Scaled radar cross section measurements with terahertz-spectroscopy up to 800 GHz

Radar cross section measurements of complex, large objects (e.g. aircraft) are usually performed on miniaturized models, as this enables a well controllable measurement environment. The system frequency in the scaled scenario is proportional to the inverse size ratio of the model compared to the original object. If a high scaling factor is required to accommodate the measurement setup in a laboratory, the scaled frequencies can reach several hundred gigahertz, hardly accessible with today's network analyzers, especially when high frequency radar applications are concerned. Consequently, this paper discusses the feasibility and accuracy of terahertz spectroscopy, which allows accessing the frequency range of up to and even above 1 THz, for such measurements. In this initial study, radar cross section measurements of a perfectly conducting sphere and a metal plate are in good agreement with the theory up to 800 GHz, demonstrating the capability of the measurement setup.