Abstract: Human vital signs (e.g. respiration and heartbeat) detection using radar is significant in many fields. The radar may fail to detect the human subjects at longer ranges if the radar is in line with multiple human subjects. To handle this, the paper proposes a new radar layout scheme, and distinguishes multiple human subjects from the range domain using high-resolution mmWave radars. This paper also integrates various methods to distinguish human subjects and stationary clutters. In this paper, the procedure of signal processing of FMCW mmWave radar is derived in detail and experimentally verified. The experimental results show that the proposed scheme in this paper can effectively distinguish human targets from stationary clutter and accurately extract multi-target respiratory rates. In addition, this paper discusses in detail the spatial blind areas of the proposed scheme under various radar numbers and spatial deployment schemes, and demonstrates that one can completely eliminate the spatial blind areas by using three noncollinear radars.