Design of a wideband and tunable radar absorber

Abstract

To effectively address the challenges posed by intricate and dynamic electromagnetic environments, we propose a wideband and tunable radar absorber in this paper. The proposed absorber, composed of graphene capacitor, plasma enclosed within a sealed glass cavity, radar absorbing material (RAM), FR-4 and copper plate, allows for tunable radar absorbing performance through the manipulation of the electromagnetic properties of the graphene capacitor and plasma. Based on the equivalent circuit model, the reflectivity of the radar absorber is analyzed using transmission line theory (TLT). Good agreement is observed between the full-wave simulations and the TLT. The study thoroughly investigates the influence of graphene, plasma, and RAM components, as well as their sequential arrangement within the radar absorber, on its reflectivity, expounding the fundamental mechanism of these materials’ synergistic integration. Additionally, the effects of key factors, including the surface resistance R _g of graphene, plasma frequency ${w}_{p},$ collision frequency ${v}_{p}\,$ and plasma thickness ${t}_{{plasma}},$ on the radar absorbing performance are examined. Our findings reveal that adjusting surface resistance R _g controls the absorbing amplitude, and manipulation of the plasma frequency and collision frequency tunes the absorbing frequency and effective absorbing band. By appropriately adjusting the surface resistance R _g of graphene, plasma frequency ${w}_{p}\,$ and collision frequency ${v}_{p},$ the proposed radar absorber exhibits superior performance in the frequency range of 1 GHz to 10 GHz. The radar absorber we propose serves as a significant reference for the application of tunable radar absorbers and adaptive radar stealth techniques.

Keywords

• graphene
• plasma
• transmission line theory
• tunable radar absorber
• adaptive radar stealth