Antenna with circular polarization composed of bent crossed dipoles in a cylindrical cavity

The paper presents cavity backed printed antenna with circular polarization (CBACP). The antenna radiating elements are two crossed double bent dipoles that are printed on the dielectric substrate and have complex conjugated impedances. In order to diminish environmental influences the antenna is placed in the metallic cylindrical cavity. By using double bent dipoles the overall antenna dimensions are significantly reduced. CBACP is simulated and realized for operation around 5.9 GHz. Simulated and measured results show good agreement. Furthermore, investigation of cavity parameters and their effect on antenna characteristics has been carried out in order to achieve (a) minimal axial ratio, (b) maximal gain and aperture efficiency and (c) broader axial ratio bandwidth (AR<;3 dB).