A 28-nm 9-mm High-Resolution Multi-Mode IR-UWB Radar SoC with 16-GS/s Equivalent-Time Sampling for Non-Contact Detection of Human Vital Signs

This paper presents a 9-mm high-resolution multi-mode impulse radio ultra-wideband (IR-UWB) radar system on chip (SoC) for the non-contact detection of human vital signs. It incorporates a radio-frequency front-end transceiver, a 4-GS/s 8-channel time-interleaved analog-to-digital converter, a 4-phase clock generator, and a digital part. The proposed all-digital transmitter has two operation modes, namely, a voltage control delay line (VCDL) mode and a modulated pulse mode. For alignment in the equivalent time sampling (ETS) mode, an on-chip IR-UWB state machine is devised to control the IR-UWB SoC operation. The IR-UWB chip is prototyped in a 28-nm CMOS process. A clear walk pathway of up to 3.75 m is measured in the VCDL mode. A maximum detection range of 10 m is tested in the 1-bit modulated pulse mode and a range of up to 12 m is measured under the 5-bit barker code modulated pulse mode. Clear breath detection is executed in the ETS mode at a detection distance of 2.5 m. The total area of the chip is $1.08 \times 1.125 \mathrm{~mm}^{2}$.