The Research On Beam Synthesis Of The Wire Grid Antenna

Since the invention of the telegraph by Marconi,wirless technology has played a key role in mobile communication,satellite communication,Radar system.Antenna is the important component to transmite or receive the data in the wireless system,thus the characteristic of the antenna has the direct influence in the wireless system.According to this, Antenna couldn't be ignored in the wireless system.Meanwhile with the development of the electronic technology in the military,more strict functions such as the ability to track more targets which are far away with fast speed ,are required in the Radar system.The wire grid antenna is a kind of low cost and frequency scanning antenna which has high gain , linear polarization,simple structure,low sidelobe,etc.Therefore,this kind of antenna has great value in Radar communication.So far, there are a number of research which are focused on the structure, the radiation theory, the analysis method.However, few articles concentrate on the beam synthesis.Most of the articles attempt to use Taylor distribution to taper the sidelobe, this method was limited due to that it couldn't be applied in the planar antenna array.Thus, it is necessary to search other methods to control the sidelobe of the wire grid antenna.In order to solve this problem, this article not only uses the traditional antenna synthesis method to taper the sidelobe,but also introduce the Genetic Algorthims to fulfill the antenna synthesis.Firstly, a short introduction about classic algorithm in traditional antenna synthesis are presented .Dolph-Chebyshev array and Taylor array are analysised.Secondly, Genetic Algorithm is applied in antenna synthesis and a linear antenna array was optimized by this method.Finally,the basic theory of microstrip wire grid antenna was analyized ,and two methods were used to optimize the array .What's more,a kind of microstrip wire grid array antenna was designed,the beamwidth of this array is smaller than 5 degree , the sidelobe in azimuth is smaller than -18dB,scanning area changes in frequency and the array produces shifts in the beam direction of approximately 20 degree.