Design Of Ultra-wideband Absorbing Structure And Its Applications On Antennas

As a kind of absorbing material with strong on-demand design and multi-functional integration,electromagnetic absorbing structure has attracted the attention of many scholars since its birth.In the research of absorbing structures in recent years,most of the research and development work is mainly focused on the exploration of its versatility.The research and development progress on the basic aspects of traditional absorbing bandwidth,profile height and absorption effect is slow,and new ones are urgently needed.Based on the research of related literature and development status in domestic and foreign,this paper proposes a new idea to design ultra-wideband electromagnetic absorbers focused on the absorbing bandwidth problem,and adds more functions based on the new design ideas.A novel band-pass electromagnetic absorber is proposed,and the integrated design of the absorbing structure and antenna is also proposed.The main research work and innovations of this paper are as follows:1)The method of extracting the equivalent circuit form of the periodic structure and the equivalent parameters are briefly introduced to lay the foundation for the reader,and the change of the resistance loaded during the design process of the loaded resistive absorbing structure is analyzed.Then,the equivalent circuit of the absorbing structure is analyzed,and the factors affecting the upper limit of the absorbing bandwidth are pointed out.The method of using the multi-layer absorbing structure to break the influencing factor of the upper limit of the bandwidth is proposed.Designing an ultra-wideband absorbing structure by the guidance of an equivalent circuit.Finally,design and test the test platform for the experiment.2)The achievability of band-pass absorbing structure is verified by simulation.Then,based on the design of the ultra-wideband electromagnetic absorbing structure,the parallel resonant unit is introduced into the absorbing structure to realize the passband on the basis of ultra-wideband absorbing.Finally,the experimental test plan and the problems to be noted are described in detail.3)The connection between the antenna and the absorbing structure is clarified in the role of electromagnetic waves in space.Then,using the idea of the shared structure,the overall structure is reconstructed by designing a suitable switch loading method to achieve switching between the broadband antenna and the broadband absorbing wave.Finally,the ideal simulation results under the antenna state and the absorbing state are given respectively.