On The Omnidirectional And Directional Missile-borne Antennas

The thesis context is based on the research projects,the research targets are divided into two parts: The first part is the design of conformal array with the dual-band omni-directional pattern and circular polarization,which satifies the technical parameters basically.The second part has designed a kind of fan-shaped microstrip Yagi antenna,and measured results are well agreed with simulated ones.At the same time,the electrical performance of the antenna is simulated under the missile-borne installation platform.The simulation results show that the antenna has the value of engineering application.The main contents of the thesis are as follows:1.Design of conformal dual–band array with omni-directional pattern and circular polarization According to the requirements of low-profile and miniaturization,the design difficulties of the antenna is discussed and the corresponding solutions are given based on the antenna theory.Dual-fed microstrip antenna is selected as the conformal unit,and a Wilkinson power divider is used to achieve the 90 ° phase difference between the two ports so as to obtain the circularly polarized pattern.ANSYS HFSS is used to design and analyze the array,and the simulated results satisfy the requirements basically.In addition,the thickness of conformal antenna on the missile platform is 1.2mm.2.Design of missile-borne Yagi antenna with directional pattern A missile-borne antenna with directional pattern is studied.The radiator and director of the antenna are designed to be fan-shaped structures.Compared to the traditional microstrip antenna,the maximum radiation direction of the proposed Yagi antenna unit has a certain angle with the normal direction of the antenna.Measured results show that the operating frequency band of the antenna is 5.2-6GHz,the VSWR in the working frequency band is less than 2.3,the gain of antenna at center frequency 5.5GHz is 5.3d B,the angle between the maximum radiation direction and the normal direction(+ Z axis direction)is 58°,measured and simulated results are basically consistent.In addition,the electrical performance of the fan-shaped Yagi antenna in the missile-mounted platform are simulated and optimized.Simulated results show that the working frequency band of the antennaarray is 5.00-5.98 GHz,the inband VSWR is less than or equal to 2,the gain is greater than 6.97 GHz,the maximum radiation direction is along the direction of the bomb,this work laid a certain foundation for the follow-up engineering application research.