| There are many bands in the electromagnetic spectrum,among which the terahertz(THz,Terahertz)band is in the initial stage of exploration.The frequency range of terahertz is between0.1THz?10THz.At present,the relatively mature technology development in the related fields of the electromagnetic spectrum is only in the far-infrared and millimeter wave bands,and the related technologies in the terahertz band have still not been well developed.Nowadays,with the advancement of science and technology,people's demand for future science and technology has risen sharply.Terahertz wave plays an important role in the development of future science and technology,which makes terahertz technology have very broad application prospects in many aspects.For example,detection technology is a technical field that has been studied for a long time and is constantly updated.In recent years,how to improve the detection technology to the terahertz frequency band and improve the working efficiency of terahertz detectors has attracted people's attention.As the terahertz detection technology continues to approach maturity,related technologies that help improve the performance of the detector have also been rapidly developed.In the terahertz detection system,the terahertz antenna has always been a very important part of the detection system.The main work of this thesis is to study the antenna effect on the terahertz detector.It is our research goal to design a high-gain,wide-bandwidth and miniaturized terahertz antenna to realize the highly sensitive detection of the detector to the terahertz band.The specific research work and innovations of this paper are as follows:(1)An overall overview of the basic theory of the antenna,based on the existing theoretical research to further improve the antenna miniaturization and wide bandwidth method.According to the development results of terahertz technology at this stage,in-depth study of the structure and materials of the antenna.At present,there are many types of relatively mature antennas in the field of antenna research.This paper mainly chooses butterfly antennas,log-period antennas and helical antennas for preliminary research.The research method is based on the three basic design ideas of terahertz antennas: 1)The frequency ratio calibration method is adopted on the basis of traditional microwave antennas;2)The dielectric layer is optimized based on high-gain planar antennas;3)Based on new materials,design high-precision antennas.According to the antenna's reciprocity theorem(antenna reversibility),the antenna designed in this paper can not only be used for detection technology,but also has a lot of room for development in the field of radio frequency.(2)According to the antenna theory and the detection mechanism of the detector,the antenna effect on the terahertz detector is studied and analyzed.The antenna structure with better performance was designed and simulated in the early stage.Through simulation software,simulations were made for the effect of integrating planar antennas on terahertz detectors.Experiments are conducted to compare the differences in parameters such as response rate,noise and response time between detection devices with and without antennas.The simulation results are checked with the experimental parameters,and the actual utility of the planar antenna on the terahertz detector is discussed through the data.Finally,it is concluded that the integration of a planar antenna structure on the terahertz detector is helpful to improve the detection performance of the detector.(3)Research on fractal structure.From theoretical research to structural design,the fractal design method is discussed.The structural characteristics of the fractal antenna are studied by simulation.The space filling of fractal structure and the self-similarity of fractal nesting structure are explained.Combining the basic requirements of terahertz antenna design,analyze the feasibility of fractal structure in the terahertz band.The advantages of the fractal structure are applied to the relatively mature butterfly antenna structure,and the expected effect of the combination of the two antenna structures is predicted through simulation.Finally,the innovative antenna performance is verified through experiments.(4)Propose and simulate a fractal butterfly antenna.Based on the design theory of terahertz antennas,combined with the characteristics and advantages of the fractal structure.Use simulation software to optimize the proposed fractal butterfly antenna structure.Analyze the characteristics of the structure,the advantages of the structure,and the law of structural changes.According to the simulation results,the structure of the fractal butterfly antenna is finally optimized and the best working frequency band is screened.Finally,the antenna performance obtained by the structure under different materials is studied.And make an assessment of the analysis results.Finally,the simulation results and experimental results prove that the proposed antenna structure is an antenna with high gain,wide bandwidth and miniaturization.The fractal butterfly antenna developed has a positive effect on the energy coupling of the detector in the entire terahertz band from 0.1THz to10 THz.The fractal butterfly antenna can not only improve the response rate of the terahertz detector,but its splitable flexible structure also saves the design cost of the antenna.This thesis combines the two theories of antenna and detection,and analyzes and evaluates the development and application of terahertz antenna technology.And studied a new antenna structure,which combines the structural characteristics of the fractal antenna and the butterfly antenna.According to the basic principles of terahertz antenna design,the antenna structure developed is mainly used in terahertz detectors,and will be gradually expanded to the communication field in the future.The advantages of high gain,wide bandwidth and miniaturization of fractal butterfly antennas provide more room for development in terahertz detection.The high performance of the antenna proposed in this paper is mainly manifested in improving the responsivity of the terahertz detector.Through the research of fractal butterfly antennas,several ideas and methods of combination of fractal modules are proposed.The antenna structure proposed in this paper can be used not only in the field of detection,but also in medical rescue,radar,and communication technology. |
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