Circularly polarized slot array antenna based on substrate integrated waveguide

This paper proposed a new approach to implement circularly polarized slot array antenna based on substrate integrated waveguide (SIW), which could be a potential technique in many fields, such as satellite communication etc. The design mainly includes a compact directional coupler, alternating phase power divider and a pair of symmetrical +45deg/-45deg linearly polarized slot array antennas. The slot array is simulated and optimized with full-wave electromagnetic (EM) software and then fabricated with a normal low cost printed circuit board (PCB) process. The measured results show good agreement with simulations. The antenna shows a good performance with the 3 dB axial ratio bandwidth of 9% and the gain of 17.13 dB at 11 GHz.