| In recent years,communication systems have increasingly high requirements for multifunctionality and high integration of equipment,and antennas,as vital components of communication equipment,have put forward higher requirements for the miniaturization and multi-band characteristics of antennas.Traditional antenna miniaturization technology can no longer further reduce the size of antennas.Metamaterials are a kind of artificial composite structures with unique physical properties,after nearly 30 years of development,metamaterials have been widely used in many fields to manufacture components with excellent performance.The unique backward wave characteristics and sub-wavelength structure of the metamaterial unit are used in the design of the antenna,which can make the microstrip antenna break through the limitation of the traditional halfwavelength and further reduce the size of the antenna.With the deepening of its research,a variety of metamaterial-based antennas have been proposed.Based on the above questions,this paper conducts the following research:1.Based on the application of metamaterials in multi-band and miniaturized antennas,a metamaterial antenna with CSRR structure etched in the radiation part of the microstrip antenna is proposed,and a low-frequency resonant frequency band is added to the microstrip antenna,which is2.36～2.49 GHz,and the usable frequency bands of the final microstrip antenna are 2.36～2.49 GHz and3.18～4.76 GHz,which realizes the miniaturization and multi-band characteristics of the antenna.Based on the design method of magnetic resonator,a metamaterial unit with negative characteristics of magnetic single is designed.The unit presents left-right symmetry as a whole,and analyzes the metamaterial unit by full-wave simulation analysis method and S-parameter extraction method,its magnetic single negative frequency band is 2.28～2.76 GHz,and then the unit is used as the radiation part of the microstrip antenna,using CBCPW feeding,and finally the metamaterial antenna has three resonant frequency bands,which are 2.40～2.44 GHz,4.38～5.16 GHz,5.61～6.22 GHz,And it has good omnidirectional radiation characteristics in each resonant frequency band,and can be used for communication equipment in Wifi,WLAN and n79 bands.2.Based on the design principle of magnetic resonator,a new type of magnetic negati ve metamaterial unit is designed,the magnetic resonance frequency band is 5.19～5.69 GHz,t he metamaterial unit is loaded into the back of the monopole antenna,a new working freq uency band is added for the monopole antenna,and the final designed metamaterial antenna can work in the Wi MAX3.5GHz and WLAN5.8GHz frequency bands3.Based on the design principle of electromagnetic resonator and substrate coupling,a double-sided left-handed material unit is designed.Firstly,a dual-band metamaterial unit with negative permittivity is designed,in order to introduce magnetic resonance,a unit of the same size is added on the other side of the dielectric substrate,a ring current is formed through the coupling between the substrates,and the magnetic resonance is introduced to achieve the double negative characteristics,and the equivalent electromagnetic parameters are extracted by the S-parameter inversion algorithm to verify its double negative characteristics,and its double negative frequency band is 3.54～3.63 GHz and 7～7.54 GHz.The unit was added to the microstrip antenna,and two new frequency bands were added to the microstrip antenna,realizing the multi-band of the antenna,and finally designing a small four-band microstrip antenna. |
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