Simple Near-field to Far-field Transformation Method Using Antenna Array-factor

This paper presents a simple and practical method and measurement results of transformation by using the idea of array-factor for direct far-field prediction from the near-field data of antenna and RCS in cylindrical scanning system. When radiation pattern of an antenna or scattering pattern of radar cross-section (RCS) is measured, its characteristics is usually evaluated in the far-field area. However, measurement is usually done in the radio anechoic chamber to reduce unnecessary reflected wave and deviates from the condition of far-field according to the size or the measuring frequency. On the other hand, it is well known that methods such as compact-range or the transformation processing approach can transform the pick-up data from the near-field to the far-field. The measurement results by this simple near-field transformation agree very well with the conventional far region measurement method.