Experimental Analysis of VNA-based Measurement Errors in Mobile THz Applications

Terahertz (THz) measurement systems are crucial for the performance validation and testing of innovative designs and components to verify their reliability towards designated THz applications. This paper investigates the measurement uncertainty of THz measurement setup based on Vector Network Analyzer (VNA) with frequency extension modules. Our work focuses on the effects of equipment mobility and the accompanying radio-frequency (RF) cable flexure, which impact phase stability and measurement accuracy. The stability of THz VNA system is studied for four VNA extension setups at waveguide frequency bands from 75 GHz up to 1.5 THz. The upper bound of phase error caused by RF cable flexure is determined up to 330 GHz. The influence of the considered uncertainty is demonstrated by a degradation in the range accuracy and distortion in the image quality of a 2-D THz imaging scenario.