Repeater-Aided Millimeter-Wave Mimo Radar for Improved Detection of Specular Targets

Radar detection of specular targets is challenging, as targets reflect incident electromagnetic signals in specific directions based on the angle of incidence, and reflected energy is not directed at the receiver. A distributed repeater can help to retransmit this energy back to the receiver. Radar cross-sections also change for different target orientations, making detection even more challenging. This paper proposes using multiple transmit-repeat-receive combinations to enhance detection capabilities in the presence of changes in the target position and orientation. Increasing the number of transmitters and radar repeaters provides additional degrees of freedom and ensures robust target detection. Multiple-input and multiple-output (MIMO) millimeter-wave (mmWave) radar with distributed repeaters can address specular reflections from arbitrarily placed targets. A repeater-aided <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$36-38 \text{GHz}$</tex> MIMO mmWave radar is presented in this work, showing the improvement in detection for different target orientations.