Abstract: The vortex electromagnetic wave is usually generated by the circular antenna array composed of linearly polarized cells. And the feeder network becomes complex by the equiphase offset feeder. This paper theoretically demonstrates the possibility of vortex electromagnetic wave generated by the circular antenna array with circularly polarized cells. Based on the propagation characteristics of the circularly polarized wave, the electromagnetic radiation in the far field of the circular antenna array is calculated under the phase shift between the adjacent cells, by whirling the circularly polarized cells. Results prove that the vortex electromagnetic wave can be generated by the circularly polarized circular antenna array under the same phase. The simulated results also show that seven modes of orbital angular momentum, which marked as l =0, ±1, ±2,±3, can be generated by the feeder port with the same phase and adjusting the distribution degree of cells. The flexibility of feeder network could be effectively improved through this novel excitation technology of orbital angular momentum.