Abstract: This paper proposes a high gain circularly polarized crossed dipole which is operated in VHF/UHF. Forincreasing the efficiency of the design procedure, a co-simulation method is established by combining electromagneticsimulation with circuit analysis. A feed system is designed by this method. The antenna is analyzed numerically, fabricated andtested. The experiment results explain the VSWR is less than 2 and the axial ratio is less than 3dB in a 6% bandwidth. The mainpolarization gain of the antenna reaches 7dB at the normal direction. The numerical results agree well with the experimental ones.