Differential-Phase Radar with Amplitude-Compensated Complex Signal Demodulation for Vital Sign Detection

A differential-phase radar with amplitude-compensated complex signal demodulation (ACCSD) is presented., which can detect vital-signals from one-side of the human body even during back-and-forth random movements. Differential signal demodulation is achieved using the proposed ACCSD method. Compared with the conventional complex signal demodulation (CSD) method, the proposed method can avoid a distortion due to amplitude variations of baseband signal. Experiments also show that the proposed ACCSD provides the results identical to those of an extended differentiate and cross-multiply (DACM) method, while the processing time of the ACCSD is 10 times faster than that of the extended DACM.