Design Method of Broadband Metasurfaces for Generating a Two-dimensional Gaussian Beam from a Normal Incident Plane Wave with the Same Amplitude Distribution

The design method of broadband metasurfaces for generating a two-dimensional (2-D) Gaussian beam from a normal incident plane wave with the same amplitude distribution is presented based on the one-dimensional transmission-line model. The formula of the characteristic impedance of the model is derived according to the concept and an electromagnetic metasurface is designed by using the model with the parameters determined from the formula. Circuit simulations are carried out to confirm the validity of the design with the model. The results show that the designed metasurface generates a 2-D Gaussian beam from an incident plane wave and also has the broadband characteristics.