Optimization Design Of Nulling Array Antenna

With the rapid development of satellite navigation and communication,the anti-jamming ability of wireless system has been widely concerned.Using nulling antenna is an important scheme to suppress directional electromagnetic interference.Nulling antenna includes single antenna and array antenna.In this thesis,the method of maximum power transmission efficiency(MMPTE)is used to design nulling array antenna,which can generate multi-nulling in the desired directions.The main research contents of this paper include:1.First,a one-dimensional nulling array antenna that works at 2.45 GHz is designed.The one-dimensional array antenna is composed of 8 rectangular patch antenna elements arranged linearly.By setting multiple virtual receiving antennas in the nulling azimuth,the power transmission equation between the transmitting array antenna and the receiving array antenna is constructed,and the minimum power transmission between the transmitting and receiving array antennas is optimized,and the array antenna excitation that generates multiple nulling beams is obtained distribution.In this paper,a 1-to-8 feed network design is used to realize multiple null-adjusted feeds for the array antenna.Numerical simulation and test results show that the one-dimensional nulling array antenna can form a single or multiple nulling beams in the main radiation direction,and the nulling depth can reach-20 d B.2.Then,in order to verify the versatility of the minimum power transmission method in the design of nulling array antennas,a planar nulling array antenna working at 3.4GHz was designed.The array antenna uses TLY-5 as the substrate material and is composed of 64 rectangular patch antenna elements.The feed network is composed of 8 8-port digitally controlled feed channels.In the same way,by setting up multiple receiving antennas,establishing a power transmission equation and optimizing the excitation distribution under the minimum power transmission condition,multiple nulling beams of the planar array antenna can be realized.Simulation and test results show that the planar nulling array antenna can form single and multiple nulling beams at the same time,and thus has better anti-interference and anti-interception capabilities.