This article proposes a single-conversion stepped-frequency continuous-wave (SCSFCW) radar that combines (SFCW) and self-injection-locked (SIL) to benefit from the range resolution Doppler sensitivity of two radars. An 8.5-9.5-GHz prototype SCSFCW system comprises subharmonic up/down converter with 3-3.5-GHz stepped chirp local-oscillator (LO) signal 2.5-GHz SIL IF was developed monitor vital signs, i.e., respiration rate (RR) heart (HR), multiple humans. The coherence were significantly...

This article presents the combination of a self-injection-locked (SIL) radar with frequency-modulated continuous-wave (FMCW) and switched phased-array (SPA) techniques to locate multiple people detect their vital signs high resolution sensitivity. The proposed system utilizes subharmonic upconverter/downconverter 1.675-2.175-GHz chirp local oscillator (LO) signal convert between 2.45-GHz SIL IF 5.8-6.8-GHz FMCW RF signal. It transmits receives echo using transmit (Tx) antenna receive (Rx)...

This article presents a novel monopulse radar that combines high-sensitivity continuous-wave (CW) and self-injection-locking (SIL) receivers to detect localize the movements in human body. The proposed utilizes CW sum pattern an SIL difference process echo signal from target, so it can produce ratio estimate angle of arrival (AoA) signal. With this capability, on target's chest are caused by vital signs such as respiration heartbeat for posture classification. In addition, be used fall alarm...

This work presents a novel scheme for 4-dimensional (D) frequency modulated continuous wave (FMCW) LiDAR, which demonstrates an unprecedentedly high velocity sensitivity. is achieved by utilizing the driving waveform to minimize phase noise originating from distributed feedback (DFB) laser during wavelength sweeping process on transmitting side, while receiving end, we use combination of self-injection-locked oscillator (SILO) and avalanche photodiode (APD) with cascaded multiplication...

This paper aims to design a tag antenna with metasurfaces for use in wearable vital-sign sensing system. The system is based on bistatic self-injection-locked (SIL) radar that consists of chest-worn SIL oscillator (SILO) and wireless handheld receiver. A frequency selective surface (FSS) an electromagnetic bandgap (EBG) are placed the front back side reduce influence moving clutter body proximity, respectively, In experiment, 5.8 GHz prototype was implemented proposed monitor vital signs...

This article presents a chest-worn device for monitoring the heart rate variability (HRV) of person in motion without direct contact with skin. The operates at 5.8 GHz and mainly consists self-injection-locked oscillator (SILO) tag antenna. transmits output signal an SILO that is frequency-modulated (FM) by Doppler effect physiological movement chest via antenna to remote FM receiver. Accordingly, heartbeat detected HRV can be estimated. comprises circularly polarized ring slot split-ring...

This paper presents a single conversion stepped-frequency continuous-wave (SCSFCW) radar that uses self-injection-locking technology to achieve high sensitivity, Doppler resolution and range resolution. Moreover, the is capable of extracting tiny shifts from different bins, so it has great potential monitor vital signs multiple people simultaneously. In experiment, 7.95-8.95 GHz SCSFCW prototype was constructed by an RF up-down converter pumped with 5.5-6.5 stepped chirp signal 2.45 IF...

This paper presents a 5.8 GHz wireless chest-worn sensor for monitoring heart rate variability (HRV). The consists of self-injection-locked oscillator (SILO) and tag antenna. It transmits radio-frequency (RF) signal that is frequency-modulated based on self-injection-locking by the physiological motion chest to handheld receiver demodulation analyze HRV. antenna stacked structure composed complementary slot ring resonator (CSRR) circularly polarized (CP) radiator, playing important roles as...

A 4-D FMCW LiDAR is demonstrated. In comparison to the traditional p-i-n PD in its receiver-side, cascaded M-layers APDs provide a better quality of images with unprecedented high velocity- sensitivity (5µm/sec) for slow-moving objects.

This paper presents a switched phased-array (SPA) radar that uses self-injection-locking (SIL) and digital beamforming (DBF) technologies to provide high sensitivity of vital sign detection accurate azimuthal tracking mobile person. Advantageously, the complexity RF transmission reception in proposed SPA is very low compared conventional phased array radar. In experiment, prototype SPA-SIL was implemented operate 2.4 GHz ISM band. can automatically track azimuth angle subject successfully...

This paper presents a transmitarray lens that can be worn on the chest to focus radar beam towards specific area of heart for monitoring rate variability (HRV). The used Doppler is based self-injection-locking (SIL) technology and was placed remotely from monitored subject. In experiment, set up concentrate incident wave penetrating into heart's tricuspid valve; thus, accuracy HRV greatly improved. comparison interbeat interval (IBI) data between proposed measurement conventional...

This study presents a see-through-wall (STW) life detector using self-injection-locked (SIL) technology. The SIL radar is operated at 433 MHz ISM band to achieve excellent penetration capability and coverage. Moreover, an additional phase shifter utilized eliminate the large frequency shift, which caused by strong clutter signals often causes mechanism fail. output signal of oscillator (SILO) passes sequentially through quintupler, amplifier, 2165 injection-locked (ILO) increase modulation...

This paper presents a 5.8 GHz low-IF Doppler radar that uses digital self-injection-Iocking (DSIL) technology to achieve high sensitivity and linearity. The system consists of an RF up-down converter, IF image rejector, DSIL radar. To verify its linearity, experiment the proposed was conducted detect slightly vibrating object moved over large range by two stacked actuators, showing satisfactory promising results.

Free-form lenses are commonly used for controlling the ray direction of LEDs, particularly when a uniform lighting distribution sensor applications is required.We propose target grid modification (TGM) method based on Snell's law, edge principle, and luminous flux mapping technique to facilitate design an LED free-form lens with illuminance properties over rectangular area.In proposed method, size grids plane adjusted adaptively in such way as improve uniformity distribution.It shown that...

This paper presents a low-IF Doppler radar that can measure the displacement of moving target with high sensitivity and linearity. The consists an RF front-end, IF transceiver, digital delay- self-injection-locking (DSIL) block, operating at fixed frequency 5.8 GHz 40 kHz, respectively, function well in highly cluttered environment help clutter canceller. In performance test experiments, identify vibration stationary constant-velocity object minimum peak-to-peak 100 μm, respectively....

This article presents a time-division multiplexing (TDM) multiple-input–multiple-output (MIMO) radar system that differs from existing ones by incorporating heterodyne self-injection-locking (HSIL) architecture for enhanced Doppler sensitivity. The operates in the unlicensed 6-GHz band and produces 3-D images of multiple individuals, enabling identification hotspot on person’s chest where maximum echo amplitude occurs. approach allows accurate reliable measurement vital signs, despite...

This paper presents a chest-worn oscillator tag for monitoring the heart health of an exercising person without direct contact with skin. The operates at 5.8 GHz based on self-injection-locking (SIL) Doppler radar principle and consists mainly antenna. For validation, system was developed proposed to detect cardiac intervals wearer who performs various activities including walking running. results thus obtained agree closely electrocardiogram (ECG) measurements.