Inverse Design of a Wide-Angle Wideband Programmable THz Reflectarray Through Generative Adversarial Networks

A reflectarray optimized through a Generative Adversarial Network (GAN) is demonstrated. This design focuses on the impact of the top layer on the reflection phase and utilizes the correlation between phase distribution and the direction of the reflected beam. Six programmable subcells are optimized to accommodate two incident angle waves simultaneously. Silicon substrate is exploited making the design compatible with integrated circuits. The far-field analysis indicates that for incident angles of ۱۹.۴۷۱° and ۴۱.۸۱°, as well as their vicinity, the reflectarray effectively redirects the incoming waves to reflect towards near-normal direction to its surface. This suggests a near independence of the deflection angle from the incident angle within a specific angular range, making the proposed reflectarray a planar THz beam collimator. The proposed subcells achieve a reflection phase range of ۳۴۲°. The return losses for the incident angles of ۱۹.۴۷۱° and ۴۱.۸۱° are ۱.۹ dB and ۱.۴ dB, respectively. For a finite reflectarray measuring ۱۵λ×۵λ, the pattern gain and fractional bandwidth are reported as ۱۹.۴۴ dB and ۲۴.۸% for the incident angle of ۱۹.۴۷۱°, and ۱۹.۱۷ dB and ۲۹.۹% for the incident angle of ۴۱.۸۱°. This denotes an excellent wideband behavior for the proposed single-layer pixelated reflectarray.

کلیدواژه ها:

Reflectarray ، Unitcell ، Subcell ، Deflection ، Generative Adversarial Network