Analysis And Research Of The Multi-beam Conformal Antenna Arrays

Multi-beam antenna array is widely applied in military and civil fields,such as wireless communication system,local point-to-multipoint mobile communications,automotive collision avoidance radar and so on.In recent years,the research on multi-beam array antenna in civil fields has entered into the stage of high performance and low cost.Compared with traditional phased array,Multi-beam antennas has the similar performance with lower cost and higher practical application value.On the other hand,conformal antennas play a very important role in saving system size and beautifying the system structure because the antenna needs to be consistent with the carrier shape in some environments.Therefore,the research of multi-beam conformal array antenna is very urgent.This thesis aims to study the multi-beam conformal array antenna with simple structure,low loss and high performance.The main contents of this paper are as follows:First of all,the basic principles of Multi-Beam Antenna and its application background are introduced in detail.The main types of beamforming networks and their corresponding advantages and disadvantages are introduced.This thesis has made the detailed introduction to research background,domestic and international research dynamic.Secondly,the beamforming network based on passive microwave components is studied and analyzed.The number of phase shifters and couplers is reduced when the output amplitude and phase are consistent.This reduces the insertion loss of the network and improves the overall performance of the antenna system.In order to increase the number of beams without increasing the complexity of the network,this paper analyzes the beam direction of the antenna array when multiple ports are excited simultaneously and designs a multi-beam array antenna.Then,the above-designed multi-beam antenna is optimized.The group subarray is used to improve the space utilization of the antenna array.Two phase shifters are added to the beam forming network to improve the antenna array beam adjustability and the multi-beam array antenna has also been simulated and designed.Then,the beamforming network based on traveling wave array is studied and analyzed.A beam forming network is designed to effectively stimulate each unit.The symmetrical arrangement of the arrays makes the cross-polarization currents eliminate each other to solving the problem that the cross-polarization ratio is poor due to the radiation of the single-layer strip lines.So the radiation performance of the antenna array is optimized.In order to verify the accuracy of the analysis and simulation,real objects were processed and tested,and the actual measurement and simulation results were in good agreement.Finally,the application of conformal antenna is introduced.The effects of cylindrical carrier with different curvatures on the beamforming network and multi-beam array antennas are analyzed.At the same time,the antenna array is conformed to the missile,the results show that the multi-beam antenna array designed in this paper can still maintain stable performance under complex environments.