Research And Design Of Wide-band Metamaterial Absorber Based On Metal-dielectric-metal

With the rapid development of the electronic technology and communication industry,high-power,high-field-strength radiators at industrial frequency,highfrequency,or microwave band are increasing day by day.These artificial electromagnetic radiations leak into the environment to endanger human health and ecosystems and the electromagnetic pollution becomes increasingly prominent.At present,electromagnetic radiation has been listed by the World Health Organization as the fourth largest source of environmental pollution after water,atmosphere and noise.The metamaterial absorbers with exotic electromagnetic properties can realize perfect absorption of narrowbands by adjusting the structure of cell unit,which can help to solve the electromagnetic radiation problem.Therefore,metamaterial absorbers have important application value in the fields of stealth weapons,electromagnetic protection and electromagnetic pollution control.How to promote the absorption of metamaterial absorbers to realize their practical value with a broadband absorption has become one of the hot topics of current research.This paper is focused on metal-dielectric-metal three-layer structural metamaterial absorber.According to the impedance matching and attenuation absorption principle of the absorber,a new type of broadband absorber with a wide absorption bandwidth is proposed by means of loading resistive device.It has a significantly higher absorption effect than that without the resistive device.The simulation results show that the absorptance over 50% is 200 times wider than that of the non-loading resistance.The metamaterial absorber with loading resistance can absorb electromagnetic waves from 11 GHz to 32 GHz,with the absorptivity exceeding 50%.Meanwhile the total bandwidth of the absorptivity over 90% can be as high as 9.62 GHz.We use the equivalent circuit theory to qualitatively analyze the reasons why the loaded resistor metamaterial absorber can realize broadband and high absorption.In this paper,the effect of various structure parameters on the absorption performance has been discussed in detail.Therefore,when designing the broadband metamaterial absorber,the influence of various parameter variables needs to be comprehensively considered.We use Sparameters to calculate the equivalent electromagnetic parameters of the metamaterial absorber,and verify the rationality of the loaded resitance metamaterial absorber.In order to broaden the application range and practical flexibility of the metamaterial absorber further,the dynamic tunable broadband metamaterial absorber is desperately needed.In this paper,the tunability of the absorber with loading capacitors is discussed.The simulation results show that variable capacitance can effectively adjust the position of the absorption peak frequency.Finally,taking advantages of the capacitors and resistors simultaneously,we have designed a broadband tunable metamaterial absorber with capacitance and resistance.The simulation results show that this kind of capacitive and resistive broadband metamaterial absorber structure shows good tunable characteristics and wide-band absorption properties.Our above work lays a foundation for the practical design of broadband tunable metamaterial absorber.