Performance comparison of wideband circularly-polarized antenna arrays comparison of microstrip-line- and metamaterial-line-based feed networks

This paper presents performance comparison of two circularly-polarized antenna arrays where H-shaped antenna elements are used and arranged in fashion of planar sequential rotation in near-field region. The two identical arrays are fed by using the state-of-the-art metamaterial lines and conventional microstrip-lines, respectively. Through the comparison, it is shown that the array excited by metamaterial-line-based feed network can achieve a wider axial-ratio (3-dB) bandwidth than the conventional counterpart, 89.3% versus 54.8%, while similar gain performances between arrays are observed.