Open AccessWideband circularly polarised antenna based on interelement mutual coupling effect
Author(s) -
Zhou Peng,
Huang QiuLin,
Yang Lin,
Li Xi,
Shi XiaoWei
Publication year - 2020
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2020.0571
Subject(s) - wideband , ground plane , standing wave ratio , dipole antenna , physics , bandwidth (computing) , optics , antenna (radio) , electrical engineering , engineering , microstrip antenna , telecommunications
This study presents a circularly polarised (CP) antenna with a wideband characteristic, which is caused by the interelement mutual coupling effect. The proposed antenna consists of a dipole array with four elements in centre symmetry and a wideband feed network. In order to extend the lowest working frequency, a strong mutual coupling effect is introduced to the adjacent co‐polarisation elements. What's more, the introduced effects of capacitive coupling reactance counteract the effects of the element's inductively reactive ground plane. Then, a small, tightly coupled array is formed that possesses wide impedance bandwidth and orthogonal polarisation component. A wideband feed network, including Wilkinson power dividers, phase shifters, and impedance converters, is designed to provide amplitudes and phases excitation that circular polarisation antenna required. Finally, a prototype is fabricated and tested. Measured results show a VSWR<2 impedance bandwidth of 102.7% (2.09–6.5 GHz) and a 3‐dB axial ratio bandwidth of 94.2% (2.25–6.25 GHz). Besides, a relatively stable gain is realised across the operating band.