Broadband circularly polarized square slot antenna with a G‐shaped feedline

Abstract

Abstract This article presents the design of a compact circularly polarized square slot antenna fed by a G‐shaped strip feedline. The 3 dB axial ratio (AR) band can be achieved by modifying the feedline by simply extending it with an L‐shaped monopole and an inverted C‐shaped monopole. In simple terms, the extended part resembles a G‐shaped patch when viewed from the top. To extend the AR bandwidth achieved by the G‐patch, perturbations in the form of a U‐strip and an L‐shaped slot were introduced in the wide slot and ground plane, respectively. Measured results showed a wide 3 dB axial ratio bandwidth of 37.1% (4.5–6.55 GHz) and an impedance bandwidth of 70.1% (3.32–6.95 GHz). The proposed antenna is suitable for wideband circular polarization applications in the IEEE C‐band.