Research On The Method Of Optimization Of Large Spacing Array Antenna

Satellite communication technology is developing rapidly.In April 2020,the National Development and Reform Commission(NDRC)included the satellite internet in the scope of "new infrastructure".The terminal antenna has also come into a period of comprehensive development.To meet the requirements of high performance,low cost,and light weight of the terminal antenna,this designer more and more inclined to choose large spacing array antenna.Large spacing array antenna can achieve the gain of the full array antenna with the same aperture using fewer array elements.However,the minimum element spacing in a large spacing array antenna is greater than one wavelength,which results in the undesirable grating lobe in the radiation pattern of the large spacing array antenna.In addition,the side-lobe level of the array antenna is also an important parameter,it can affect the performance of the antenna array.A lower side lobe level can improve the resolution of the antenna and suppress the clutter.Therefore,how to avoid the grating lobe and reduce the side-lobe level reasonably is the main research topic of this paper.In the same aperture,compared with a full array antenna,the number of array elements in a large spacing array antenna is smaller,so the number of receiving and transmitting components used in the antenna system is also reduced.On the one hand,the production cost is reduced,on the other hand,the weight of the antenna is reduced.However,the large spacing array antenna has high grating lobes,this can affect the antenna's normal work.The sparse distribution of the array antenna makes it possible to suppress the grating lobe.Because of the complex and non-linear relationship between the radiation pattern function and the position of the array elements,intelligent optimization algorithms are often used to solve this kind of problem.In this paper,the radiation pattern optimization technology of the large spacing array antenna is studied.The genetic algorithm is improved,and it is used for the optimization of the radiation pattern.In the base of the optimized radiation pattern by the improved genetic algorithm,the radiation pattern of the large spacing array antenna is optimized again combining with the pattern search algorithm,so that the grating lobe is effectively suppressed.In addition,for the high side-lobe level of the array antenna,the amplitude weighting method is used to reduce the side-lobe level in this paper.For the array elements with randomly distributed,this paper proposes a new weighting method about window function to effectively reduce the side-lobe level of the array antenna.Finally,this paper introduces some basic knowledge of MATLAB software and GUI platform.A user interface for antenna test is developed by using the GUI platform of MATLAB software.This user interface has the functions of receiving and transmitting calibration,radiation pattern test and generate scanning code.This user interface makes the tedious test work easy and fast.In addition,the antenna optimized in this paper is tested by using this user interface in the microwave anechoic chamber,and compared with the simulation result.