Experimental characterization of scattering from the trihedral corner reflector in the E-band

Canonical objects with known radar cross section (RCS), for example, the trihedral corner reflector (TCR), play a crucial role in the calibration of automotive radar sensors. Moreover, these canonical objects are also used in the validation of simulated RCS obtained using asymptotic methods, such as hybrid geometric optics (GO) and the physical optics (PO) based methods. However, accurate RCS prediction with asymptotic methods is highly dependent on the individual scattering mechanisms considered in a simulation, for example reflection and diffraction from the TCR surfaces and edges, respectively. Reliable measurements are therefore required to evaluate if a particular interaction mechanism can be neglected to reduce computation complexity without adversely affecting the accuracy of the predicted RCS. In this letter, the monostatic scattering characteristics of three metallic TCRs are investigated with varying geometrical sizes in the E-band, that is, from 60 GHz to 90 GHz. The ultra-wideband (UWB) measurements, which offer a high delay resolution, can enable the identification of the individual scattering mechanisms. Diffraction from the TCR edges is experimentally demonstrated to contribute to a non-negligible scattered power in this frequency band.