Accurate Characterization of Layered Material with Broadband Sub-Terahertz Imaging

Compared with other imaging technologies, terahertz (THz) waves offer a unique balance between spatial resolution and penetration depth. Broadband electronic sub-THz imaging is particularly promising for applications that require multi-dimensional resolution, small footprints, and cost efficiency. It is especially important to measure electrical properties (permittivity and conductivity) accurately for material characterization and non-destructive testing. In this paper, we demonstrate a sub-THz imaging technique for characterization of multi-layer materials. Based on experimental results, a modified measurement model can provide higher permittivity measurement accuracy than the conventional free-space method.