Abstract: The vortex electromagnetic wave has the characteristic of carrying orbital angular momentum. Based on this feature, vortex electromagnetic waves are used as signal carrier to achieve multi-channel signal simultaneous transmission within the same frequency band, which greatly improves the system capacity and bandwidth utilization. In this paper, by utilizing the circular microstrip antenna with a semicircular slotter as an element, a kind of electromagnetic vortex generating antenna array is designed, which can work in the Ku band and K band. The array antenna is modeled and its parameters are optimized with the help of high frequency structure simulator. The analysis of the simulation results indicate that electromagnetic waves generated by the array antenna can carry the orbital angular momentum when the center frequencies are chosen as 17.1 GHz and 19.7 GHz respectively. Therefore, it is concluded that the array antenna can generate dual frequency vortex electromagnetic wave.