Phase-Spacing Optimization of Linear Microstrip Antenna Arrays Using Simulation-Based Surrogate Superposition Models

摘要

A technique for simulation-driven optimization of the phase excitation tapersrnand spacings for linear arrays of microstrip patch antennas is presented. Our techniquernexploits two models of the array under optimization: an analytical model which is based onrnthe array factor, as well as an electromagnetic (EM) simulation-based surrogate model of thernentire array. The former is used to provide initial designs which meet the design requirementsrnimposed on the radiation response. The latter is used for tuning of the array radiationrnresponse while controlling the array reflection response as well as for validation of the finalrndesign. Furthermore, the simulation-based surrogate model allows for subsequent evaluationrnof the array responses in the beam scanning operation at negligible computational costs. Thernsimulation-based surrogate model is constructed with a superposition of simulated radiationrnand reflection responses of the array under design with only one radiator active at a time.rnLow computational cost of the surrogate model is ensured by the EM-simulation data computedrnwith coarse meshes. Reliability of the model is achieved by means of suitable correctionrncarried out with respect to the high-fidelity array model. The correction is performed iterativelyrnin the optimization process. Performance, numerical efficiency, and accuracy of therntechnique is demonstrated with radiation pattern synthesis of linear arrays comprising 32rnmicrostrip patch antennas by phase-spacing optimization. Properties of the optimal designs inrnthe beam scanning operation are then studied using the superposition models and comparedrnto suitably selected reference designs. The proposed technique is versatile as it also can bernapplied for simulation-based optimization of antenna arrays comprising other types of individuallyrnfed elements.