All‐Fabric Flexible Frequency‐Selective‐Rasorber Based on Cutting‐Transfer Patterning Method

Frequency‐selective rasorber (FSR) can realize a passband between two adjacent absorption bands, which is essential in many electromagnetic scenarios such as antennas and cloaking technologies. However, the current printed circuit board (PCB)–based FSR has shortcomings such as being heavy, rigid, and complex structure (too many lumped elements), making it a long distance from practical military and civil applications. Here, a novel FSR comprised of carbon cloth/ copper cloth/ fabric hybrid structure is proposed to realize the function of frequency selective absorption for the application of indoor electromagnetic protection. Several sub‐subjects are studied, including the structure design of rasorber without lumped elements, the carbon cloth‐based planner resistive material, and the fabrication method of large area non‐contact patterns. Measured results show that a transmission window is achieved between two absorption bands with a transmission rate higher than 86%. Under the circumstances of similar electromagnetic properties, the sample has the unique features of simple structure, large area, high flexibility, and light‐weight compared with commonly used PCB technology, which largely improve the usability of FSR in practical civil or military applications. All‐fabric‐based flexible‐frequency‐selective‐rasorber (FSR) is presented in this work. Several sub‐subjects are studied, including the fabrication method of large area non‐contact patterns on flexible substrates, the structure design of rasorber without lumped elements, and the carbon cloth‐based planner resistive material. The method proposed in this work improves the usability of FSR in practical civil or military applications.