The objective of this paper is to provide some guidelines about the measurement uncertainty of Spherical Near Field (SNF) ranges when they are used to derive near field figure of merits instead of more conventional far field-based metrics.
One of the main advantages of the SNF ranges is their flexibility. Indeed, from the NF scanning, the spherical wave expansion is applied, and it can be used as a powerful, accurate and efficient propagation tool, able to evaluate figures of merits at (almost) any distance from the device under test. This feature is particularly
useful in the testing of modern antenna systems intended to operate in specific regions of space instead of conventional far field scenarios. Examples are Plane Wave Generators (PWG) which create a uniform field distribution in the proximity of the device, or more generic field synthesizer devices.
Despite the flexibility of SNF systems, the evaluation of their uncertainty budgets is normally limited to far field-based metrics. Understanding under which conditions and in which measurement scenarios such uncertainty budgets are applicable to more generic near field metrics is the main topic addressed in this paper.
