Coded meta-materials drivened by impedance-mismatch: Ultra-broadband anti-reflection and scattering field manipulation

The inability of existing electromagnetic wave absorbing materials (EAMs) to manipulate electromagnetic waves in multiple dimensions leads to the failure to satisfy the demands placed on electromagnetic (EM) defense technology by the current complex EM environment. To break this dilemma, this study focuses on the impedance properties of EAMs, conferring additional ability to disperse and deflect reflected waves by encoding EAMs with opposite phase responses in different impedance mismatch modes. Due to the synergy of both absorption and scattering mechanisms, the developed scattering metamaterial absorber exhibits excellent anti-reflection performance, with reflectivity below 0.1 in the 7.8–16.7 GHz at 2 mm thickness. Furthermore, a genetic algorithm is employed to tailor the desired scattering field to meet the stealth requirements of specific environments, allowing for the directional transmission of EM energy in the one-dimensional or homogeneous distribution in the three-dimensional. The proposed scattering metamaterial absorber constructed by coded EAMs exhibited excellent anti-reflection properties and environmental stealth adaptability, opening up new possibilities for the development of advanced EM defense technology.