| Over-the-horizon combat is the mainstream combat method in the information war.As the main weapon of over-the-horizon combat,missile plays a decisive role in the military strength of the country.The threat of missile depends not only on the explosive power of missile itself,but also on precise guidance technology.The excellent guidance technology must rely on antennas with excellent radiation performance.Therefore,the research of missile-borne antenna is of great significance.The concealment and anti-jamming characteristics of modern missiles require the bandwidth of missile-borne antenna.Considering the size of missile interior space,miniaturized ultra-wideband antenna is the best research object.With the further development of missile technology,more and more performance requirements of missile-borne antenna are required,such as high gain,wide beam,dual polarization and so on.In this paper,four miniaturized ultra-wideband antennas are designed according to different design requirements.The main research work is as follows:1.Two small aircraft conformal antenna antennas are designed.The operating frequency of the antennas is 400MHz-2GHz.The first one is a miniaturized monopole Vivaldi antenna.This antenna increases the bandwidth of the antenna by slotting and end loading on the antenna,and realizes the miniaturization of the antenna on the premise that the performance of the antenna meets the requirements.Compared with the traditional Vivaldi antenna,the height of the antenna is reduced by 61%,the length is shortened by 33%,and the performance meets the requirements.Then,some factors affecting the bandwidth of the antenna are studied.The second antenna is designed to be placed in the tail with the metal steering shaft.The presence of the metal steering shaft further reduces the usable space,and the tail wing is unable to accommodate the first antenna.Therefore,a ultra-wideband monopole antenna is designed,which can realize end-fire radiation by means of steering shaft.The antenna uses a butterfly metal sheet to increase the bandwidth,and the height of the antenna is reduced by slotting and short-circuit loading on the antenna.Compared with the first Vivaldi antenna,the height of the antenna is reduced by 11%and the length is shortened by 42%.Finally,a high temperature resistant antenna is made of stainless steel with high melting point.2.A dual-polarized conical sinuous antenna is designed.Based on the sinusoidal curve and referring to the design experience of planar sinuous antenna,a conical sinuous antenna is obtained by conforming the planar sinuous antenna to a frustum,the operating frequency of the antenna is 2.5 GHz-6.5 GHz.In order to realize the impedance transformation and balanced feeding of the antenna,an ultra-wideband balun is designed.Different circular polarization modes can be switched by changing the feed phase of the two balun.Finally,a kind of high power and shock resistant antenna is made by means of Laser Direct Structuring technology.3.A broadband low-profile horizontal omnidirectional antenna is designed.The traditional disk-cone antenna is taken as the research object.First,the antenna height is reduced by bending the vertebral body of the disk-cone antenna and increasing the cone angle.Then,the antenna performance at low frequency is improved by loading four short-circuit branches.After that,the single-disk structure of the original antenna is replaced by a double-disk structure to widen the antenna bandwidth at high frequency.Finally,the key factors affecting antenna bandwidth and omnidirectionality are analyzed.The operating frequency of the antenna is 2GHz-6GHz and the height of the antenna is only 0.09λmax,which is 47%lower than that of the traditional disk-cone antenna. |
