Dual-Mode Plasma Reflectarray/ Transmitarray Antennas

The plasma reflectarray/transmitarray antenna is a planar array, which reflects/transmits the incident fields radiating from a feed antenna. The plasma introduces a reconfigurable material for antenna applications. The proposed reflectarray/transmitarray unit cell consists of two plasma cylindrical ring tubes positioned along the top and bottom of a plasma square ground plane filled with argon gas. By controlling the ionized plasma gas density of the square ground plane, two modes of operations are obtained, reflectarray and transmitarray modes for the same unit cell. A 13 × 13 unit cell reflectarray/transmitarray antenna covering an area of 13.52×13.52 cm² is proposed. The dimensions of the unit cells are identical with different argon gas densities according to the relative phases of the reflected/transmitted wave. The reflectarray is operating at 19.39 GHz, while the transmitarray is designed for 19.75-GHz applications. The radiation characteristics of the reflectarray/transmitarray single structure have been investigated. The gain and frequency bandwidth for the new configurations are presented. An electronic beam steering plasma transmitarray antenna from -380 to +380 is introduced. A full-wave analysis using the finite integration technique is used for design and analysis of the plasma reflectarray/transmitarray antenna.