Radar Cross-Section Characterization of the Car In-Cabin Environment at Sub-THz Frequencies

Paper in proceeding, 2022

Radar sensors at sub-THz frequencies (100 - 330 GHz) can potentially be used in car in-cabin monitoring systems. In designing such sensors, knowledge of the in-cabin propagation conditions at the sub-THz bands is useful. Considering the rather novel use-case, such data is not readily available and must be gathered through measurements. This paper presents a Radar Cross-Section (RCS) imaging system, which has been developed in order to characterize the reflective properties of common car in-cabin objects at 243 GHz. The system produces two types of data, RCS profiles and Inverse Synthetic Aperture Radar (ISAR) images, which can be analyzed jointly to give an intuitive and detailed view of object reflectivity. The system applies range-domain processing and prove efficient in ignoring peripheral reflection points and multipath, which allows for conducting compact measurements in an enclosed lab environment. The ISAR images achieve 1-2 centimeter spatial resolution, and thus demonstrates the fine-resolution capabilities of sub-THz radar systems.