Planar bent-cross-shaped metaline antenna for circularly polarized reconfigurable radiation

A planar antenna consisting of four bent arms on a thin dielectric substrate is investigated. The arms are located symmetrically with respect to the coordinate origin, and each is made of a circularly polarized (CP) metaline that shows a negative propagation phase constant at the design frequency (2.45 GHz). The antenna height is extremely small: approximately 0.03 wavelength. By changing the feed point, the antenna can be made to radiate a CP wave in each of the four orthogonal directions of the azimuth plane. The VSWR is less than 2. Mutual coupling between the four arms is small (less than -30 dB).