Linearly and circularly polarized radiation from metaline antennas

Four metalines, the MTLc, MTLp, MTLn, and MTLpn, are presented. It is found that the MTLp and MTLn form a circularly polarized (CP) scanning beam with change in frequency, moving from the backward direction, through the broadside direction, to the forward direction (BBF scanning). The CP polarization is right-handed for the MTLp and left-handed for the MTLn. The remaining metalines, the MTLc and MTLpn, form a linearly polarized BBF scanning beam.