Circularly polarized antenna with two edge-coupled open-loops

Abstract

A wide-band circularly polarized antenna with two rectangular open-loops coupled by a printed monopole is presented. The two open-loops are placed side by side and are coplanar with the ground plane of the monopole. The gap of one open-loop is on the top-edge, while the gap of another open-loop is on the bottom-edge. The return-loss and the axial-ratio bandwidths of the antenna are tuned by varying the position and the size of the two gaps. For an optimized antenna without a back-up metallic reflector, return-loss bandwidth of 68.7% (2.2–4.5 GHz) and axial-ratio bandwidth of 53% (2.2–3.8 GHz) can be achieved. The axial-ratio bandwidth of the antenna with a back-up reflector is 38%.

Keywords:

• open-loop
• monopole antenna
• circular polarization
• asymmetric