Wideband Endfire Circularly Polarized Antenna using Magnetoelectric Dipole

A wideband endfire circularly polarized (CP) antenna using magnetoelectric dipole (magnetic and electric dipoles) is proposed and investigated. The vertically polarized magnetic dipole is formed using a three-sided closed cavity and opened at one side. A feed line connects a vertically polarized magnetic dipole and a horizontally polarized electric dipole to create a CP wave in the endfire direction. A two-layer profile system is used to increase the impedance bandwidth (IBW) of the CP antenna. To validate the simulation results, measurements of the antenna parameters of the proposed structure are performed. The proposed endfire CP antenna provides (5.56-6.3 GHz) 12.47% IBW and (5.59-6.11 GHz) 8.88% axial ratio bandwidth (ARBW). The proposed endfire CP antenna has a measured maximum gain of 5.47 dBic and an endfire polarization purity of 18 dB at the centre frequency. The complete dimension of this antenna is 0.907 lambda(L) x 0.498 lambda(L) x 0.064 lambda(L), where lambda(L) is the lowest frequency of the IBW.