Research On Low Profile Ultra-wideband Tightly Coupled Antenna Array And Absorber

Metamaterial absorber is a type of functional material that effectively absorbs incident electromagnetic waves and significantly reduces the target echo intensity.It can significantly reduce the target RCS,provide a new way for stealth technology,but also show great potential for the next generation of antenna design.In the past period,To achieve absorption control of electromagnetic waves,the research on the metamaterial absorber mainly focused on single-frequency “perfect absorbers”,multi-frequency “perfect absorbers” and polarization-insensitive absorbers,etc.Tightly Coupled Array antenna is a new research hotspot in the antenna field in recent years.At present,TCA antenna is still in the initial research stage.Although many achievements have been made,there are still some technical problems that hinder the application of engineering.Tightly Coupled Array antenna technology that based on millimeter wave absorbers,provides a new idea for improving antenna performance.This paper focuses on the study of metamaterial broadband absorbers and Tightly Coupled Array antennas.The main research content of this paper are as follows: First of all,this paper describes the development history of metamaterial broadband absorbers and Tightly Coupled Array antennas,and determine the research direction and innovation of the paper.Then analyze the derivation of the theoretical part with the design of the broadband absorber and Tightly Coupled Array antenna.It lays a theoretical foundation for the following simulation design and sample processing.Then,Based on the multi-resonant mode theory and the multi-layer resistive type frequency selective surface absorber principle,two different types of broadband absorbers are designed and the processed samples are tested.On one hand,based on the multi-resonance mode theory,a composite single-layer wideband microwave absorber structure,which operating in the X and Ku bands,is designed.By designing the unit size reasonably and selecting the appropriate array of combinations for different units.It can produce multi-resonance point absorption,greatly expanding the operating spectrum range of the single-layer absorber structure.On the other hand,based on the theory of multi-layer resistive frequency-selective surface metamaterial absorbers,an ultra-wideband absorber with a four-layer resistive film structure is designed and fabricated,achieving better than 90% absorption in the 0.85-8.5GHz frequency range.Finally,based on the broadband absorber design method and Tightly Coupled Array antennas theory,a one-dimensional Tightly Coupled Array antenna with a wideband absorber structure is designed and fabricated.The array antenna consists of a broadband absorber,a slotted bowtie-shaped element,a parasitic element,and an ultra-wideband microstrip balun.The broadband absorber consists of a two-layer structure with a lumped resistor.On one hand,it achieves a smoothly absorption of incident electromagnetic waves over a wide range.On the other hand,it eliminates the short-circuit zero and extends the antenna operating bandwidth.The array radiating element is composed of a slot-shaped bowtie-shaped antenna.The purpose is to extend the antenna operating bandwidth by changing the coupling capacitance value.The parasitic element is to solve the obvious truncation effect of the edge of the finite antenna array.Through simulation and testing,the correctness of the design scheme is verified.