Metasurface-Based Multifunctional Optically Transparent Electromagnetic Window: Switchable Transmission, Broadband Scattering Suppression, and Infrared Control

Reconfigurable optically transparent metasurfaces provide a promising platform for integrating dynamic electromagnetic (EM) regulation and optical observation. However, achieving simultaneous microwave regulation, scattering control, and infrared regulation within a single transparent architecture remains challenging. Here, we propose an optically transparent multispectral reconfigurable EM window featuring switchable dual-band microwave transmission, broadband scattering suppression, and dynamic infrared radiation regulation. By integrating tunable-resistance PIN diodes, the proposed metasurface overcomes the fixed-frequency limitation of conventional transparent EM windows, enabling switchable dual-band transmission at 4/9 GHz with continuous amplitude modulation. Furthermore, a planar bridging-inductor feeding scheme is developed to integrate the bias network with transparent meta-atoms without additional feeding lines or metallized vias. Through frequency-tailored co-design of the active transmission layer and passive scattering layer, broadband scattering suppression from 3.7 to 12.8 GHz is achieved while preserving the transmission windows. In addition, electrically controlled heating of the transparent metallic mesh enables dynamic regulation of infrared radiation characteristics. This work provides a versatile strategy for actively controlled multispectral transparent metasurfaces, offering promising applications in intelligent EM windows, adaptive communication and sensing platforms, and multispectral regulation systems.