Study Of Waveguide Absorber And Antenna Design Based On Metamatetrials

Metamaterial is an artificially synthesized artificial material that has a special quality.The geometry,size,direction and arrangement of metamaterials give it the ability to change the amplitude,phase,polarization mode and propagation mode of the incident electromagnetic wave.Compared with traditional absorber,metamaterial absorber has lower material requirements,higher absorptivity,simple design,and insensitive polarization angle and incident angle.Compared with traditional antenna,metamaterial antenna has the advantages of high directivity,high radiation effciency and miniaturization.The main research contents and significance of this paper are as follows:1.Designed a metasurface waveguide absorber with.high absorptivity.Based on spatial Kramers-Kronig absorbing principle,metasurface waveguide with discretization KK relationship space surface impedance distribution is built,Combining the relation between the dielectric coefficient and the surface impedance,waveguide metasurface with the space surface impedance KK relationship also has absorbing effect,and respectively compared 5,10,20 layers absorbing effect of the structure,proving that the structure with 20 layers can achieve good absorbing effect,and the electric field intensity distribution diagram of electromagnetic wave propagation in the metasurface waveguide is given.The metasurface waveguide structure designed in this paper can achieve 99%absorption at the designed frequency point of 10GHz.Finally,experiments are carried out to verify the absorption effect of the designed metasurface waveguide absorber,At the same time achieving more than 80%absorptivity in 9-11.5GHz band.2.Designed a bianisotropic metamaterial antenna with expanded beam width.Based on the field radiation distribution of patch antenna,the beam width of patch antenna designed is 82.1 degrees and 85.4 degrees respectively in surface E and surface H.Then,two kinds of basic magnetoelectric coupling of bianisotropic metamaterials are introduced.In this paper,metamaterial structure is placed above the patch antenna.The radiation field of the patch antenna is coupled with the metamaterial to achieve the effect of broadening the beam width.In this paper,the design of cuboid metal bar,LC oscillating metal bar,electric resonance split ring,magnetic resonance split ring,chiral resonance ring and other structures failed to achieve the ideal effect.Finally,the bianisotropic resonance ring designed in this paper can optimize the radiation efficiency of the patch antenna from-10.98dB to-27.6dB,and expand the beam width to 136.3 degrees and 111.9 degrees,respectively on surface E and H.3.The innovation of this paper is that when the designed metasurface waveguide surface impedance satisfies Kramers-Kronig relation in space,theoretically it can be proved that the structure can form a perfect absorbing effect on the incident electromagnetic wave.Without changing the structure of the patch antenna,the antenna radiation efficiency and beam width can be improved by coupling the bianisotropic metamaterials with the field of the patch antenna.In terms of principle,The absorption and radiation of the metasurface waveguide absorber and the metamaterial antenna designed in this paper belong to the reciprocity process.In terms of application,metamaterial antenna can achieve good signal coverage in space,while metamaterial absorber can reduce unnecessary electromagnetic radiation.