Design of gear-type microstrip circular antenna for orbital angular momentum generation

This paper proposes a compact gear-type microstrip circular antenna (GTMCA) to generate orbital angular momentum (OAM) for wireless applications. The antenna consists of a microstrip circular loop which connected with eight rectangle patches, each rectangle patch rotating arrangement on a substrate in sequential with an equal inclination angle of 45°. The working principle of proposed antenna is analogous to that of a typical OAM-generating circular traveling-wave antenna. The analyzed and simulated results show that the gear-type microstrip circular antenna can generate OAM radio beam with topological charge l = −2, and it is a promising method for future OAM communication systems.