Continuous-wave field disturbance sensing system

• US 8,089,394 B2
• Filed: 11/02/2009
• Issued: 01/03/2012
• Est. Priority Date: 11/02/2009
• Status: Active Grant

• Current Assignee: Invention Planet, LLC
• Original Assignee: Invention Planet, LLC
• Inventors: Stewart, Christopher E., Moulton, Grant E., Goody, Steven H.
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): BYTHROW, PETER M
• Application Number:
  US12/590,116
• Publication Number:
  US 20110102241A1
• Time in Patent Office: 792 Days
• Field of Search: 342/104, 342/105, 342/115, 342/175
• US Class Current: 342/104
• 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 7/034 Duplexers switching devices for waveguides H01P1/10; transmit-receive switching in transceivers H04B1/44
• CPC Class Codes: G01S 7/358 using I/Q processing
• CPC Class Codes: H01P 5/222 180° rat race hybrid rings
• CPC Class Codes: H01Q 21/065 Patch antenna array

Abstract

A field disturbance sensing system has an antenna, an oscillator producing a high-frequency signal, a first detector circuit, a second detector circuit, a combining network configured to couple the high-frequency signal to the antenna, and to couple the high-frequency signal and a reflected high-frequency signal to the first detector and to the second detector. An algebraic combining network sums a first detected signal having first detected high-frequency signal and a first detected reflected signal from the first detector circuit and a second detected signal having second detected high-frequency signal and a second detected reflected signal from the second detector circuit to produce a detected output signal. The first detected reflected signal is added to the second detected reflected signal and the first detected high-frequency signal is subtracted from the second detected high-frequency signal. A controller configured to convert the detected output signal to a speed between the antenna and a target.

Claims

1. A field disturbance sensing system comprising:

an antenna;

an oscillator producing a high-frequency signal;

a first detector circuit;

a second detector circuit;

a combining network configured to couple the high-frequency signal to the antenna, and to couple the high-frequency signal and a reflected high-frequency signal to the first detector and to the second detector;

an algebraic summing network summing a first detected signal having first detected high-frequency signal and a first detected reflected signal from the first detector circuit and a second detected signal having second detected high-frequency signal and a second detected reflected signal from the second detector circuit to produce a detected output signal wherein the first detected reflected signal is added to the second detected reflected signal and the first detected high-frequency signal is subtracted from the second detected high-frequency signal; and

a controller configured to convert the detected output signal to a speed between the antenna and a target.

2. The field disturbance sensing system of claim 1 further comprising a battery providing electric power to the field disturbance system.

3. The field disturbance sensing system of claim 1 further comprising an electronic display screen configured to display the speed to a user.

4. The field disturbance sensing system of claim 1 further comprising

a battery providing electric power to the field disturbance system;

an electronic display screen configured, to display the speed to a user; and

a housing incorporating the field disturbance sensing system of claim 1, the battery, and the electronic display screen so as to provide a hand-held field disturbance system.

5. The field disturbance sensing system of claim 4 wherein the hand-held field disturbance sensing system is a hand-held continuous wave radar system.

6. The field disturbance sensing system of claim 1 wherein the oscillator is a dielectric stabilized oscillator.

7. The field disturbance sensing system of claim 1 wherein the, antenna is a patch antenna defined on a first side of a printed circuit board and the oscillator is defined on a second side of the printed circuit board.

8. The field disturbance sensing system of claim 7 wherein the printed circuit board has a polytetrafluoroethylene-based substrate with metal-foil traces on the first side and on the second side.

9. The field disturbance sensing system of claim 7 wherein the printed circuit board has an epoxy-fiberglass composite substrate with metal traces on the first side and on the second side.

10. The field disturbance sensing system of claim 7 wherein the first detector circuit and the second detector circuit are defined on the first side of the printed circuit board.

11. The field disturbance sensing system of claim 10 wherein the combining network includes a first ring coupler and a second ring coupler defined on the first side of the printed circuit board, the first ring coupler having an LO input port connected to the oscillator, an antenna port connected to the antenna, an RF port connected to the second ring coupler at an RF input port, and an LO port connected to the second ring coupler at a second LO input port.

12. The field disturbance sensing system of claim 11 wherein the LO input port is separated from the LO port by a quarter wavelength distance around the first ring coupler in a first direction, and is separated from the antenna port by a second quarter wavelength distance around the first ring coupler in a second direction, and is separated from the RF port by a half wavelength distance around the first ring coupler.

13. The field disturbance sensing system of claim 12 where the RF input port is separated from the second LO input port a first distance around the second ring coupler in a third direction and a second distance around the second ring coupler in a fourth direction, the difference between the first distance and the second distance being an integer multiple of a half wavelength distance, the second ring coupler further comprising a first detector port a third distance from the second LO input port in the third direction and a second detector port the third distance from the second LO input port in the fourth direction.

14. The field disturbance sensing system of claim 13 wherein the third distance is an odd integer multiple of a quarter wavelength distance.

15. The field disturbance sensing system of claim 1 further comprising a second antenna coupled to the combining network, wherein the antenna transmits the high-frequency signal at the target and the second antenna receives the reflected high-frequency signal from the target.

16. The field disturbance sensing system of claim 15 further comprising an amplifier between the second antenna and the combining network.

17. The field disturbance sensing system of claim 1 wherein the antenna transmits the high-frequency signal at the target and the antenna receives the reflected high-frequency signal from the target.

18. The field disturbance sensing system of claim 1 further comprising

an amplitude modulation (“

AM”

) noise source configured to selectively produce AM noise on the high-frequency signal; and

a noise calibration circuit configured to achieve a minimum AM noise on the detected output signal when the selected AM noise is produced on the high-frequency signal.