Uncertainty Analysis And Structural Compensation For The Array Antennas Plane

The phased array antenna(PAA)is a typical structural electromagnetic thermal(SET)coupling system,and the functional surface of array antenna generally plays a key role in guaranteeing the effectiveness and reliability of the products.The antenna units will deviate from the initial position under the combined action of mechanical load and thermal load,which can lead to the deformation of array antennas plane and have a direct influence on the electromagnetic performance of PAA,such as beam pointing and gain,side lobe level(SLL),antenna efficiency,directivity.The theories and the methods for uncertainty measurements of complex functional surfaces will have positive effective on improving the reliability and the errors flow management of PAA,reducing the design cycles.The main work is as followed:1)The influence of structural distortions on the antenna EM performance is quantified.First this paper accomplishes the optimal mechanical design of the ridged horn antenna.Then six adjustment mechanisms are used to simulate the mechanical load and thermal load,such as wind and wave road.And the strain and stress response of the installing platform is obtained.Finally a coupled SET model of PAA is developed to obtain the strain and temperature field of the functional surface.By introducing the position deviation of radiating elements into antenna pattern functions,the degradation of EM performance is acquired.2)This paper proposes a surface accuracy compensation method for array antennas based on the SET model,which generates pre-deformation via structural adjustment before the operation of array antennas so as to minimize the gain loss caused by deformation in normal operation.A mathematic optimization model is built to calculate the optimal adjustment parameters and to maximize the tolerance of adjustment parameters through the coupled SET model.By combining the design tolerance index and the gain objective function,the optimization model can eventually be converted into a multi-objective optimization problem.Pareto solution can be given by adopting the existing multi-objective algorithms.In this way,the objective of improving the EM properties of array antennas,reducing the difficulty of installation as well as cutting down the manufacturing cost is achieved.Then the proposed approach can be enlarged and used to compensate the surface accuracy of PAA.3)The influence of the phase errors on antenna EM performance is analyzed based on the FEM model of microwave power amplifier link of transmit and receive modules.