Envelope detection for a double-sideband Low IF CW radar

The requirement to detect weak physiology motion by Doppler radar arises new architectures utilizing low intermediate frequency (IF) to achieve high signal-to-noise ratio (SNR). With the help of low IF, the significant motion information is modulated to IF domain, promoting the system's resistivity to both noise impact and AC distortion. However, the requirement for simultaneously sampling IF outputs and IF carrier would waste more analog to digital converter (ADC) resources in a digitally assisted low IF system. In this paper, we propose a new method of envelope detection for a double-sideband low IF con-tinuous-wave (CW) radar without sampling the IF carrier. Together with the carrier compensation method realized in hardware, the motion information can be extracted with fewer ADC resources.