Enhanced dual‐band circularly polarised broadband antenna by using the parasitic patch

Abstract

For reference antenna without parasitic patch, it covers the impedance operations from 1.72 to 4.73 GHz and 5.38 to 6.62 GHz with | S 11 |≤-10 dB, and has dual sense circular polarisation (CP) between 3.4 and 3.8 GHz (11.1%), between5.5 and 5.63 GHz (2.3%), respectively. In this study, to further improve the performance, an enhanced coplanar waveguide fed dual CP broad bandwidth antenna is proposed by using the C-shaped parasitic patch. It covers the impedance operations from 1.72 to 6.6 GHz with | S 11 |≤-10 dB, the 3-dB axial ratio between 2.92 and 4.04 GHz (32.2%) for left-hand CP as well as that between 5.42 and 5.63 GHz (3.8%) for right-hand CP are achieved. Compared with reference antenna, it is obviously that the proposed antenna achieves a remarkably enhanced dual CP with wider resonant bandwidth. Furthermore, the measured results and simulated results are agreement well with each other.