DC coupled CW radar sensor using fine-tuning adaptive feedback loop

A new DC coupled continuous-wave (CW) radar sensor using a fine-tuning adaptive feedback loop technique to calibrate the DC offset is presented. This technique not only makes the radar sensor work with sufficient high gain at the DC-coupled baseband stage, but also allows it to detect movement with stationary moment. Experiments demonstrate that the proposed DC coupled radar sensor can completely relieve the baseband stages from saturation and retain all the desired DC information, while the conventional AC coupled radar sensor leads to significant signal distortion when a movement has stationary moment.