Design Of X-Band Light-weight High-gain Antenna Array

With the continuous evolution of military forms and the development of electronic technology,radar,as the main source of information in war,has always been the focus of attention of scholars in this field.In the modern radar system,its component array antenna is paid much attention.In this paper,based on the actual engineering requirements,an X-band array antenna has been designed.The antenna has the excellent performance of low sidelobe,high gain,small size and light weight.It can form sum or difference beam on the azimuth plane and carry out electrical scanning on the pitch plane.In this paper,under the condition of investigating the research status at home and abroad and mastering the relevant basic theory,according to the design index to determine the antenna array distribution and size,including row antenna spacing,row antenna size and spacing of each unit on the line,etc.Taylor synthesis method is used to determine the amplitude and phase distribution of each antenna element.The common antenna forms are analyzed,and the element form of the antenna is determined by considering the bandwidth,quality and other indicators.The direction diagrams of ideal Taylor distribution excitation and superposition prediction engineering realization error excitation are calculated by using MATLAB software.The reasons for the errors in the implementation of the project and the ways to deal with them in advance are discussed.Based on the above analysis,the design scheme is drawn up.According to the theoretical foundation and demonstration scheme,the HFSS software was used for simulation design.First,a printed microstrip array with an operating frequency band from fl to fh loaded with integrated baluns was designed.Secondly,the topology of the network is reasonably designed while ensuring good feed performance of the line feed unit distribution network.At the same time,a copper-clad upper and lower surface of the dielectric board and densely metalized through holes are punched at the edge of the copper-clad microstrip line.As a method for the inner conductor of the stripline,simulation verified the consistency of the electrical performance of the stripline with the traditional stripline,thus designing a thirty-two power division network.Then a planar microstrip line-strip line transition structure was designed.The strip line feeder network and the microstrip printed array were printed on the same dielectric board to realize an integrated line feeder array.The whole array was simulated,and the simulation results met the index requirements.Finally,a processing test was performed on the one-to-two power division network and the line-fed array antenna.The test results are in good agreement with the theoretically predicted results and basically meet the design indicators.Among them,the voltage standing wave ratio of the one-point thirty-two power divider network and the linear array of the line-fed unit array is less than 1.5 in the working frequency band,and the amplitude distribution of each port of the power divider network is not much different from the simulation result.In the microwave anechoic chamber,the directional pattern of the line-fed unit was tested with a planar near-field measurement system,and the electric average of the side lobe of each frequency point azimuth plane was below-25 d B;the line-fed unit was tested with a cylindrical near-field measurement system,The measured gain is obtained through the comparison method,and the gain of each frequency point is greater than 22 d Bi.In addition,the size and weight of the line feed unit meet the index requirements.The above shows that the engineering application value designed in this paper is high and can be well applied to actual projects.