Research On The Method To Widen Scanning Range Of Phased Array

Wide-angle scanning phased array can provide more timely and effective information for guidance,recognition and tracking system in a larger exploration airspace,which shows a bright prospect in both military and civil applications.Thus,it is significant to study how to widen the scanning range of phased array.Based on the scanning principle and the pattern multiplication theory,the methods to widen scanning range from aspects of the array and the element are studied in this thesis.The main research results are shown as follows:Firstly,the scanning range of phased array is expanded by reducing the element spacing and changing the array’s structure.The simulation and experiment results show that under the condition of considering the array mutual coupling,the scanning range of planar array can be expanded by 14° only due to narrowing element spacing;the scanning range of curved array is 14° wider than that of the planar array,the range of the 2-faceted array is 12° wider and the range of the 3-faceted array is 34° wider.Secondly,the two methods of expanding beam width of the microstrip element by using the high order modes radiation and the three-dimensional ground reflection are firstly applied to widening scanning range.The simulation and experiment results show that the scanning range of the array with copper cylinder around is up to ±76°,and the array mounted on three-dimensional ground can steer its main beam from-81° to +81°,which has proved that the two methods have a great effect on widening the scanning range.Finally,this thesis adopts reconfigurable technology to widen scanning range by changing the structure of the radiation patch and the parasitic patch.Two kinds of pattern reconfigurable antennas are proposed in this thesis,and the simulation results show that the scanning ranges of the two designed arrays are ± 72° and ± 78° respectively,which has verified the effects of pattern reconfigurable technology in expanding the scanning range.