Quadrature feed wideband circularly polarized cylindrical dielectric resonator antenna

A quadrature feed circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) aiming for wideband application is proposed in this paper. The proposed CP DRA is fed with a quadrature feed network, which consists of a Wilkinson divider and a wideband 90 degrees shifter designed with a switched line structure. The feed network can provide good impedance matching, balanced power splitting, and consistent 90 degrees phase shifting over a wide bandwidth. The proposed CP DRA is designed using a cylindrical dielectric resonator with simple structure, and simulated using HFSS 12.0. The simulations indicate that the proposed antenna has good impedance and circular polarization characteristics. The prototype of the antenna is fabricated and measured. The measurements and the simulations agree well, and the measured results exhibit an impedance bandwidth (VSWR <= 2) of 43.3%, an axial ratio (AR) bandwidth (AR <= 3 dB) of 42.8%, and a 3 dB gain bandwidth of 40.8%.