Research And Design Of Missile-borne Broadband Conformal Antenna

In modern information warfare,the performance requirements of precision guidance technology and weapons are getting higher and higher.However,under special installation conditions such as missile-borne and air-borne,the installation space of the equipment is even more tight.The antenna mounted on the surface of the missile must have low-profile physical characteristics to be conformally installed with the surface of the missile to avoid damaging performance of the missile.Therefore,broadband conformal antennas are becoming more and more popular.In this paper,the active and passive composite seeker is used as the carrier,and the log-period antenna and Vivaldi antenna are selected as the antennas.The log-period antenna and Vivaldi antenna are conformaled to the metal surface of the circular table,and design the miniaturized type.So the antenna can form an antenna array of six elements.The main research contents are as follows:First of all,a printed board-type anti-heel Vivaldi antenna is selected as the conformal antenna solution.Based on the sharp deterioration of the antenna performance after conformal design,an all-metallic Vivaldi antenna with more stable radiation and simpler structure is innovatively proposed to conform to the surface of the missile.In order to improve the antenna gain and reduce the VSWR,the antenna is optimized by acting a “Y”-shaped slot on the side of the antenna.The absorbing material is introduced as the filler between the antenna and the missile.The simulation results show that the antenna's radiation performance and matching performance are greatly improved.Secondly,a microstrip log-periodic antenna is designed,which is conformal to the surface of the metal carrier.Due to the demand for the miniaturization of the four longest pairs of vibrators,a tree-like fractal structure is innovatively introduced to the conformal log-period antenna.After the fractal design,the maximum lateral size of the antenna is reduced by about 47%.The electrical performance of the antenna still meets the technical index of 5.5d B beam width reaching 60 degrees.The fractal antenna is conformed to the surface of the circular truncated metal missile to form a six-element antenna array,thereby achieving omnidirectional radiation of the antenna array.In addition,a log-period antenna loaded with an inductance structure is designed,and the lateral size of the vibrator is reduced by the form of loading inductance.By comparing the advantages and disadvantages of the two miniaturization methods and the antenna performance,the optimal antenna design scheme was obtained and the antenna prototype was processed and tested and compared with the simulation results.In this paper,two forms of log-period antenna and Vivaldi antenna are used to research and design the antenna conformal.The Vivaldi antenna adopts an all-metal structure with a “Y”-shaped slot design to achieve the purpose of increasing gain.The antenna is formed into a six-element array,and the gain and beam width of the antenna elements in the array meet the indicators of 5.5d B beam width 60 degrees;The microstrip log-period antenna adopts a tree-like fractal structure to achieve the purpose of miniaturization.The antenna prototype has been processed and tested.The measured results are consistent with the simulation results and also meet the indicators.