耦合对环形相控阵生成涡旋电磁波的影响

Uniform circular array (UCA) can generate vortex wave with orbital angular momentum(OAM) in microwave band, this paper studies the effects of the coupling among the units on the OAM modes. The effects are evaluated by analysis and numerical computation based on momentum method (MoM). The results show that, if the coupling among units is rotational symmetry, then the coupling will not affect the generation of the OAM-carrying vortex wave. But if the coupling among units is not rotational symmetry, then the coupling will affect it. The effects is influenced by the mode number, the radius of the UCA, and the azimuth location of the field. Based on the characteristics used in the paper, even if the distance between the neighboring units is larger than two wavelengths, the mode number will be changed by more than 14%. It is significant for UCA design for vortex wave generation.