Study Of Dual-tuned Broadband Electromagnetic Absorbers Based On Metamaterials

Metamaterial is based on some kind of artificial structure with specific function,we can design the key physical dimension parameters of materials to get artificial materials of superior function.This function do not be possessed by natural materials and not be restricted by the nature.Artificial electromagnetic material has been widely used in various fields because of its peculiar characteristics,such as electromagnetic stealth,electromagnetic black hole,optical lens,microwave devices and circuit,antenna.Nearly perfect electromagnetic absorber is one of the important application fields.The introduction of Artificial electromagnetic metamaterial makes new absorbers show unprecedented progress than traditional absorber in absorption frequency bandwidth,absorption,polarization sensitivity and geometry size.Classic nearly perfect electromagnetic absorber based on metamaterials is composed of three layers,it can be theoretically realized for 100% absorption of incident electromagnetic wave,its absorption spectrum is mainly decided of the top layer of metal structure unit with one or more electromagnetic response models.In this paper,in consideration of narrow absorption bandwidth of metamaterial absorber,we put forward dual-tuned broadband absorber based on double-square-ring shape with capacitance,-10 dB relative bandwidth is 81.4%;On account of commonly used wave-band of military radar,we propose dual-tuned broadband absorber working with C and X band,it almost realizes that absorption band dynamicly and electrically turn from 4 GHz to the 12 GHz,-10 dB relative bandwidth is 85.15%;As absorption frequency of electromagnetic absorber is high universally in low frequency,we come up with dual-tuned broadband absorber with AB face based on equivalent series inductance,the minimum value of absorption frequency is 1.06 GHz and-10 dB relative bandwidth is 81.9%,so it has good characteristics with low frequency broadband.The simulation results show that Reflection coefficients S11 of three new absorbers based on metamaterials within absorption band are below-10 dB,Absorption rate is over 90%,relative absorption bandwidth is over 80%.In this paper,in order to realize independent dual-tune,dual-tuned circuits of cross type and double parallel line type are presented.