A Conformal Plasma Frequency Selective Surface with Tunable and Switching Performance

In the quest to safeguard sensitive electronic equipment, the demand for frequency-selective surfaces (FSS) that can be conformally adhered to complex surfaces while maintaining stable frequency-selective properties and transmission performance remains high. While various flexible shielding options have been introduced, achieving adequate protection against HPM requires a tunable and reconfigurable FSS capable of selectively blocking a specific frequency range during a high-power threat. Such a tunable and reconfigurable FSS serves a crucial purpose by shielding sensitive electronic equipment from high-power threats while permitting the unaffected transmission of desired frequencies. This dynamic capability to shut off a specific frequency window during a high-power threat is vital for ensuring optimal protection without compromising the functioning of the sensitive equipment. By leveraging tunability and reconfigurability, this type of FSS offers a valuable solution for protecting electronic devices in demanding environments.

This study introduces a plasma-based flexible frequency selective surface (FSS) with switchable and tunable performance. The proposed structure exhibits tunable transmission frequency response under normal power levels (OFF mode). However, when exposed to high powers (ON mode), the plasma cells ignite and effectively block the transmission, providing more than 15 dB shielding with a rapid response. The shielding performance is influenced by factors such as gas constant and pressure. The ultrathin and compact design of the proposed FSS enables high flexibility while maintaining stable electromagnetic performance, even for higher oblique incident electromagnetic waves. The fabrication procedure of a prototype will be discussed, along with experimental results illustrating the performance of both the OFF and ON modes. Furthermore, the study will investigate the power handling capabilities of the proposed design, providing insights into its ability to manage high-power scenarios effectively.