Mutual-Coupling Isolation Using Embedded Metamaterial EM Bandgap Decoupling Slab for Densely Packed Array Antennas

Alibakhshikenari, Mohammad; Khalily, Mohsen; Virdee, Bal S.; Hwang See, Chan; Abd-Alhameed, Raed A.; Limiti, Ernesto

Abstract

This article presents a unique technique to enhance isolation between transmit/receive radiating elements in densely packed array antenna by embedding a metamaterial (MTM) electromagnetic bandgap (EMBG) structure in the space between the radiating elements to suppress surface currents that would otherwise contribute towards mutual coupling between the array elements. The proposed MTM-EMBG structure is a cross-shaped microstrip transmission line on which are imprinted two outward facing E-shaped slits. Unlike other MTM structures there is no short-circuit grounding using via-holes. With this approach, the maximum measured mutual coupling achieved is -60 dB @ 9.18 GHz between the transmit patches (#1 & #2) and receive patches (#3 & #4) in a four-element array antenna. Across the antenna’s measured operating frequency range of 9.12 to 9.96 GHz, the minimum measured isolation between each element of the array is 34.2 dB @ 9.48 GHz, and there is no degradation in radiation patterns. The average measured isolation over this frequency range is 47 dB. The results presented confirm the proposed technique is suitable in applications such as synthetic aperture radar (SAR) and multiple-input multiple-output (MIMO) systems.

• Journal Article Type: Article
• Acceptance Date: Mar 26, 2019
• Online Publication Date: Apr 9, 2019
• Publication Date: Apr 9, 2019
• Deposit Date: Apr 1, 2019
• Publicly Available Date: Apr 2, 2019
• Journal: IEEE Access
• Electronic ISSN: 2169-3536
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Pages: 51827-51840
• DOI: https://doi.org/10.1109/ACCESS.2019.2909950
• Keywords: Metamaterial, electromagnetic bandgap, array antennas, decoupling slab, mutual coupling, synthetic aperture radar, multiple-input multiple-output.
• Public URL: http://researchrepository.napier.ac.uk/Output/1697993
• Contract Date: Apr 1, 2019