Research On Antenna Stealth Technologies Based On Metamaterials

Antennas are one of the strongest scattering sources,making a great contribute to the Radar Cross Section(RCS)of the whole system.Different from common scatters,transmitting and receiving of electromagnetic wave should be ensured while designing antennas with stealth property.As a consequence,researching about RCS reduction of antenna has great value.Metamaterial application research in antenna stealth design is carried out in this paper.Depending on different stealth theories including wave absorption and scattering wave to Non-threatening area,we studied stealth technology with metamaterial absorber basing on loss mechanism,artificial magnetic conductor(AMC)basing on destructive inference and antenna stealth basing on diffuse reflection random surface.The main contents and contributions are shown as following:Depending on the stealth theory of wave absorption,the first part researches about antenna stealth technology with metamaterial absorber basing on loss mechanism,describes relative theory about metamaterial absorber design,and designs miniaturized metamaterial absorbers which are polarization sensitive and non-polarization sensitive,which are used in antenna stealth respectively.The two designed antennas have obvious in-band RCS reduction while ensuring the radiance performance,covering the operation bandwidth fully,and also have stable large-angle incidence.Depending on the stealth theory of scattering wave to non-threatening area,the second part researches about antenna stealth technology with AMC basing on destructive inference,describes relative theory of designing antenna with AMC chessboard structure,and designs two AMC chessboard structures.Applied in antenna stealth,when the radiation performance is ensured or promoted,the first antenna with AMC structure and stealth property can provide RCS reduction of more than 6dB from 8.7 GHz to 12.1 GHz(48% relative bandwidth)in TE mode or from 8.7 GHz to 12.1 GHz(33% relative bandwidth)in TM mode,and the second one can provide RCS reduction of more than 7dB from 6.9 GHz to 14.2 GHz(69.2% relative bandwidth)in TE mode or from 6.8 GHz to 14 GHz(69.2% relative bandwidth)in TM mode.Experimental result of fabricated antenna is basically same with the simulation result,verifying the non-polarization sensitive stealth property of above antenna design.Basing on the research of part 2,in order to ensure the irregularity and non-direction of electromagnetic wave scattering better,the third part researches about antenna stealth technology basing on diffuse reflection random surface,describes relative theory about micro-strip reflection array,and designs a random surface composed of double loop-ring unit cell.This random surface is firstly used in antenna stealth design in this paper,while the radiation performance is ensured or promoted,this antenna can provide effective RCS reduction from 6 GHz to 20 GHz for normal-incidence plane wave(TE or TM mode).Average RCS reduction is more than 8.4 dB from 7.2 GHz to 12.7 GHz(55.3% relative bandwidth)in TE mode,and RCS reduction is more than 7 dB from 6.8 GHz to 14 GHz(58.6% relative bandwidth)in TM mode.Experimental result of fabricated antenna is basically same with the simulation result,verifying the non-polarization sensitive stealth property of this antenna design.