A Quasi-optical THz Imaging System Using a One-port Vector Network Analyser

In this paper we demonstrate a simple single-pixel quasi-optical imaging setup with a one-port 140 GHz-220 GHz vector network analyser (VNA), a pyramidal horn antenna, a plano-convex lens and an X-Y translation stage. By placing an object at the focal plane of the lens and measuring its one-port S-parameters while scanning the object fixed onto the X-Y translation stage, 2D images of the object are constructed using S-parameter magnitude and phase information. The results show that the phase constructed image is better than magnitude constructed image in some cases. This finding indicates that VNA can be useful in THz imaging as it provides more information from the perspective of phase which can be used to enhance imaging.