Miniaturised artificial magnetic conductor and its application in unidirectional circularly polarised slot antenna design. Issue 12 (25th May 2018)

• Record Type: Journal Article
• Authors: Li, Jianxing; Huo, Huimin; Chen, Juan; Zhu, Shitao; Shi, Hongyu; Zhang, Anxue
• Is Part Of: IET microwaves, antennas & propagation. Volume 12:Issue 12(2018)
• Page Start: 1885
• Page End: 1889
• Publication Date: 2018-05-25
• Subjects: slot antennas -- electromagnetic wave polarisation -- directive antennas -- conductors (electric) -- capacitors -- coplanar waveguides -- antenna feeds -- air gaps -- reflector antenna feeds -- UHF antennas; unidirectional circularly polarised slot antenna design -- miniaturised polarisation independent artificial magnetic conductor -- circularly polarised square slot antenna -- CPSSA -- unidirectional radiation -- coplanar waveguide -- L‐shaped strips -- diagonal corners -- circular polarisation radiation -- AMC reflector -- air gap layer -- antenna system -- return loss impedance bandwidth -- axial ratio bandwidth -- interdigital capacitors -- loss 10 dB -- frequency 2.71 GHz; Microwaves -- Periodicals; Microwave antennas -- Periodicals; Antennas (Electronics) -- Periodicals; Radio wave propagation -- Periodicals; Microwave communication systems -- Periodicals; 621.381305
• DOI: 10.1049/iet-map.2018.0108
• Languages: English
• ISSNs: 1751-8725

Abstract

Abstract : 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 .