A Broadband Circularly Polarized Antenna Array Based on Sequential Rotation Feeding

In this article, a circularly polarized antenna array using sequential rotation feeding technology is designed. The radiation unit of the antenna is based on cutting off two diagonal square patche, and is formed by digging two orthogonal cross slots at the center of the square patch and loading four semi-circular branches around the square patch. To further expand the bandwidth and improve antenna gain, parasitic patches are added above the antenna. In order to broaden the 3dB axial ratio bandwidth, using sequential rotation feeding technology to form a 2×2 array. The S parameter of the array is below -10dB at 16.5GHz to 19.1GHz, and its 3dB axial ratio bandwidth is 33.5% (14.0GHz to 19.7GHz).Within the operating frequency range of the antenna, the axial ratio of the antenna is below 3dB, and the gain is stable at 7.2dBi. The antenna proposed in this report can meet the demand for circularly polarized antenna arrays typically used in aviation and aerospace, radar, and communication systems.