Efficient Frequency Domain Sampling Schemes for THz SAR Systems

This paper addresses efficient frequency domain sampling techniques for faster Terahertz (THz) synthetic aperture radar (SAR) imaging. While the large available absolute bandwidths in the frequency range beyond 100 GHz enable very high resolution imaging techniques, sampling times e.g. in stepped continuous wave systems increase due to the large number of samples. Of course, fast scanning can be achieved by larger frequency steps but this comes at the cost of a smaller unambiguous range accessible to the measurement system. Especially in case of complex targets that are to be imaged, this can be a challenge. We propose, compare and discuss different sampling schemes in the frequency domain with non-equidistant frequency steps. The discussion is validated by measurements using a vector network analyzer (VNA) SAR imaging setup operating between 260 GHz and 400 GHz.