Far-field Beam Synthesis Using Near-field Measurement

Abstract

Recently, millimeter wave array antennas are actively researched for use in commercial applications, such as 5G mobile communications and vehicle radar. In such applications, the antennas are often required to scan their beams. Because the radiation patterns need to be measured to evaluate the performance of the formed beams and because there can be many beam combinations, it takes significant time to fully measure the performance of the antenna. One method of reducing the measurement time is to measure the radiation patterns of individual element and synthesize the total radiation pattern of the array antenna. With this approach, the formed beams can be obtained by properly weighting the element radiation patterns. The weights are proportional to the amplitudes and phases of the signals that are fed to the individual elements. In this paper, we introduce the radiation synthesis method based on the measurement performed in the near field.