Design and fabrication of a multispectral transparent architecture for microwave–terahertz selective absorption

As next-generation wireless communications, particularly 6G, expand across multiple frequency bands, selective electromagnetic absorbers (EMAs) are needed to suppress interference without attenuating non-target signals. Integrating microwave–THz absorption selectivity with optical transparency and conformability remains challenging. Here, we experimentally demonstrate a transparent and conformable EMA comprising separately designed microwave and THz functional blocks.The proposed EMA experimentally achieves frequency-selective electromagnetic absorption with reflection losses of −13.4 dB, −17.4 dB, −24.4 dB, and −13.5 dB at 2.43 GHz (Bluetooth), 5.19 GHz and 6.60 GHz (5G/6G Wi-Fi), and 0.34 THz (terahertz source), respectively. Layer-resolved power-loss analysis, power loss density distribution and transmission-line models reveal that the microwave response is predominantly governed by the microwave block, while the THz block determines the principal features of the THz absorption spectrum. Moreover, in the integrated EMA, replacing the microwave-block substrate leaves the microwave absorption peaks largely unchanged, whereas modifying the THz-block cover layer changes the THz absorption from broadband to narrowband. These results demonstrate a strategy for integrating selective microwave–THz absorption, optical transparency, and conformability without stringent interlayer alignment.