Research On Wide Angle Scanning Array Antenna

Compared with the traditional mechanical scanning antenna,the phased array antenna scanning has the advantages of small volume,light weight,fast scanning speed and good stability.Since the pattern of the array antenna is the product of the active unit pattern and the array factor,in order to enable the array to have a relatively small gain fluctuation during the scanning process,it is often required that the beam width of the active pattern of the antenna unit is as large as possible.Therefore,designing an array element antenna with wide beam characteristic is a key entry point for studying wideangle scanning array antennas.In this paper,the following work has been done on wideangle scanning unit antennas.Firstly,it expounds the background and significance of the topic,and briefly summarizes the research status of wide-angle scanning array antennas at domestic and abroad.Secondly it elaborates the basic theory of the phased array antenna,including the basic parameters of the antenna,the common structures and methods of realizing the wide beam unit pattern,and the influence of mutual coupling on the active input impedance of the antenna in the array environment.In the third chapter,it describes a novel design about a one-dimensional wide beam unit antenna,the 3dB unit beam width of the antenna reaches ? 70 degrees,and the antenna has good isolation index as the array element.In the case of half-wavelength array,the isolation can reach-25 dB.It is processed into a 1×8 one-dimensional linear array.The simulation and actual measurement show that the antenna has good onedimensional wide-angle scanning performance.The fourth is to design a radiation pattern reconfigurable square-loop antenna.By using five different feed combinations,the antenna can achieve a normal radiation pattern and four tilt pattern.Using these five patterns to apply it to the non-uniform sparse array and performing Matlab simulation experiments,experiments show that the reconfigurable antenna can be perfectly suitable for the sparse array.Because of the small units number of sparse array,the gain is not as high as the full array.But this radiation pattern reconfigurable antenna can improve the low gain shortcoming of the sparse array because of the high gain of its five different patterns.In summary,this radiation pattern reconfigurable antenna used together with sparse array has practical engineering application value.