Theoretical analysis of the non-uniform OAM source based on an equivalent source transformation

Orbital angular momentum (OAM) has gradually become a research hotspot in radar, communication and other fields because of its phase distribution. However it encounters some problems in the real practice owing to its inherent characteristics. Recently OAM mode group has been proposed to solve these problems. In this paper, a non-uniform OAM source is used to generate the OAM mode-group (MG) directly. The radiation field is analyzed based on an equivalent source transformation. Taking the partial arc transmitting (PAT) scheme as an example, the non-uniform source is equivalenced as a group of uniform OAM sources by calculated its Fourier transform. This work provides theoretical guidance for the design of non-uniform OAM antenna in the RF domain.