A Circularly Polarized C-Band OAM Antenna Array

A circularly polarized (CP) C-band antenna array for OAM's generation is proposed in this paper. The center frequency of the circularly polarized antenna element is 6GHz, and S
₁₁
is lower than -10dB in the operating frequency range of 5~8.5GHz. The axial ratio is lower than 3dB in the same bandwidth. 32 circularly polarized antenna elements are placed radially and uniformly on the same circumference. With the appropriate initial phase shift to every antenna, the characteristic of OAM waves can observed from both X-/Y-component of electric fields, and their OAM mode purity are all higher than 0.96.