Ramin Dehdasht-Heydari - Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran.
Laleh Amiri - Department of Telecommunication, College of Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran
Zahra Hossein-Khani - Department of Telecommunication, College of Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran
Hanieh Shahveisi - Department of Telecommunication, College of Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran

This paper presents a circular polarization quad ridged horn antenna based on a VSWR≤2.55 which its bandwidth covers X and Ku bands most suitable for electromagnetic compatibility and radar applications. A new coaxial line to quadruple-ridged waveguide transition accompany to a new technique for tapering the flared section of the horn have been introduced to improve the return loss and impedance matching, respectively. Results of simulation for VSWR, isolation, axial ratio and radiation pattern of the designed circularly polarized horn antenna are validated by using two commercial CST and HFSS packages.

component; Axial ratio (AR), circular polarization (CP), quad ridged horn antenna, quadruple-ridged waveguide