Tunable spatial power splitter using single layer cylindrical plasma discharges

This work presents a novel single-layer, reconfigurable spatial power splitter based on plasma discharges. Each unit cell features two adjacent core–shell cylinders, composed of a tunable plasma core surrounded by a high-permittivity dielectric shell. The plasma core is modeled using a free-electron plasma permittivity with variable plasma frequency. Numerical simulation demonstrates that the power-splitting ratio can be continuously varied between 30% and 70% by independently controlling the plasma frequencies of the two cylinders. This reconfigurability enables precise manipulation of the transmitted power distribution while limiting the total reflected, absorbed, and undesired diffraction power to less than 10% of the incident energy, corresponding to an overall efficiency exceeding 90%.