Janus Metasurface Breaking Polarization Symmetry: Surface-Modulated Electromagnetic Wave Radiation with Coexistent Linear and Circular Polarization

In this work, a Janus metasurface based tensor impedance holographic antenna (JHA) is proposed that simultaneously radiates linearly polarized (LP) and circularly polarized (CP) beams from a single aperture excited by a single feed. The proposed design introduces modified tensor impedance equations to significantly reduce cross-polarization at higher radiation angles. It demonstrates broadband operation bandwidth of 0.5 GHz while maintaining high circular polarization purity. The design methodology is verified using aperture field integration theory, ensuring that the impedance distribution produces the desired far-field radiation patterns. Prototypes of three variations of the holographic antenna are fabricated, validating its performance. The radiation characteristics of the proposed antenna make it an attractive choice for advanced broadband communication applications.