Research on broadband tunable metamaterial absorber based on PIN diode

Radar absorbing materials (RAMs) have been widely applied in the fields of electromagnetic shielding and target camouflage. The current radar absorbing materials are passive, and the frequency response and absorption features are fixed as soon as they are prepared, which limits their further application in the future. In this work, a sort of state-of-the-art broadband tunable radar absorber is designed, fabricated and measured. The active metamaterial absorber and passive absorbing honeycomb are creatively combined together to achieve the overall absorptance of less than -10 dB in frequency range of 7(similar to)22 GHz. Furthermore, PIN diodes are introduced into the metamaterial radar absorber. By adjusting the bias voltage of the PIN diode array, the radar absorbing property can be actively tuned in a wide frequency range in the condition of broadband and high efficiency absorption.