Switchable Reflective Metasurfaces Composed of Line Resonators for Beam Control Function in X-band Range

In this paper, switchable reflective metasurfaces (SRM) composed of open-ended line resonators are proposed. The functionality of SRM as beam control in the X-band frequency range is demonstrated through simulation and experimentation. The operational states of SRM can be changed by toggling its unit cell between ON and OFF, indicating connected and unconnected line resonators, respectively. The fundamental concept behind the unit cell involves dividing an extended line into shorter ones to alter the resonant frequency, thereby causing a shift in the phase between states. Here, the developed reflective metasurfaces are promising in multi-bit SRM design. Through out infinite array of unit cell, it is demonstrated that the phase shift between two states achieves 180 degrees at the frequency of 9.35GHz for 1-bit SRM. While for 2-bit SRM, the phase shift between consecutive states is around 90 degrees at the frequency of 10.16GHz. Based on 16 × 16 finite array of unit cell to investigate the reflection patterns carried out in two configurations, namely 4 cells/supercell and 8 cells/supercell, in the 1-bit and 2-bit SRM designs, it shows agreement between the prediction and simulation. In addition, experimental validations on the configuration of a 16×16 finite array for 1-bit and 2-bit SRM show trends in accordance with the simulated results.