| According to the characteristics of the UHF antenna used in the army, such as small size, high strength, high gain and broadband, and the phenomenon the resonance length of the thick dipole and the printed dipole be reduced obviously because of the influence of the dielectric, the relationship of the planar antenna structure and the electrical parameter is discussed. On the basis of the exposition of the method of moments and finite difference time domain method, the current distribution of the vertical planar antenna and the impedance characteristic parameters of the rectangle planar monopole antenna is analyzed, which testifies the wide-band characters of the planar antenna by utilizing the high frequency simulation software (HFSS). In this article, the finite difference time domain method is used to analyze the general planar antenna. An original structure of broadband and miniaturized H-shaped planar printed monopole antenna is designed firstly According to the band, the gain, the distribution of the surface current, the antenna patterns of the far field and the near field which are given by the HFSS. The frequency characteristics of the input impedance and the gain are also compared in this article.Proceeding from the theory of expanding the band and the feeding problem of the H-shaped planar antenna, the basic theories of the broadband network that are related to the subject is introduced. The discussion in this article focuses on the method of numerical optimization in broadband matching network, which is used to expand the bandwidth when the determined structure of the antenna is analyzed. Moreover, the feeding of the H-shaped antenna is especially studied. Considering that the scattered field existed on the feeding extension line of the H-shaped antenna would affect the parameters of the antenna, this article puts a T-shaped feeding structure designed according to the feeding edge feature and proves that it can meet the needs of the antenna bandwidth theoretically when the equivalent matching network is used. The standing wave and the characteristic of the radiated power of this printed antenna fed by the standard coaxial line are analyzed by the numerical method. The influence on the performance of the antenna produced by this feeding structure is studied quantification ally by the simulation on the computer. Comparing the influence of the standard and T-shaped feeding structures on the standing wave, radiated power and the band of the antenna, we find that the center resonance frequency can be adjusted by changing thelocation of the feeding of the outer conductor. By the simulation of the ANSOFT HFSS, the influence on the bandwidth and the gain affected by the varieties of the length of the outer conductor, the air-gap distance of the antenna and the ground is given out. Furthermore, the graphs of the relations of the structure and the standing wave will give some reference value to the engineering design. Considering the actual size of the feeding notch of the H-shaped antenna, a goal function with constraint conditions is advanced on the basis of the T-shaped feeding in this article. Then it changes into an unrestricted goal function through adding to the penalty function and gets a set of the external diameter values of the coaxial configuration which can match well with the antenna by optimization. According to the chosen values by optimization, the impedance matching device made of two-phase cascade coaxial line is switched into the antenna. The results show that the designed impedance matching device can expend the bandwidth of the antenna.The H-shaped antenna covered by the baton cover is proposed, which can solve the baton problem of the operational force armored cars. Through the simulation and the actual test of the H-shaped antenna covered by the baton cover, the standing wave bandwidth, the radiated power and the gain of the baton antenna are shown. Moreover, using the common whip antenna and the baton antenna carries out the actual test of the communication distance.According to the requirements of the airborne synthetic aperture radar antenna, the major technique of ultra broadband and miniaturized antenna for UHF and the current condition of airborne synthetic aperture radar antenna are analyzed at last. To the problem of its small size, high gain and broadband, the new feeding source of the prismatic plane radar antenna can be used by the two-element antenna array made of the double H-shaped right printed antenna. The radar antenna bandwidth is 2.2 times frequency, and the standing wave inside the band is less then 1.85. Moreover, the gain in the center frequency is more than 9.60dBi and the maximal gain is more than 12dBi. However, its weight is less then 3 kilograms and both the height and the width are less than 1 meter. The electric and non-electric parameters such as the band, the gain and the aerodynamics both meet the design demands. Today, it has already installed on the plane and the test-fly results are satisfying.
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