A High Gain Dual Circularly Polarized Antenna for Wideband Application

a high gain dual circular polarization antenna for wideband application is designed and analyzed. The antenna consists of stacked circular discs and a complex circular feeding network which result in good circular polarization behavior over the entire bandwidth. The dimensions of the stacked circular discs are optimized to achieve good ratio and impedance bandwidth using HFSS. The feed network contains a 3dB-90 degree hybrid coupler and two 3dB-180 degree hybrid couplers, which produces an ordinal 90 degree phase -shifting between the four outputs. The simulated and measured results indicate that the bandwidth of the antenna is 300 MHz, and the reflection coefficient is less than -15dB. The circular polarization bandwidth for axial ratio less than 1.5dB reaches 14% and the isolation between the two input ports is greater than 11dB in the whole work band.