Circularly polarized grid array antenna composed of open-loop elements for beam scanning

This paper proposes a novel GAA that radiates a CP beam whose direction varies with frequency. The proposed GAA is composed of open-loop elements, instead of spiral elements; the proposed GAA has a two-layer structure leading to easy fabrication, unlike the spiral GAA. The radiation characteristics, including the beam direction, axial ratio, and radiation pattern, are analyzed and discussed.