Impedance Network-Based Design of a Metasurface for Polarization-Controlled Reflection and Transmission

Designing metasurfaces capable of controlling both reflection and transmission under dual-polarization states at the same frequency remains a major challenge, primarily due to the reliance on computationally intensive full-wave simulations. Furthermore, a comprehensive theoretical design framework for such metasurfaces is still lacking. This paper presents an efficient design methodology for polarization-controlled metasurfaces that manipulate both transmitted and reflected waves. The approach begins by developing an impedance network model for the unit cell, enabling accurate prediction of reflection and transmission responses under dual-polarization states. The model’s accuracy is validated through the analysis of a unit cell with various loading conditions, including PIN diodes, capacitors, short circuits, and open circuits, demonstrating close agreement with full-wave simulations. Using this model, a unit cell is designed to achieve 2-bit phase coding in reflection for one polarization and 1-bit phase coding in transmission for the orthogonal polarization, both at the same frequency. The Generalized Snell’s law is then extended to determine the spatial arrangement of unit cells for a demonstration scenario, which achieves far-field beam steering in reflection and near-field focusing in transmission. Theoretical, numerical, and experimental results verify the effectiveness of the proposed design approach.