A broadband circularly polarized antenna array for beamforming applications in X-band

This paper presents a 4-element bidirectional antenna array with broadband circular polarization (CP) property in X-band for beamforming applications. The antenna element achieved CP characteristics by the asymmetrical Y-shaped feeding line with 10-dB return loss bandwidth of 31.4%, in which the AR is less than 2 dB. The simulated array achieves an impedance bandwidth antenna of 39.3%, in which the AR is less than 3 dB; the simulated radiation pattern shows a near symmetry bidirectional radiation with the peak gain of 11.6 dBi.