Modeling and Design of RFID-Controlled Binary-Reconfigurable Frequency Selective Surfaces

Radiofrequency Identification (RFID) technology is entering its third generation, extending beyond identification and sensing toward the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">control</i> of electromagnetic (EM) functions. Recent studies have demonstrated the feasibility of RFID-controlled antennas, metasurfaces, and intelligent surfaces, where standard RFID Integrated Circuits (ICs) act as wireless, battery-free controllers. Within this family, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Frequency Selective Surfaces</i> (FSSs) represent a particularly demanding case, since their narrowband resonant response must be precisely engineered under the discrete bias conditions imposed by RFID hardware. This paper presents a modeling and synthesis framework for binary-reconfigurable FSSs driven by RFID ICs. By exploiting the two programmable output voltages of commercial chips, the proposed FSS toggles between reflective and transparent states at a fixed frequency, enabling wirelessly programmable interfaces without any external supply. A semi-analytical Equivalent Circuit Model (ECM) links the target specifications—operating frequency and fractional bandwidth—to the lumped circuit parameters and, in turn, to the unit-cell geometry. The model provides a rapid and physically interpretable design tool, validated through full-wave simulations of multiple layouts showing agreement within 5% of numerical results.