FMCW-CDMA Based Radar-Repeater Network for Enhanced Detection and 2D Imaging of Specular Targets

Detection of specular targets is a significant challenge for single-platform radar systems. The mirror-like reflections direct energy away from the radar receiver, reducing the signal-to-noise ratio (SNR) below the detection threshold. Distributed repeaters can effectively address this by increasing the virtual aperture size, which enhances spatial diversity and provides additional degrees of freedom. In this work, a 38–39 GHz Frequency-Modulated Continuous-Wave (FMCW) radar system with code-modulated distributed repeater architecture is designed to enhance detection capability. The implementation of code multiplexing enables the unique identification of repeater signals, even when the polarization of reflected signals changes. Simulations and measurements verify the independent separation of the repeater response and the experimental results show improved 2D imaging and accurate localization of a flat-plate specular target, validating the distributed coded-repeater-aided radar model.