Broadband circularly‐polarised chifre‐shaped monopole antenna with asymmetric feed

Abstract

A broadband circularly‐polarised monopole antenna is proposed. The broadband property of the antenna is basically achieved not only by the chifre‐shaped monopole radiator, but also its asymmetric feed. The circular‐polarisation characteristics are greatly enhanced by adjusting the location of the monopole microstrip‐feed. The antenna delivers good performance on impedance matching and circular polarisation. The measured results demonstrate that the impedance bandwidth is 72% and the 3‐dB axial‐ratio bandwidth reaches 41.6% with a central frequency of 2.5 GHz.