The shortage of spectrum resources becomes a bottleneck in the development of wireless communication.This paper applies the technology of orbital angular momentum (OAM) to the design of array antenna and uses the microstrip patch antenna with feeding type of L probe as an element.The elements are arranged along the circumference equidistantly to present an 8-element broadband microstrip array antenna generating multi-modal OAM vortex electromagnetic waves and the adjacent elements are fed with the different phases.The operating frequency band of the antenna ranges from 1.35GHz to 1.86GHz

and meanwhile

the relative bandwidth can reach 31.8%.Experiment results show that the array antenna can generate electromagnetic waves with characteristic of multi-modal orbital angular momentum.When it is placed in the transmitting terminal of wireless communication system

the multiple signals can be transmitted on the same frequency simultaneously

which improves the transmission rate and capacity of the communication system.