Mutual coupling reduction and gain enhancement in patch array antenna using a planar compact electromagnetic bandgap structure

• Published in: IET microwaves, antennas & propagation antennas & propagation, 2017-09, Vol.11 (12), p.1719-1725
• Main Authors: Mohamadzade, Bahare, Afsahi, Majid
• Format: Article
• Language: English
• Subjects: antenna radiation patterns; EBG; frequency 5.59 GHz; gain enhancement; microstrip antenna array; microstrip antenna arrays; minimal inter‐element spacing; mutual coupling; mutual coupling reduction; patch array antenna; photonic band gap; planar compact electromagnetic bandgap structure; Research Article; unit cell arrangements; wireless local area network band
• ISSN: 1751-8725; 1751-8733; 1751-8733
• DOI: 10.1049/iet-map.2017.0080

This research work presents a planar compact electromagnetic bandgap (EBG) structure with the potential to reduce the mutual coupling between the elements of a microstrip antenna array. The proposed structure is investigated at 5.59 GHz, which is the centre frequency of the wireless local area network band. To achieve the highest radiation performance for microstrip antenna arrays, with minimal inter-element spacing and mutual coupling, different unit cell arrangements were considered along with two adjacent patch elements. The simulations and measurement results for the proposed arrangements indicate that the mutual coupling tends to diminish significantly. For instance, when adjacent patches are spaced by 0.4λ, the mutual coupling improves by ∼25 dB. For the particular spacing of 0.4λ, it is favourably observed that the proposed EBG cells can also improve the antenna gain by ∼2.5 dB. Such improvements can be attributed to the compactness of the cells (∼λ/8 × λ/10) and their remarkable ability to suppress the surface waves.