Research On A Metamaterial Absorber Based On Spiral Structures

Meamaterial is a new field and it have unusual electromagnetic properties.You can follow the wishes of the people to regulation its electromagnetic parameters,by changing the physical size and shape of the structure.Therefore,in recent years,researchers have explored to its with much studies.With the rapid development of electronics and information technology,countries in the military strength of the contest has evolved to become a contest of the electronics and information technology.In order to enhance the capacity of all aspects of weapons,many countries have stepped up exploration of stealth technology.Not only that,with the electronic products growing popularity in people's daily life,electromagnrtic pollution more and more serious.And it has impacted on people's health and the daily work.Absorbing materials are playing an increasingly important role in the protection of electromagnetic radiation and electromagnetic shielding.So,study metamaterial absorber has a very important practical value.Metamaterial absorber must meet two conditions that impedance matching and electromagnetic loss parameters.If it have an ideal impedance matching and a larger electromagnetic loss parameters,it can achieve the perfect absorption of electromagnetic waves.In this paper,we use the commercial electromagnetic simulation software.Designed a metamaterial absorber based on double spiral structures that can work in low frequency.In addition to,we also designed a broadband metamaterial absorber structure which loading lumped element.Through a mount of numberical simulation,the reflection and transmission parameter can be obtained which about the metamaterial absorber.Then calculate the absorption of metamaterial absorber.At the same time,we studied the polarization of electromagnetic waves and structure parameters effect on its absorbering.The main contents of this paper include the following aspects.It proposed a metamaterial absorber structure that based on double spiral structures.The resonant frequency of the structure is 2.02 GHz,absorption rate of 91%.It achieves efficient absorption of electromagnetic waves.The biggest advantage of this structure is its low resonant frequency.The thickness of the metamaterial absorber is 2.2mm,about 1/62 of the working wavelength.The disadvantage of this structure is the working bandwidth too narrow.Produced the double spiral metamaterial absorber structure by a printed circuit board using an etching technique.Using the microwave darkroom and vector network analyzer N5244 A to test the absorbing properties of the structure.The measured results indicate that the metamaterial absorber demonstrates a reflectance of-4.5dB at 2.2GHz.Meanwhile,this structure polarization-insensitive to the incident electromagnetic wave.It presents a loading lumped element(pure resistance combination)of broadband metamaterial absorber structure.Loading lumped element in the traditional structure of metamaterial which can effectively improve impedance matching and electromagnetic loss property.Reinforcing structure's absorption and broaden the absorption band.By a mount of numberical simulation,the working frequency of this absorber is 8.6GHz~18.3GHz,absorption rate at-10 dB or less,absorption band is 9.7GHz.This structure achieve the absorption of electromagnetic waves broadband.In addition,we studied the resistance value how to effect on the metamaterial absorber's absorbering properties.