Research On The Radiation Enhanced Leaky Waveguide

Leaky waveguide structure has dual role of transmitting and radiating electromagnetic energy.Not only can they transmit electrical signals along the axial direction,but also can radiate electromagnetic waves along the radial direction.They are often used in closed or semi-closed space,such as subway,highway,high-speed railway,airport,tunnel,shopping mall and office.The electric signal generated by the leaky waveguide covers uniformly and there is no blind area,what is more,the communication path can be changed as needed,and the electromagnetic pollution to surrounding environment is very few.The research to leaky waveguide is a hot spot in the field of basic communication research.The radiation characteristics of the leaky waveguide are closely related to the structural parameters.In case the leaky waveguide is manufactured,its structural parameters are fixed and the radiation characteristics are fixed.Which causes the capacity to adapt the environment of traditional leaky waveguide is weaker.In complex communication environment,leaky waveguides often face the trouble of insufficient radiation intensity and cannot achieve good electromagnetic coverage.In order to solve this problem,radiation enhanced leaky waveguide structures is proposed in this paper to significantly improve the radiation performance of the leaky waveguide by add special electromagnetic structure on the traditional leaky waveguide Since the work area is often located on one side of leaky waveguide,which is usually in the positive direction of the slot or slot positive direction for short,therefore,this article focuses on the method to enhance the radiation intensity of the leaky waveguide in positive slot direction,mainly to solve the problem that less radiation intensity in some important regions.In engineering,the leaky waveguide structures used most are leaky coaxial cables and rectangular leaky waveguides,so,it is necessary to research that two structure.The main work of this paper as follows:1.For the leaky coaxial cables or leaky cables for short,put forward three kinds of reflector and a kind of dielectric layer.Through simulation analysis,obtained the influence that the main parameters of various additional structures to the far field pattern and the field intensity distribution on the extraction line at distance of two meters from the gap,and compare the improved structure with the best parameters in research and the traditional leaky cable.and prove the validity of these two methods for the improvement of the leaky coaxial cable.Finally,the two methods are used together to further improve the radiation performance of the leaky coaxial cable.2.For the rectangular leaky waveguide,put forward two kinds of reflector and a kind of dielectric layer.According to the requirement of radiation distance used in practical applications,concretely study the radiation intensity at 33 cm above the slot of the rectangular leaky waveguide.Through simulation analysis,obtained the influence that the main parameters of various addition structures to the field intensity distribution above 33 mm of the rectangular leaky waveguide,and compare the improved structure with the best parameters in research and the traditional leaky cable.Results from the study can be seen that the two methods of adding reflector and adding dielectric layer can significantly increase the radiation field intensity in positive of the gap of the rectangular leaky waveguide,and it is proved that these two methods are effective for the improvement of the rectangular leaky waveguide.Finally,the two methods are applied cooperatively to the rectangular leaky waveguide according to their characteristics,to further improve the radiation performance of the leaky waveguide.