Circular polarized small antenna based metamaterial coplanar-waveguide (CPW) transmission line

In this paper, a circular polarized small antenna is proposed by way of a metamaterial coplarnar-waveguide (CPW) transmission line (TL). The zeroth-order resonance of the metamaterial TL is introduced to minimize the antenna size. Its bandwidth is expanded due to the design flexibility of the CPW configuration. The circular polarization (CP) is achieved by the L-shaped stub whose current distribution is orthogonal to the original current distribution from the zeroth-order resonance. Details of the design procedure are described. The proposed antenna´s performance is demonstrated by numerical and experimental results.