Multiplexed OAM Wave Communication With Two-OAM-Mode Antenna Systems

In order to improve the channel capacity, waves carrying orbital angular momentum (OAM) in communication systems have attracted much attention. A two-OAM-mode antenna system, which works at 2.4 GHz, is proposed in this paper. And a signal transmission experiment is performed based on a pair of the proposed antenna systems. The proposed antenna system, which has the planar structure, is composed of two patch antenna arrays, two feeding networks, and one common ground plane. Then, reflection coefficients, transmission coefficients, radiation patterns, and phase distributions of the proposed antenna system are measured, and the measurement results verify the effectiveness of this antenna system in generating two OAM modes (OAM mode 1 and OAM mode 2). The measurement results are in good agreement with the simulation results. Then, the signal transmission system is built based on a pair of the proposed antenna systems. Isolation between the OAM mode 1 transceiver channel and the OAM mode 2 transceiver channel is more than 20 dB. Video signals modulated by filter bank multicarrier are de-modulated simultaneously at the receiving terminal. It means that the two-OAM-mode antenna system has the potential to enhance the channel capacity.