Design Method for Modulated Metasurface Antennas Composed of Anisotropic Elements Based on Generalized Boundary Conditions

A novel and efficient design method for modulated metasurface antennas composed of anisotropic elements is proposed in this letter, based on generalized boundary conditions. An analytical model of surface impedance is derived with the effective surface susceptibilities of the patch layer, an equivalent circuit model of the element, and the transverse resonance technique. The analysis method of elements is then utilized to design modulated metasurface antennas with desired radiation patterns. A linearly polarized antenna prototype with a circular aperture of 180 mm in diameter is designed and measured to demonstrate the effectiveness of this approach. The prototype shows good radiation characteristics at 9.75 GHz with the measured gain of 21.77 dB and the aperture efficiency of 44.5%.