar Monopole Antennas Using Two Novel Printed‐Circuit Structures

• Published in: Microwave and optical technology letters Vol. 60; no. 12; pp. 2954 - 2963
• Main Authors: Isaac, Ayman A., Al‐Rizzo, Hussain, Yahya, Samer, Al‐Wahhamy, Abbas, Abushamleh, Said
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.12.2018; Wiley Subscription Services, Inc
• Subjects: 4G/5G LTE/LTE‐A; Correlation coefficients; Decoupling; Ground plane; MIMO; Monopole antennas; Monopoles; Mutual Coupling; Planar Monopole; Substrates; WiMAX; Wi‐Fi
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.31405

A new approach is presented in this paper to reduce mutual coupling between two closely‐spaced planar monopole antennas. The approach employs either two parallel metallic strips or a single strip with a meander‐shaped slotted pattern symmetrically placed between the two antennas with their edges being separated by 4 mm and 8 mm, respectively. The novel aspect of our approach is that the decoupling structures are not only confined in the space shared by the two planar monopole edges but are rather extended above the partial ground plane on one end and to the edge of the substrate on the other end. The design provided measured −10 dB impedance and − 20 dB decoupling bandwidths extending from 1.65 GHz to 4 GHz, and 1.43 GHz to 3.7 GHz, respectively, and the measured realized gains at 2.45 GHz are 3.81 dBi and 2.14 dBi, respectively. The proposed arrays offer excellent MIMO performance in terms of envelope correlation coefficient and link efficiency in realistic MIMO propagation environments through the decoupled frequency regimes.