Abstract: A multiple-target vital sign detector includes a self-injection-locked oscillator (SILO), a chirp up/down converter, a frequency demodulator and a multiple-target vital sign processor. The chirp up/down converter performs conversion from an oscillation signal generated by the SILO to a frequency-modulated continuous wave (FMCW) signal to detect an area and from a received FMCW signal reflected from the area to an injection signal, while the SILO is injected with the injection signal to enter a self-injection-locked state. The locations and vital signs of multiple subjects are extracted from the oscillation signal using the frequency demodulator and the multiple-target vital sign processor. The objective of using the SILO is to improve the sensitivity of the FMCW detection process so as to more effectively distinguish the vital signs of multiple subjects at different locations.

Abstract: A SIL monopulse radar includes a self-injection-locking oscillator (SILO), a transmit antenna, two receive antennas, a hybrid coupler, a first demodulator, a second demodulator and a processor. The transmit antenna transmits the oscillation signal of the SILO to object. The two receive antennas receive a reflected signal from the object as a first echo signal and a second echo signal. The hybrid coupler outputs a difference signal and a sum signal. The difference signal is injected into the SILO. The first demodulator frequency-demodulates the oscillation signal to produce a first demodulated signal. The second demodulator phase-demodulates the sum signal by using the oscillation signal as a reference signal to produce a second demodulated signal. The processor processes the first and second demodulated signals to produce a monopulse ratio signal. The SIL monopulse radar can identify the posture and motion of a human body by analyzing the monopulse ratio signal.

Abstract: A multiple-target vital sign detector includes a self-injection-locked oscillator (SILO), a chirp up/down converter, a frequency demodulator and a multiple-target vital sign processor. The chirp up/down converter performs conversion from an oscillation signal generated by the SILO to a frequency-modulated continuous wave (FMCW) signal to detect an area and from a received FMCW signal reflected from the area to an injection signal, while the SILO is injected with the injection signal to enter a self-injection-locked state. The locations and vital signs of multiple subjects are extracted from the oscillation signal using the frequency demodulator and the multiple-target vital sign processor. The objective of using the SILO is to improve the sensitivity of the FMCW detection process so as to more effectively distinguish the vital signs of multiple subjects at different locations.

Abstract: A 3-D path detection system includes an image capture device, a radar device and a computing module. The image capture device is provided to produce a dynamic image for calculating the x- and y-direction (transverse) pixel-value displacements according to a captured moving object image. The radar device is configured to transmit an input wireless signal to a moving object and receive a reflection signal from the moving object, and is configured to calculate a z-direction (longitudinal) displacement of the moving object according to a Doppler shift in the reflection signal. The computing module is configured to construct a 3-D path of the moving object according to the x- and y-direction pixel-value displacements of the moving object image and the z-direction displacement of the moving object.

Abstract: A vital sign detection system includes a radar device, a nonreciprocal network, a first antenna and a second antenna. An output signal from the radar device is delivered to the first antenna via the nonreciprocal network and then transmitted to a first side of a biological subject via the first antenna. A first reflection signal from the first side of the biological subject is received by the first antenna and then delivered to the second antenna via the nonreciprocal network and then transmitted to a second side of the biological subject via the second antenna. A second reflection signal from the second side of the biological subject is received by the second antenna and then delivered to the radar device via the nonreciprocal network for vital sign detection with random body movement cancellation.

Abstract: In non-contact pulse transit time measurement system of the present invention, two continuous-wave radars are provided to detect movements at two positions on a subject for use in measuring pulse transit time. The measurement of the pulse transit time can be continuous and last for a long time because there is no contact to skin necessary.

Abstract: A non-contact vital sign monitoring system transmits wireless signals to the same side of a biological subject via two antennas with different gains, and the two antennas receive two reflected signals from the biological subject with random body movement. Under a proper setup of the two antennas, the two reflected signals can be adjusted by an amplitude and phase adjusting unit to have the Doppler shift components caused by body movement with equal magnitude and out of phase and the Doppler shift components caused by vital signs with different magnitude. Therefore, the random body movement effect can be cancelled based on the relation between the two reflected signals in using the system to monitor the vital signs of the subject.

Abstract: A quadrature self-injection-locked radar utilizes a phase shifter to make a oscillation signal operating in two phase modes, and utilizes a frequency demodulator for frequency demodulation and a signal processor for signal processing to eliminate the nonlinear distortion caused by self-injection locked phenomenon. Therefore, the self-injection locked radar can be applied to more cases for detecting displacement variations with any range.

Abstract: A 3-D path detection system includes an image capture device, a radar device and a computing module. The image capture device is provided to produce a dynamic image for calculating the x- and y-direction (transverse) pixel-value displacements according to a captured moving object image. The radar device is configured to transmit an input wireless signal to a moving object and receive a reflection signal from the moving object, and is configured to calculate a z-direction (longitudinal) displacement of the moving object according to a Doppler shift in the reflection signal. The computing module is configured to construct a 3-D path of the moving object according to the x- and y-direction pixel-value displacements of the moving object image and the z-direction displacement of the moving object.

Abstract: A vital sign detection system includes a radar device, a nonreciprocal network, a first antenna and a second antenna. An output signal from the radar device is delivered to the first antenna via the nonreciprocal network and then transmitted to a first side of a biological subject via the first antenna. A first reflection signal from the first side of the biological subject is received by the first antenna and then delivered to the second antenna via the nonreciprocal network and then transmitted to a second side of the biological subject via the second antenna. A second reflection signal from the second side of the biological subject is received by the second antenna and then delivered to the radar device via the nonreciprocal network for vital sign detection with random body movement cancellation.

Abstract: A quadrature self-injection-locked radar utilizes a phase shifter to make a oscillation signal operating in two phase modes, and utilizes a frequency demodulator for frequency demodulation and a signal processor for signal processing to eliminate the nonlinear distortion caused by self-injection locked phenomenon. Therefore, the self-injection locked radar can be applied to more cases for detecting displacement variations with any range.

Abstract: A non-contact vital sign monitoring system transmits wireless signals to the same side of a biological subject via two antennas with different gains, and the two antennas receive two reflected signals from the biological subject with random body movement. Under a proper setup of the two antennas, the two reflected signals can be adjusted by an amplitude and phase adjusting unit to have the Doppler shift components caused by body movement with equal magnitude and out of phase and the Doppler shift components caused by vital signs with different magnitude. Therefore, the random body movement effect can be cancelled based on the relation between the two reflected signals in using the system to monitor the vital signs of the subject.