Generation of OAM Radio Waves Using Circular Vivaldi Antenna Array

Abstract EN

This paper gives a feasible and simple solution of generating OAM-carrying radio beams.

Eight Vivaldi antenna elements connect sequentially and fold into a hollow cylinder.

The circular Vivaldi antenna array is fed with unit amplitude but with a successive phase difference from element to element.

By changing the phase difference at the steps of 0, ±45°, ±90°, ±135°, and 180°, the OAM radio beam can be generated with mode numbers 0, ±1, ±2, ±3, and 4.

Simulations show that the OAM states of ±2 and ±3 are the same as the traditional states, while the OAM states of 0, ±1, and 4 differ at the boresight.

This phenomenon can be explained by the radiation pattern difference between Vivaldi antenna and tripole antenna.

A solution of distinguishing OAM states is also proposed.

The mode number of OAM can be distinguished with only 2 receivers.