Research And Design Of High Gain Electric Scanning Antenna

Antennas are widely used in commercial and military fields.The higher the gain of the antenna,the longer the communication distance.Early military radars used mechanically scanned parabolic antenna systems.This type of antenna has the characteristics of high gain,but the scanning speed is low,which is not conducive to the detection of high-speed moving targets.The advent of phased array antennas has promoted the development of high-gain electrical scanning.However,the high-gain and high-resolution phased array antenna requires a large number of array elements,and the feed network will become more complex with the increase of the number of array elements,resulting in a sharp increase in cost.Therefore,in order to make the antenna system have high gain and low-cost scanning,the research and analysis of high-gain electronically swept antennas are of great practical significance.This thesis studies the design of low-cost and high-gain electronically scanned antennas.The main research contents of this thesis are as follows:First,the reflective high-gain electronically scanned antenna is studied.Firstly,this thesis studies the high-gain characteristics of reflector antennas,designs a feed-forward single-focus high-gain reflector antenna,and analyzes the causes and influencing factors of its high-gain characteristics;secondly,due to the design of multi-focal reflector antennas It is beneficial to slow down the gain variation in the scanning range,so this thesis analyzes and studies the multi-focal reflector antenna based on the array feed.Finally,in view of the small scanning angle range of the galvanically scanned reflector antenna,a high-gain galvanically scanned reflector antenna with a scanning angle of ±21°is designed by combining the sub-array technology,and its maximum aperture efficiency is 65.23 %.Compared with the literature with similar work,the designed scanning angle of this thesis is significantly improved.Second,a high-gain transmissive galvanically scanned antenna is studied.Firstly,the common slot-structured resonant metasurface elements are analyzed,and then two kinds of metasurface elements operating at 10 GHz are designed.Both unit forms can meet the phase compensation requirements of 360°;secondly,a high-gain metasurface lens with gradient phase is designed,which achieves an increase of 12.49 d Bi gain;finally,the method of loading a small phased array antenna as the feed is explored.The high-gain transmissive electronically scanned antenna achieves a scanning angle of ±30° by configuring the phase distribution of the feed.