Investigation of Stray Reflections in an Anechoic Chamber with Imaging Technique

The purpose of the work was to visualize the stray reflections in a large anechoic chamber. To assess the influence of multiple reflections caused by imperfect chamber design, a mathematical model of an idealized measurement procedure was developed. The novelty of the proposed study lies in usage of special diagrams that visualize the picture of measured distortions, which makes it possible to identify the most critical zones in terms of introduced errors within working area. All experiments were carried out with scanning, where the source antenna, representing the target, was moved on a plane relative to the receiving antenna that was tracking it. The obtained results reliably show the amplitude and phase errors over wide frequency band that manifest during measurements and are caused by stray reflections in the chamber. Imaging technique can become the basis for developing an error compensation scheme and improving the accuracy of testing process.