Research And Design Of Vehicle Miniaturized Muitband Antenna

With the development of communication technology,modern military wireless communication requires increasingly higher information integration of combat vehicles.Meanwhile,in order to meet the needs of frequency hopping and spread spectrum technology,the antenna will inevitably develop in the direction of small size,wide frequency band and multiple frequency bands.Especially for the antennas working in the VHF/UHF frequency band,it will inevitably develop in the direction of miniaturization to improve the invisibility of communication equipment.This paper focuses on the realization of miniaturization,multi-band,wide-band and high gain of VHF/UHF band vehicle antennas.The main research contents are as follows:1.Research and design of VHF/UHF triband broadband miniaturized antenna.Based on the Hilbert fractal structure theory,a single-port fed double whip antenna is designed.The antenna is realized by two ordinary single oscillators connected by a transmission line.First,for one of the whip oscillator structures of the antenna,an LC parallel circuit is loaded at a quarter wavelength from the bottom of the whip oscillator to adjust the path length of the high-frequency operating current,which effectively improves the high-frequency pattern.Secondly,in order to reduce the Q value of the electrically small antenna,a transmission line transformer loaded with a ferrite magnetic ring is designed at the bottom of the antenna,making it more conducive to broadband design.At last,the genetic algorithm is used to optimize the design of the embedded lossless broadband matching network.Finally,the integrated design of the antenna is completed,so that the double whip antenna achieves the performance index of multi-band broadband miniaturization.2.Design of a novel type of antenna with plane fractal bending element.In order to improve the radiation efficiency of the antenna while keeping the longitudinal dimension of the antenna unchanged,this study proposes a design method of double whip antennas.The method utilizing a four-element bending dipole antenna coaxial structure as one antenna whip,and placing a dipole antenna on top of the other ordinary whip;Secondly,based on the Franklin antenna theory,a dipole in-phase antenna array working in the UHF band is designed,and a balun structure is loaded on the coaxial dipole feeder to ensure the balance of the feed current at high frequency;A broadband duplexer is designed to meet the feeding requirements of the antenna working in the VHF and UHF bands.Finally,based on the genetic algorithm,the embedded broadband matching network is optimized to realize the broadband of the antenna,and the integrated antenna coaxial design is completed.