| The function of an antenna is to convert an RF signal from a transmitter to a propating electromagnetic wave or convert a propagating wave to an RF signal in a receiver.Antennas are playing a crucial role in the domains of Radar and Communication systems. The performance of Antennas directly affects the usage of Radar and Commucation system, the security in Radar and Commucation system and the result of the military affairs.The dissertation advances a double-direction waveguide slot antenna by studies of different kinds of antennas and the use in the different surroundings, and describes the important affect in the domains.In this dissertation, the theory of electromagnetic fields in waveguide transmission mode is derived in detail. We have received the field expressions of the main mode TE10. Waveguide slot antenna is given detailed analysis. First, waveguide slot can be equivalent to magnetic tape. By the use of electromagnetic theory, Green’s function of internal waveguide and external half-space and boundary conditions,we have derived the integral equations and obtained the result of the electric field in the slot. Secondly, through the analysis of the slot voltage and the mode voltage and the Mutual coupling, we find the relationship between active admittance and the slot parameters and have founded the functions of active admittance of waveguide slot antenna. And they can be simplified into a microwave circuit. Through the use of Electromagnetic field simulation software HFSS and Matrix calculation software Matlab we can calculation the value of active admittance. Through analysis of array antenna and synthesis of array antenna and decomposition of technical indicators the design of the antenna has been completed, and meet requirements of the target of antenna pattern and gain.Through the use of commercial software we improve efficiency of the antenna design and this method is good and accurate. This antenna in this paper which has some improvement is different from the previous antenna. At the same time, the radiation antenna have replaced the load of traveling wave antenna and completed the change in the direction of the beam. This antenna has a good flexibility,a good adaptability,good radiation efficiency, a good reliability, a light weight and a simple structure. After the program argues and the indicators of analysis and test validation, the antenna has obtained the identification of experts, good evaluation and acceptance of higher-level departments. The antenna meet the needs of system,and we get the desired results. |
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