Novel Circularly Polarized Printed Crossed Dipole Array with Broad Axial Ratio Bandwidth

The novel printed crossed 2×2 dipole array is proposed for broad axial ratio (AR) bandwidth. The broad bandwidth of axial ratio is due to a parasitic dipole crossing over the original dipole that is driven by a semi-rigid coaxial feed with the characteristic impedance of 75Ω. The crossed dipole, a unit element of the dipole array proposed in this paper, can produce a broad circularly polarized (CP) operation by itself because of the sequentially rotated configuration. The measured 3 dB AR bandwidth is 39.2% and the gain is 13 dBi at the CP center frequency of 2.32 GHz. Details of the proposed dipole array design are described and both the simulation and the experimental results are presented and discussed.