Microwave Absorber And Its Applications In Antenna RCS Reduction Research

With the rapid development of the age of science and technology,the requirements for information and communication are increasingly high.How to achieve reliable and safe communication is very important for both military and civil applications.Radar radome can reduce interference to a certain extent,ensure the safety and reliability of communication,and reduce the radar scattering cross section of antenna,so as to achieve stealth characteristics.Therefore,as one of the important components of modern radome,microwave absorber is very important for both national defense technology and civil applications.The research of microwave absorber has become a hot topic in recent years.This paper mainly focuses on the analysis and design of microwave absorber and its application in the antenna radar cross section.A wide-band microwave absorber is designed and applied to the antenna to reduce the radar cross section of the antenna.The content of this paper can be summarized as follows:1.Study on frequency selective surface with high selective and wide bandpass:(1)The basic working principle of the substrate integrated waveguide cavity is analyzed,and a quarter substrate integrated waveguide cavity is designed to achieve the purpose of miniaturization;(2)By using the odd-even mode analysis method,the working principle of hole coupling resonator generation is analyzed;(3)A high selective band-pass frequency selective surface is designed and studied by using a substrate integrated waveguide cavity and a hole coupled resonator,and its experimental verification is carried out.2.Study on frequency selective absorber with bandpass:(1)The analysis method of circuit analog absorber is introduced,and the working characteristics of the absorber are qualitatively analyzed by using the equivalent circuit method;(2)According to the equivalent circuit,the physical structure of the absorber is studied and designed;(3)An example of band-pass frequency selective absorber is designed and verified experimentally.3.Study of frequency selective absorber with in-phase reflection phase:(1)The structure of artificial magnetic conductor is introduced,and its basic performance is analyzed;(2)The surface structure of the square ring artificial magnetic conductor is analyzed by using the equivalent circuit method;(3)The lossy resonant circuit is introduced,and the absorber with in-phase reflection phase is further designed,and its experimental verification is conducted.4.Application of frequency selective absorber with in-phase reflection phase in antenna RCS reduction:(1)The edge-fed microstrip antenna loaded with artificial magnetic conductor structure is studied and analyzed,and the effect of artificial magnetic conductor structure on improving the gain of microstrip antenna and broadening the working bandwidth of antenna is verified;(2)The in-phase reflection type frequency selective absorber is introduced and used as the floor of the side-fed microstrip antenna.Through comparison,its effect on antenna RCS reduction is verified.