A Reconstructing Method for Multifeed Large-Scale Antenna Array Pattern Measurement

A far-field pattern reconstructing method is proposed for the multifeed large-scale antenna arrays in this paper. When the radiation pattern of a large-scale array is measured in the far field, the measurement distance is extremely large. To reduce the measurement distance, the conventional near-field measurement technique utilizes the near-field-far-field transformation to calculate the far-field radiation pattern. In this paper, the far-field pattern of multifeed large-scale antenna array is reconstructed at a given distance in the Fresnel region. In other words, the field distribution at the given distance matches well with the desired far-field pattern and can be directly measured by the far-field measurement technique. The far-field pattern reconstruction is realized by exciting the array elements with a specific phase distribution. The excitation strategy is determined by the given measurement distance and the direction of the far-field radiation pattern. Both theoretical and full-wave simulations are utilized to validate the proposed method. The results show that the measurement distance can be effectively reduced by using the proposed method. It should be noted that the proposed method is only studied and validated for a uniformly spaced point source array. The array is excited in phase or with a progressive phase distribution.