An ultrawideband graphene microwave absorber for advanced stealth technology

Abstract Currently, microwave absorber designs primarily employ metallic patches on substrates, focusing on configurations of Frequency Selective Surfaces (FSS) in terms of optimizing shapes and sizes. However, these approaches often overlook material performance, leading to limited design flexibility and operational bandwidth. To address this gap, we introduce an ultrawideband, polarization-insensitive microwave absorber utilizing graphene resistive dual circular rings based FSS. Here, optimal graphene sheet resistance (10 Ω/square) in relation to its growth temperature (1015 °C) along with FSS design parameter optimization was performed to yield ultra-wideband absorption spanning X-, Ku-, and K-bands, covering frequency range from 10.3 to 22.8 GHz. Notably, this absorber performs exceptionally well over varying polarization angles for both transverse electric and transverse magnetic modes. Additionally, proposed absorber’s equivalent circuit model has been developed, which validates the absorptivity closely with simulated results. In terms of Radar Cross section (RCS) of the proposed graphene FSS based absorber, the monostatic RCS is well below −25 dBsm over wide bandwidth of 10 GHz and bistatic RCS shows RCS reduction appreciably below −25 dBsm over wide reflected angle range (−180° to 180°). These properties position the proposed absorber as a promising candidate for futuristic stealth technology, demonstrating its potential for enhanced stealth capabilities.