Research On Two-dimensional Multi-beam Antenna Based On Rotman Lens

With the continuous development of contemporary communication technology,the requirements for directionality,high gain and low cost for antennas in the civil and military fields are proposed,especially in the fields of communication base stations,missile guidance,millimeter wave passive imaging,space detection,etc.Multiple beams are generated at the same time to increase the scanning space and achieve greater airspace coverage.Common multi-beam antennas include phased arrays,reflective surfaces,and lens types.Rotman lens-based multi-beam array antennas have been researched and applied more and more because of their low cost,easy implementation and high reliability compared with larger reflector antennas and higher cost phased array antennas.Based on the existing technology and research results of Rotman lens,this paper further expands the application range.The two-dimensional multi-beam array antenna based on Rotman lens is comprehensively studied from theoretical analysis,design flow to simulation modeling and processing test.Using printed circuit technology,the processed microstrip antenna is used as a radiation unit to obtain a two-dimensional multi-beam array antenna based on a Rotman lens.The main research contents of this paper are as follows:1.The working principle of Rotman lens is introduced in detail,and the code is written according to the formula by MATLAB.The contour of the lens is designed by HFSS.At the same time,the microstrip line is used as the phase shifting structure to better maintain the broadband characteristics of the lens.The whole lens was simulated by CST,and the physical object was processed.The simulation results were in good agreement with the measured results.2.A back-fed linearly polarized and circularly polarized microstrip antenna was designed,and the unit was processed and tested.Then the linear and circularly polarized elements were combined into a linear array and a one-dimensional Rotman.The lens connection constitutes a one-dimensional array antenna,and the beam scanning capability and the circular polarization forming ability are analyzed and tested,and the results are in good agreement.3.Firstly use a linearly polarized antenna line array to form a two-dimensional area array,and a two-dimensional stacked lens group to form a two-dimensional beam array antenna connection,by strobing different input ports,the remaining ports are connected to the matching load,resulting in 7 × 7 A total of 49 differently directed beams,and then the linearly polarized antenna array is changed to a circularly polarized antenna array.By comparing the simulation and the measured results,it is found that the they have certain working capabilities in the design frequency band within a certain range.