Blocking gate resonator rasorber surface brings wide band electromagnetic absorption performance approaching theoretical limit

In wide band electromagnetic absorbers, absorption in high and low frequency domain usually influence each other. Rasorber structure with blocking gate resonator (BGR) sub-wavelength unit surface is proposed and applied in electromagnetic wave absorber to resolve this problem. The absorber has −10 dB low-reflectivity performance operating in bandwidth ratio 161.2% and approaches Rozanov's theory limit in low frequency. BGR unit surface also generate a 2-step design method for multi-layer absorber structure. Rasorber BGR unit surface helps to enhance low frequency absorption with limited thickness while maintain absorption in relative higher wide frequency range by impedance matching at low frequency. Sample fabrication and experiment measurement basically testify the numerical speculations.