Extrapolation of truncated spherical near-field measurements

Truncation is a main issue of near-field antenna measurements. In many situations full coverage of the AUT's field is not possible mainly due to mounting limitations. A possible solution could be extrapolation. This paper presents and compares three different extrapolation techniques for truncated spherical near-field measurement data. It will be shown that the iterative method shows superior performance, even for complex antenna structures and measured data, compared to constant value extension methods. The iterative approach enhances measurement quality and reduces acquisition time.