Beam Steering using Space-Time Modulated Coding Metasurface Based on Reconfigurable Plasma Ionization

Abstract

This paper explores the use of space-time coding in beam steering, using 1-bit, 2-bit, and 3-bit reconfigurable coded meta-surfaces. By periodically changing the code arrangement in the time domain, a metasurface with code order in space and time is achieved. Selected codes are used to steer the beam in different directions for radar sensing systems applications. The phase of the harmonic signal is changed by controlling the position of different bits in each code sequence. The construction of 8×8 unit-cell elements (120×120×3.2 mm3) involves the use of a grounded dielectric container filled with inert-argon gas. The metasurface logic-state is controlled via the ionization degree of inert-gas with time-switching controlling the harmonic frequencies. Different time-switching sequences are investigated for beam steering. The proposed coding metasurface is analysed using CST Microwave Studio and the results are compared with the analytical solution using MATLAB.