Accuracy Analysis of Group Delay Variation Measurement in Anechoic Chambers: Analysis and accuracy improvement through time-gating techniques

Precise global navigation satellite systems (GNSS) antenna characterization is needed in several applications, targeting high-accuracy positioning and timing. In fact, antennas introduce errors in the phase and delay experienced by GNSS signals on their way to the receiver. Such errors are described by phase center variations and group delay variations (GDVs). While today the characterization of phase center variations is canonically established, the measurement of GDVs is still a matter of research for its high requirements in terms of measurement accuracy. This article provides an analysis of the accuracy performance achievable in anechoic chambers, estimating the uncertainty in the GDV produced by imperfections of the measurement system itself, and proposes a possible countermeasure to be applied.