Reconfigurable orbital angular momentum generator with vortex beam direction and mode adjustment

The mode detection and transmission of the orbital angular momentum vortex wave are studied intensively on the basis of the proposed mechanically reconfigurable circular array antenna which consists of broadband and circular polarization single-arm spiral antenna (SASA) allowing self-rotation around the axis to produce a relative change in phase of the radiated field in space. Furthermore, the main beam direction of the orbital angular momentum(OAM) vortex wave can be flexibly controlled by adjusting the rotation angle of each array element around its axis according to the phase characteristics of the SASA. The proposed design can realize the vortex beam direction and OAM mode reconfigurability. In addition, the left-hand circular polarization or right-hand circular polarization vortex wave can be adjusted by changing the rotation angle of the SASA. The prototype of the circular array is proposed, fabricated, and measured to validate the effectiveness and correctness of the proposed method.