Motion/vibration detection system and method with self-injection locking

Patent metadata

Field	Value
Publication number	US-9603555-B2
Application number	US-201414154252-A
Country	US
Kind code	B2
Filing date	Jan 14, 2014
Priority date	May 17, 2010
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A motion/vibration detection system and method therefore are provided. The system includes a transmitter and a receiver. The transmitter includes a transmit/receive antenna unit and a first oscillator. The receiver includes a receiving unit and a demodulation unit. The transmit/receive antenna unit receives an output signal from the first oscillator and transmits a detection signal. The detection signal is reflected from at least one object under detection into a reflected detection signal, which is received by the transmit/receive antenna unit. The transmit/receive antenna unit injects the reflected detection signal into the first oscillator and accordingly the first oscillator is under a self-injection locking mode. The receiving unit receives the detection signal. The demodulation unit demodulates the detection signal received by the receiving unit into a baseband output signal, to extract at least one motion/vibration information of the objection under detection.

First claim

What is claimed is:

1. A motion/vibration detection system, comprising:
at least one transmitter, the at least one transmitter comprising a transmit/receive antenna unit and a first oscillator unit; and
at least one receiver, comprising a receiving unit and a demodulation unit; wherein,
the transmit/receive antenna unit is coupled to or electrically connected to a signal output port of the first oscillator unit, receives an output signal from the first oscillator unit and transmits a detection signal;
the detection signal is reflected from at least one object as a reflected detection signal, which is received by the transmit/receive antenna unit;
the transmit/receive antenna unit injects the reflected detection signal, as an injection signal, into the first oscillator unit and accordingly the first oscillator unit is under a self-injection locking mode;
the receiving unit is coupled to or electrically connected to the demodulation unit and receives the detection signal; and
the demodulation unit demodulates the detection signal received by the receiving unit into a baseband output signal, to extract at least one motion/vibration information of the at least one object.

2. The motion/vibration detection system of claim 1 , further comprising:
a processing unit, coupled to or electrically connected to the demodulation unit, for receiving the baseband output signal from the demodulation unit;
the processing unit processes the baseband output signal to extract the at least one motion/vibration information of the at least one object.

3. The motion/vibration detection system of claim 2 , wherein,
the processing unit performs digital band-pass filtering, amplifying, and analyzing a phase difference of the baseband output signal, and obtains a position information of the at least one object.

4. The motion/vibration detection system of claim 2 , wherein,
the processing unit performs digital low-pass filtering, amplifying, and Fourier-transform on the baseband output signal, and obtains time-domain waveforms and frequencies of the at least one motion/vibration information.

5. The motion/vibration detection system of claim 2 , wherein,
the processing unit receives a plurality of baseband output signals from a plurality of receivers, compares a phase difference of the plurality of baseband output signals, calculates arrival time differences of the plurality of receivers, and obtains a position of the at least one transmitter.

6. The motion/vibration detection system of claim 2 , wherein,
the at least one transmitter further comprises comprising a signal generation unit, which is coupled to or electrically connected to the first oscillator unit; and
the signal generation unit generates an analog control voltage waveform, and inputs the analog control voltage waveform into the first oscillator unit and the processing unit.

7. The motion/vibration detection system of claim 6 , wherein, the demodulation unit demodulates the detection signal into a voltage signal containing the analog control voltage waveform and the at least one motion/vibration information.

8. The motion/vibration detection system of claim 1 , further comprising:
a signal generation unit, coupled to or electrically connected to a voltage input port of the first oscillator unit.

9. The motion/vibration detection system of claim 1 , wherein the transmit/receive antenna unit comprises:
a first antenna, transmitting the detection signal, and receiving the reflected detection signal;
the first antenna is a single antenna or an antenna array.

10. The motion/vibration detection system of claim 1 , wherein the transmit/receive antenna unit comprises:
a first antenna, transmitting the detection signal; and
a second antenna, receiving the reflected detection signal;
each of the first antenna and the second antenna is a single antenna or an antenna array.

11. The motion/vibration detection system of claim 10 , wherein the receiving unit comprises:
a third antenna, receiving the detection signal;
the third antenna is a single antenna or an antenna array.

12. The motion/vibration detection system of claim 1 , wherein the first oscillator unit is an optical laser, and the transmit/receive antenna unit comprises:
an optical transmitting device, transmitting a laser output optical signal of the first oscillator unit as the detection signal; and
an optical receiving device, injecting the reflected detection signal into the first oscillator unit.

13. The motion/vibration detection system of claim 1 , wherein, the injection signal is injected into an injection signal input port of the first oscillator unit, and accordingly the first oscillator unit is under the self-injection locking mode.

14. The motion/vibration detection system of claim 1 , wherein, the injection signal is injected into one of a pair of differential signal output ports of the first oscillator unit, and accordingly the first oscillator unit is under the self-injection locking mode.

15. The motion/vibration detection system of claim 1 , wherein,
the injection signal is injected into a single-ended signal output port of the first oscillator unit, and accordingly the first oscillator unit is under the self-injection locking mode.

16. The motion/vibration detection system of claim 1 , wherein,
the detection signal and the reflected detection signal are both a radio frequency modulation signal.

17. The motion/vibration detection system of claim 1 , wherein, the demodulation unit comprises:
a second oscillator unit, a time delay unit, a mixer unit and a low-pass filter unit;
the receiving unit is coupled to or electrically connected to one input port of the second oscillator unit, injects the detection signal into the second oscillator unit, and accordingly the second oscillator unit is injection-locked by the detection signal;
two output ports of the second oscillator unit are coupled to or electrically connected to the time delay unit and the mixer unit, respectively;
two input ports of the mixer unit are coupled to or electrically connected to at least one of the two output ports of the second oscillator unit and an output port of the time delay unit, an output port of the mixer unit is coupled to or electrically connected to an input port of the low-pass filter unit;
the mixer unit and the time delay unit demodulate an output signal of the second oscillator unit; and
the low-pass filter unit filters out mixing spurious signals from an output signal of the mixer unit, and an output of the low-pass filter unit is the baseband output signal of the demodulation unit.

18. The motion/vibration detection system of claim 17 , wherein,
the output signal of the second oscillator unit is synchronous with the detection signal because of injection locking.

19. The motion/vibration detection system of claim 1 , wherein,
the demodulation unit comprises: an amplifier unit a mixer unit, a time delay unit and a low-pass filter unit;
the amplifier unit is coupled or electrically connected to the receiver unit;
the time delay unit is coupled or electrically connected to the amplifier unit;
two input ports of the mixer unit are coupled to or electrically connected to the amplifier unit and the time delay unit; and
the low-pass filter unit is coupled to or electrically connected to an output port of the mixer unit.

20. The motion/vibration detection system of claim 1 , wherein,
the demodulation unit comprises: a low noise amplifier unit, a first mixer unit, a second mixer un

Assignees

• Ind Tech Res Inst
• Nat Sun Yat-Sen Univ

Inventors

• Horng Tzyy-Sheng
• Wang fu-kang
• Peng Kang-Chun

Classifications

• A61B5/0816

  Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00) · CPC title

• A61B5/02416

  using photoplethysmograph signals, e.g. generated by infrared radiation (A61B5/14552 takes precedence) · CPC title

• A61B5/113 Primary

  occurring during breathing · CPC title

• A61B5/1102

  Ballistocardiography · CPC title

• A61B5/0059

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title