Microwave motion sensor

• US 9,448,053 B2
• Filed: 04/19/2013
• Issued: 09/20/2016
• Est. Priority Date: 09/20/2010
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Jau, Je-Kuan, Wu, Ping-Hsun
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): Alejnikov, Jr., Robert P
• Application Number:
  US13/866,115
• Publication Number:
  US 20130234729A1
• Time in Patent Office: 1,250 Days
• Field of Search: 324/642
• US Class Current: 1/1
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: G01B 7/14 for measuring distance or clearance between spaced objects or spaced apertures G01B7/30 takes precedence
• CPC Class Codes: G01S 13/583 using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
• CPC Class Codes: G01S 13/88 Radar or analogous systems specially adapted for specific applications electromagnetic prospecting or detecting of objects, e.g. near-field detection, G01V3/00
• CPC Class Codes: G08B 13/2491 Intrusion detection systems, i.e. where the body of an intruder causes the interference with the electromagnetic field

Abstract

A microwave motion sensor including a transmitting device, a signal processing device, a signal processing device, and a path switching device is disclosed. The transmitting device transmits a microwave signal to a space under detection. The receiving device receives a reflected microwave signal reflected from the space under detection. The signal processing device processes the reflected microwave signal received by the receiving device to judge whether there is a disturbance in the space under detection, wherein the signal processing device generates the microwave signal. The path switching device is coupled to the signal processing device and the transmitting device and results in different phase shifts to a plurality of transmission paths travelled by the microwave signal.

Claims

1. A microwave motion sensor, comprising:

a transmitting device transmitting a microwave signal to a space under detection;

a receiving device receiving a reflected microwave signal reflected from the space under detection;

a signal processing device processing the reflected microwave signal received by the receiving device to judge whether there is a disturbance in the space under detection, wherein the signal processing device generates the microwave signal; and

a delay path switching device coupled to the signal processing device and the transmitting device, wherein the delay path switching device switches a plurality of transmission paths having different delays and results in different phase shifts to the transmission paths which the microwave signal passes through,

wherein,

the signal processing device at least comprises a dual-control voltage-controlled oscillator, which generates the microwave signal;

the signal processing device compares the microwave signal with a reference signal to obtain a first control voltage, which reflects an external disturbance information of the space under detection;

an oscillation frequency of the dual-control voltage-controlled oscillator is determined by the first control voltage and a second control voltage; and

wherein, in response to the dual-control voltage-controlled oscillator being affected by the external disturbance information and results in a DC offset to the first control voltage, the signal processing device generates a second voltage variation of the second control voltage according to a first voltage variation of the first control voltage to eliminate the DC offset of the first control voltage by the dual-control voltage-controlled oscillator.

2. The microwave motion sensor according to claim 1, wherein, a plurality of sensing zero points in these transmission paths are not overlapped with each other.

3. The microwave motion sensor according to claim 1, further comprising a delay path switching controller coupled to the delay path switching device to select one of these transmission paths.

4. The microwave motion sensor according to claim 3, wherein, the delay path switching controller turns off these transmission paths having different delays at non-sampling time periods.

5. The microwave motion sensor according to claim 1, wherein, the delay path switching device includes a delay unit, and at least two switches.

6. A microwave motion sensor, comprising:

a transmitting device transmitting a microwave signal to a space under detection;

a receiving device receiving a reflected microwave signal reflected from the space under detection;

a delay path switching device coupled to the receiving device, wherein the delay path switching device switches a plurality of reception paths having different delays and results in different phase shifts to the reception paths which the reflected microwave signal passes through; and

a signal processing device processing the reflected microwave signal received by the receiving device to judge whether there is a disturbance in the space under detection, wherein the signal processing device generates the microwave signal,

wherein,

the signal processing device at least comprises a dual-control voltage-controlled oscillator, which generates the microwave signal;

the signal processing device compares the microwave signal with a reference signal to obtain a first control voltage, which reflects an external disturbance information of the space under detection;

an oscillation frequency of the dual-control voltage-controlled oscillator is determined by the first control voltage and a second control voltage; and

wherein, in response to the dual-control voltage-controlled oscillator being affected by the external disturbance information and results in a DC offset to the first control voltage, the signal processing device generates a second voltage variation of the second control voltage according to a first voltage variation of the first control voltage to eliminate the DC offset of the first control voltage by the dual-control voltage-controlled oscillator.

7. The microwave motion sensor according to claim 6, wherein, a plurality of sensing zero points in these reception paths are not overlapped with each other.

8. The microwave motion sensor according to claim 6, further comprising a delay path switching controller coupled to the delay path switching device to select one of these reception paths.

9. The microwave motion sensor according to claim 6, wherein, the delay path switching device includes a delay unit, and at least two switches.

10. A microwave motion sensor, comprising:

a transceiving device, transmitting a microwave signal to a space under detection and receiving a reflected microwave signal reflected from the space under detection;

a signal processing device processing the reflected microwave signal received by the transceiving device to judge whether there is a disturbance in the space under detection, wherein the signal processing device generates the microwave signal; and

a delay path switching device coupled to the signal processing device and the transceiving device, wherein the delay path switching device switches a plurality of paths having different delays and results in different phase shifts to the paths which the microwave signal and the reflected microwave signal pass through,

wherein,

the signal processing device at least comprises a dual-control voltage-controlled oscillator, which generates the microwave signal;

the signal processing device compares the microwave signal with a reference signal to obtain a first control voltage, which reflects an external disturbance information of the space under detection;

an oscillation frequency of the dual-control voltage-controlled oscillator is determined by the first control voltage and a second control voltage; and

wherein, in response to the dual-control voltage-controlled oscillator being affected by the external disturbance information and results in a DC offset to the first control voltage, the signal processing device generates a second voltage variation of the second control voltage according to a first voltage variation of the first control voltage to eliminate the DC offset of the first control voltage by the dual-control voltage-controlled oscillator.

11. The microwave motion sensor according to claim 10, wherein, a plurality of sensing zero points in these paths are not overlapped with each other.

12. The microwave motion sensor according to claim 10, further comprising a delay path switching controller coupled to the delay path switching device to select one of these paths.

13. The microwave motion sensor according to claim 12, wherein, the delay path switching controller turns off these paths having different delays at non-sampling time periods.

14. The microwave motion sensor according to claim 10, wherein, the delay path switching device includes a delay unit, and at least two switches.