A Plasma-Based Frequency-Selective Limiting Reflectarray

High-power microwaves can disrupt communication frequencies and cause extensive damage to electronic equipment. Therefore, it is crucial to shield sensitive equipment from incoming high-power waves. Frequency-selective surfaces (FSS) are planar periodic arrays that exhibit selective filtering responses. Various architectures have been proposed to implement these surfaces for protection applications in recent years. However, many of these structures rely on active elements such as PIN and Schottky diodes, which suffer from limitations such as low power handling, wide bandwidth, and poor selectivity.

This study introduces a novel frequency-selective limiting reflectarray, utilizing an innovative approach of integrating plasma cells into an absorptive resonant topology. The proposed design offers a distinctive response characteristic where the limiter transitions from a reflection state to selective narrowband absorption once the input power exceeds the threshold required for gas breakdown within the plasma cells. This mode change occurs due to a shift from constructive interference in the reflection mode to destructive interference in the absorption mode, facilitated by the altered dielectric properties of the plasma cell. The experimental results of the plasma-based frequency-selective limiting reflectarray will be discussed, showcasing its capability to effectively manage high input powers exceeding 100s of Watts. This power is substantially higher than what other limiting technologies can provide.