Vanadium oxide-based 16 x 16 reflectarray or FSS, reflect-transmitarray and FSS-based Cross-polarized wave absorber for future 6G applications

In this paper, a novel unit cell-based array is designed and analyzed using a VO2-based intelligent ground plane. The proposed array can be used as reflectarray or frequency selective surface (FSS), FSS based cross-polarized wave absorber, and reflective-transmittive surface. The intelligent ground plane is made up of a cross-shaped slot, and it is filled with a thin vanadium dioxide (VO2) layer. The conductivity of the VO2 material is temperature-sensitive and it is changed due to the applied external DC biasing. The tunability of VO2 conductivity introduces the quad-function performance characteristics in a single array at 1-2 THz band. The first application of reflectarray is obtained by high DC (V-1 Volt) biasing, while the other three applications are achieved by low voltage V-2 (V-2 < V-1). A polarization rotating unit cell (PRUC) is designed to enhance the bandwidth and to obtain a wide 180 degrees phase shift. This novel compact array saves the cost and area for THz applications. The array consists of 16 x 16 elements which is illuminated by a normal incidence of pyramidal horn antenna. The total volume of the array is 1600 x 1600 x 2100 mu m(3). The performance characteristics of the individual unit cell and array with and without intelligent ground plane are simulated in CST Microwave Studio.