Near/far-field transformation for two-dimensional metamaterials

In this paper, the near-to-far field transformation technique has been applied to predict the far-field information from the near-field measured data of metamaterials, which can be achieved by two-dimensional (2D) near-field microwave scanning apparatus (2D mapper). The 2D mapper is only near-field scanning system, and the far-field data cannot be obtained by this system directly. The near-to-far field transformation method has been studied to predict the far field from the known near-field information, which will make the 2D mapper more efficient. In order to demonstrate the correctness and the feasibility of the proposed method, we design a two-element array antenna, which consists of two infinite current filaments with the same magnitudes and opposite phases. The results from theoretical analysis and the prediction have been presented, which have excellent agreements. Finally, a metamaterial lens is designed, and the far-field radiation pattern is given with the near-field simulation data.