Research And Design Of Artificial Magnetic Conductor In Microwave Antenna And Circuit

In recent years,with the rapid development of 5G communication system,people put forward new requirements to the performance of communication equipment,and higher performance requirements of receiving and transmitting antenna.In order to improve the antenna's return loss and gain,artificial magnetic conductor has gradually become hot issues in electromagnetic field.The artificial magnetic conductor(AMC)structure is composed of periodic metal patch,substrate and ground.Compared with traditional electromagnetic band gap structure,the periodic structure has the characteristics of magnetic conductor and electromagnetic band gap structure at the same time.it is easier to process.Simulation and preparation are also easier.This paper introduces the basic principle of formation of artificial magnetic conductor firstly.When one medium is arranged periodically in another medium,the electromagnetic wave in one certain frequency range will not propagate,so it has the characteristics of stopband.Therefore,it is also called high impedance surface.The characteristics of artificial magnetic conductor,caused by resonance at one certain frequency point,lead to the infinitely high impedance,which produce a high impedance surface and the characteristics of magnetic conductor.The main contents of this paper are as follows:Firstly,the developments of artificial magnetic conductor and the applications of artificial magnetic conductor in microwave and millimeter wave circuits and antennas are introduced.The developments of artificial magnetic conductor in antenna and filter are mainly introduced.Secondly,a triangular microstrip antenna is designed to realize the bidirectional radiation.According to the in-phase reflection of artificial magnetic conductor within the frequency band,the periodic artificial magnetic conductor is used as the reflector.Compared with the electric conductor,the antenna profile is greatly reduced.Because the distance between the metal reflector and the antenna is less than 1 / 4 wavelength,and the antenna has good radiation performances on one side of the artificial magnetic conductor reflector,the low profile antenna with high gain is realized.Thirdly,a periodic AMC structure and a dual-frequency antenna based on the substrate integrated waveguide are designed.Utilizing the in-phase reflection periodicity of AMC,when the resonant points of the dual-frequency antenna fall into the in-phase reflection frequency range of AMC,the gains of the dual-frequency antenna are enhanced,and the return loss are further improved.Finally,the applications of artificial magnetic conductor in microwave circuit are also researched.The low insertion loss of microstrip filter can be obtained with artificial magnetic conductor.A structure of fourth-order coupled resonator filter with AMC is designed.It is found that the simulation results are similar with the measurement,which proves the valid theory.It provides a new possibility for the further research of artificial magnetic conductors in microwave circuits applications.