The radial line concentric slot array antenna

The circular polarization is useful for the telecommunication, the sensor, the broadcast, and so on. One of the antenna is the radial line waveguide0slot array antennas. This structure are made from two plate for radiating waveguide. In this research, based on the theoretical calculation of the hybrid feed structure composed of the circular waveguide and coaxial feed and ring slot, and patch structure and the radial line. And we simulates the hybrid feed structure using the electromagnetic field analysis simulator based on the finite element method. The rotation mode feeding structure realized the concentric array radial line slot antenna for the bore sight beam. The axial ratio is 0.037dB. When the slot pairs are increased from 4pair to 16pair, the circular polarization axial ratio is improved.