Echo Reduction with Minimum Sampling in Spherical Near Field Measurements using Translated-SWE Algorithm

In Near Field (NF) measurements different echo reduction techniques can be applied to mitigate echoes or stray signals deriving from the surrounding environment [1-6]. A very promising echo reduction technique is based on the so called spatial or modal filtering [1]. The spatial filtering is very efficient in measurement scenarios with stationary AUT but necessitates an offset of the AUT in scenarios where the antenna is rotating [5-6]. Unfortunately, the measurement of the AUT in an offset configuration requires the acquisition of a higher number of samples [7-8]. An innovative spherical NF/FF transformation algorithm for offset measurements based on a Translated Spherical Wave Expansion (TSWE) has been recently proposed [9]. In this paper we investigate by experiment the echo reduction properties of offset AUT measurements using TSWE.