Design Of Broadband Transparent Microwave Absorber

Microwave absorber,a component that can absorb the incident electromagnetic wave,is highly applicable in the field of stealth technology,electromagnetic compatibility,etc.With the extensive application of wireless communication and other electronic systems,the problems of electromagnetic interference and information leakage have become more prominent,and the microwave absorber takes an important role in coping with such problems.The classical microwave absorber has been unable to meet requirements of the modern environment because of its shortcomings such as narrow bandwidth and large thickness.In this thesis,the broadband optically transparent metamaterial absorber has been investigated.The main contexts and contributions are shown as follows:1.Two multiband metamaterial absorbers are proposed.A triple-band metamaterial absorber and a quintuple-band metamaterial absorber are achieved by combining different resonant structures.At the same time,the absorption mechanism of the multiband metamaterial absorber has been investigated.2.An optically transparent ultra-wideband metamaterial absorber is proposed.Glasses and indium tin oxide(ITO)thin films are used to construct the absorber unit to achieve optical transparency.Absorption rate of the proposed absorber is higher than 90% from 5.3 GHz to 17.45 GHz,and the fractional bandwidth reaches 106.8%.In addition,the absorption performance is insensitive to polarization and incident angles.3.A broadband transparent metamaterial absorber is proposed.There is an air gap between two glass substrates,thus the overall weight of the absorber structure is significantly reduced.Absorption rate of the proposed absorber is higher than 90% from 1.67 GHz to 3.8 GHz.The fabricated absorber sample is measured in an anechoic chamber.The measurement results are in good agreement with the simulations.