Open AccessMiniaturised artificial magnetic conductor and its application in unidirectional circularly polarised slot antenna design
Author(s) -
Li Jianxing,
Huo Huimin,
Chen Juan,
Zhu Shitao,
Shi Hongyu,
Zhang Anxue
Publication year - 2018
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.2018.0108
Subject(s) - conductor , optics , return loss , slot antenna , materials science , radiation pattern , axial ratio , optoelectronics , circular polarization , antenna (radio) , physics , electrical engineering , microstrip , engineering , composite material
A polarisation independent artificial magnetic conductor (AMC) miniaturised using interdigital capacitors is investigated. Its performance is analysed and compared with two other previously reported AMCs. Then, a circularly polarised square slot antenna (CPSSA) utilising the proposed AMC as a reflector is implemented, which achieves unidirectional radiation and low profile simultaneously. The CPSSA is fed by a coplanar waveguide and loaded by two L‐shaped strips placed around two diagonal corners, providing the required perturbation for circular polarisation radiation. In between the slot antenna and the AMC reflector is an air gap layer. The performance comparison of the whole antenna system employing different reflectors (three AMCs and one perfect electric conductor (PEC)) proves the advantage of the proposed AMC. As for the fabricated antenna prototype, the measured 10 dB return loss impedance bandwidth and 3 dB axial ratio bandwidth are 15.9 and 4.1%, respectively, corresponding to the centre frequency of 2.71 GHz. In addition, an almost constant gain of around 5.5 dBic has been obtained across the circular polarisation bandwidth within an overall antenna volume of 0.54 λ 0 × 0.54 λ 0 × 0.08 λ 0 .