Theoretical design considerations for dual circularly-polarized broadside beam metasurface antenna

This paper describes the operating principle of a modulated metasurface antenna (MoMetA) capable to provide both Right-hand and Left-hand circularly polarized boresight radiation at Ku-band. This antenna is based on the interaction between two cylindrical-wavefront TE and TM surface wave (SW) modes with perfect polarization and phase balances. Feeding system requirements and characterization of the surface impedance properties to guarantee balance conditions as well as desired radiation are detailed.