An RF-switch-enabled low-power dual-mode reconfigurable reflective surface

This paper presents a novel reconfigurable reflective surface capable of selective magnitude control at sub-6 GHz frequencies. Each unit cell integrates a low-power single-pole double-throw (SPDT) RF switch beneath the ground plane, providing two distinct impedance states that govern the reflection coefficient of the unit cell. The proposed configuration enables dynamic switching between reflective and absorptive modes at 5.50 GHz. A full system prototype comprising an 8 × 8 unit cells was fabricated and tested, the measured results exhibit good agreement with full-wave simulations, with the 1-bit (0°-180°) reflection phase control at 5.05 GHz and reflection magnitude switching between -2.4 dB and -26 dB at 5.50 GHz under TE-polarized excitation. In addition, various geometric coding patterns were explored and implemented to further assess the surface’s capability for a thinned reconfigurability and improved power efficiency. Three sets of ring-based surface configurations were investigated in detail, demonstrating that the surface is capable of selective magnitude control at both 5.05 GHz and 5.50 GHz under these pattern configurations. Specifically, these configurations enable quantized reflection magnitude control at 5.05 GHz, with an average step size of circa 5 dB. The results confirm the surface’s flexible reconfigurability and reveal that activating only 75% of the available switches achieves performance comparable to full-surface operation, effectively reducing control complexity and overall power consumption.