Abstract
In this paper, a multilayer uniform circular array (UCA) with circularly polarized (CP) patch elements is proposed to generates dual-mode orbital angular momentum (OAM) beams. To eliminate the dependency of phase excitation on feed length, the proposed UCA is designed with a CP elliptical patch as an array of elements that are geometrically rotated to obtain the desired phase excitation. By providing the input excitation of the feed network strategically, the resultant CP radiating patches can be excited for generating OAM modes l = +1 or +2 respectively. The UCA’s performance is determined in terms of S11, radiation pattern, and E-field phase distribution. According to the simulation results, the UCA produces a dual-mode OAM beam at 5.9 GHz. Therefore, the proposed UCA could be advantageous for wireless communication systems.