The design method of the ring-focus antenna forming ring beam

In the systems such as satellite communication and mobile communication, the antenna with ring beam is needed. Based on ring-focus antennas, the antennas with ring beam with any departure angle can be realized. The design method of the antenna is provided and the formulae are derived strictly, then the real examples are computed, so the validity of the design method is testified. The antenna with ring beam has the advantages such as high gain and accurate beam direction.