Design Method of Broadband Flat Metasurface Lenses by Using an One-Dimensional Distributed Transmission-Line Model

We propose a design method for broadband flat metasurface lenses by using an one-dimensional distributed transmission-line model. The design formula of the line length is shown and how to determine the characteristic impedance is stated. Circuit simulations are carried out to confirm the validity of the design method and broadband operations of a designed flat metasurface lens are demonstrated.