Design of microstrip antenna array with electromagnetic radiation carrying orbital angular momentum (OAM) at C-band

This paper describes the design of an array antenna which can generate radio waves carrying orbital angular momentum (OAM) at 6 GHz. We consider the microstrip antenna with coaxial feed as the element to compose the circular antenna array which is excited with unit amplitude but with phase delay from element to element. According to the simulation and optimization with high frequency structure simulator(HFSS), we get different patterns of OAM modes depending on the different phase delay, and obtain the vortex electromagnetic wave carrying orbital angular momentum.