Reduced-Order Maximum Determinant Sampling Grids by Acquisition of Additional Arbitrary Sampling Points on an Optimized Path

A maximum determinant sampling grid (MDSG) presents a fully determinant non-redundant sampling grid for spherical near-field antenna measurements which can be efficiently measured using robot-based antenna measurement systems. Although the position of the sampling points is determined by the sampling grid, the sequence of data acquisition can still be optimized to reduce measurement time. A new trajectory optimization approach is proposed which reduces sharp curves in the path at the cost of a longer total path length. It is shown that this approach significantly increases the average path speed and reduces the measurement time compared to an optimization for the shortest path. Furthermore, the acquisition of additional sampling points on the resulting the path is investigated, allowing for lower-order MDSGs without sacrificing accuracy of the transformation results. As a result, this combination would allow to reduce the measurement time by almost 60 % compared to conventional equiangular measurements.