A directional circularly polarized crossed‐dipole antenna with bandwidth enhancement.

Abstract: A broadband circularly polarized antenna based on the crossed‐dipole structure is designed. The antenna consists of a pair of dual‐side printed crossed dipoles, a loop phase delay line, and a parasitic patch. By modifying the configuration of the dipoles and introducing a parasitic patch, a wide axial ratio (AR) bandwidth is obtained. A defected ground plane is designed, which has a significant improvement in extending the 3‐dB AR bandwidth and enhances the gain. The proposed prototype is manufactured and measured for validation. Measured results show that the antenna achieves both −10 dB impedance bandwidth and 3‐dB AR bandwidth of 68.6% (2.3–4.7 GHz). Moreover, the average gain of the antenna is about 8 dBi within the operating band, with a floating less than 2 dB. [ABSTRACT FROM AUTHOR]