A Novel Design of Wideband Circular Polarization Antenna Array with High Gain Characteristic

A broadband of circularly polarized (CP) patch antenna fed by L-probes has been presented in this paper. In order to improve axial ratio bandwidth, wideband 90° hybrids with two L-probe feeds are used as feeding netwok, and cones act as radiator instead of common circular patch. A total of 6 array elements are used in a 2 × 3 configuration to achieve a maximum gain target of 14 dBi. However, it will enlarge the overall size of the antenna. The feeding network is located on the lower side of the substrate for compacting the size. The measured results agree well with simulations, indicating that the antenna array possesses an impedance (VSWR < 2) bandwidth of 42% and axial ratio (AR < 3 dB) bandwidth of 47.6%. In addition, the 8-dB gain bandwidth and peak gain are 55% and 14 dBi, respectively.