Experimental Researches On Sub-wavelenth Plasma Enhanced Small Antenna Radiation

Sub-wavelength plasma modification and enhancement of electromagnetic radiation for compact radio-frequency(RF)antennas is a novel pioneer technology.It has important significance in science and broad applications in national strategic essentials,such as development of information network platform,RF communications and test/control technology,particularly communications and control technology for hypersonic flights,etc.In this thesis,effects of sub-wavelength-plasma enhanced RF electromagnetic radiation are discussed in experimental researches with numerical studies.The basis of this technology is revealed.The results can provide a technological foundation for a prototype device of sub-wavelength plasma enhanced electromagnetic radiation.The main research contents include:Numerical researches on sub-wavelength plasma enhanced small antenna radiationFirst,in order to design the parameters in the experiment,the near-field,far-field,and channel characteristics of the antenna covered by a sub-wavelength plasma are numerically studied with a spatial distribution of electromagnetic fields.The results show the radiation characteristic of small antenna enhanced by sub-wavelength plasma and the effect of plasma key parameters and interaction mechanism on radiation enhancement.The numerical results can guide proper parameter option for plasma and antenna to obtain an effective radiation enhancement in experiments.Principle experimental researches on sub-wavelength plasma enhanced small antenna radiationGuiding by the fundamental rules in numerical results,the experimental platform is design to achieve radiation enhancement.Changing the parameters of plasma source and the frequency of antenna,basic transmission characteristics such as characteristics of radiation gain,return loss,and channel property are studied to modulate and optimize the key plasma parameters that affect electromagnetic radiation transmission.On this basis,the radiation characteristics between antenna and plasma are established by measuring antenna radiation enhancement.The working characteristics of enhanced small antenna electromagnetic radiation modulated by sub-wavelength plasma structure are mastered by combining numerical results and data from plasma diagnostics.The enhancement mechanism of electromagnetic wave effected by sub-wavelength plasma structure is also studied in this work.Automation of experimental platform for the study of sub-wavelength plasma enhanced small antenna radiationAiming at settling problems in plasma data acquisition and processing by conventional a Langmuir probe system and the insufficiency of the principle experimental platform not being able to regulate and control plasma density automatically,the principle experimental platform is then optimized.The platform,which can monitor plasma temperature and control plasma density automatically in the plasma layer according to the requirement of the radiation enhancement,is designed and built.The results could promote the process of developing a prototype device.The experimental device in this thesis uses sub-wavelength plasmas to achieve a radiation enhancement on the small antenna as well as high efficiency of this experiment.These results provided the theoretical and experimental basis of research and development(R&D)of a prototype device of sub-wavelength plasma enhanced electromagnetic radiation.