Bontae Koo

한국전자파학회논문지 (The Journal of Korean Institute of Electromagnetic Engineering and Science)

In multi-input multi-output (MIMO) pulse radar systems, precise pulse generation is critical for achieving high measurement resolution and detection accuracy in imaging and monitoring applications. This work presents a wide-range, tunable pulse generator for the pulse radar array system. The proposed pulse generator, based on a high-efficiency delay-locked loop (DLL) and a high-precision NOR-based edge combination scheme, offers a broad pulse-tuning range and minimal pulse-width error. Specifically, the DLL generates 41 anti-phased outputs, which are processed by the NOR gate with appropriate delay time and equal loading effects. A transmission-gate-based multiplexer selects the desired pulse without introducing systematic mismatch. Operating at a 50-MHz reference frequency, the prototype circuit achieves a wide tuning range from 142 ps to 7.04 ns (4957%). The proposed circuit demonstrates an rms jitter of 6 ps while consuming 2.8–3.2 mW from a 1 V power supply, depending on the selected pulse width.

한국전자파학회논문지 (The Journal of Korean Institute of Electromagnetic Engineering and Science)

Various short-range radars, such as impulse-radio ultra-wideband (IR-UWB) and frequency-modulated continuous-wave (FMCW) radars, are currently employed to monitor vital signs, including respiratory and cardiac rates (RRs and CRs). However, these methods do not consider the motion of an individual, which can distort the phase of the reflected signal, leading to inaccurate estimation of RR and CR because of a smeared spectrum. Therefore, motion compensation (MOCOM) is crucial for accurately estimating these vital rates. This paper proposes an efficient method incorporating MOCOM to estimate RR and CR with super-resolution accuracy. The proposed method effectively models the radar signal phase and compensates for motion. Additionally, applying the super-resolution technique to RR and CR separately further increases the estimation accuracy. Experimental results from the IR-UWB and FMCW radars demonstrate that the proposed method successfully estimates RRs and CRs even in the presence of body movement.

Various short-range radars, such as impulse-radio ultra-wideband (IR-UWB) and frequency-modulated continuous-wave (FMCW) radars, are currently employed to monitor vital signs, including respiratory and cardiac rates (RR and CR). However, these methods do not consider the motion of an individual, which can distort the phase of the reflected signal, leading to inaccurate estimation of RR and CR because of a smeared spectrum. Therefore, motion compensation (MOCOM) is crucial for accurately estimating these vital rates. This paper proposes an efficient method incorporating MOCOM to estimate RR and CR with super-resolution accuracy. The proposed method effectively models the radar signal phase and compensates for motion. Additionally, applying the super-resolution technique to RR and CR separately further increases the estimation accuracy. Experimental results from the IR-UWB and FMCW radars demonstrate that the proposed method successfully estimates RR and CR even in the presence of body movement.