A Circularly Polarized Broadband Sequential Array Antenna with Diamond-Shaped Artificial Ground Structure

This letter describes a wideband circularly polarized (CP) array antenna with 2 × alignment of sequentially rotated CP patch elements. Each element has diamond-shaped artificial ground structure (DAGS), which extend the 3-dB axial ratio (AR) bandwidth antenna, and elements in are fed relative phases 0°, 90°, 180° 270°. The main purpose this work is to show potential AR by combination DAGS sequential rotation technique considering effect coupling neighboring proposed achieves an overlapped 74.9% (4.30 GHz-9.45 GHz) -10-dB |S11|, gain characteristics. Also, 54.65% at 5.0 GHz-8.76 GHz. Furthermore, cross-polarization sufficiently suppressed beam 14 dBic. As result, it shown that can be applied technology low coupling, broadened.