Electromagnetic detection and imaging transceiver (EDIT) and roadway traffic detection system

• US 9,024,802 B2
• Filed: 04/13/2013
• Issued: 05/05/2015
• Est. Priority Date: 04/13/2013
• Status: Expired due to Fees

• Current Assignee: Stolar Incorporated
• Original Assignee: Stolar Incorporated
• Inventors: Stolarczyk, Larry G.
• Primary Examiner(s): Sotomayor, John B
• Application Number:
  US13/862,379
• Publication Number:
  US 20140306839A1
• Time in Patent Office: 752 Days
• Field of Search: 342/22, 342/27, 342/28, 342/114, 342/175, 342/179
• US Class Current: 342/22
• CPC Class Codes: G01S 13/40 wherein the frequency of transmitted signal is adjusted to give a predetermined phase relationship
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

An automatic frequency control is used to keep a continuous wave (CW) transmission tuned to the resonant frequency of a resonant microwave patch antenna (RMPA). Changes in loading and the bulk dielectric constant of the mixed media in front of the RMPA will affect its resonant frequency and input impedance. A significant shift in the measured input impedance is interpreted as an object moving nearby, and the phase angle of the measured input impedance is used to estimate the direction of an object'"'"'s movement.

Claims

1. An object detection system, comprising:

a resonant microwave patch antenna (RMPA) with an active face characterized by responses in its complex input impedance (Z_in) and resonant frequency to relative changes in the bulk dielectric constant loading caused by a movement of objects proximate to said active face, wherein the RMPA reacts differently to dielectric changes in its fringing and propagating e-fields according to relative direction;

an automatic control configured to minimize the Z_in of the RMPA while a continuous wave (CW) drive is applied to the RMPA by maintaining a state of resonance despite any media variations and movements of said objects proximate to said active face; and

an interpretive device for measuring and interpreting shifts in the input impedances and the phase angles of the RMPA as indications of the sizes, positions, and speeds of objects-of-interest relative to the face of the RMPA.

2. The object detection system of claim 1, further comprising:

a varactor connected to RMPA in such a way that the resonant frequency of the RMPA can be trimmed by a control voltage.

3. A roadway traffic detection system, comprising:

a resonant microstrip patch antenna (RMPA) configured to be buried and hidden in a roadway, wherein the RMPA reacts differently to dielectric changes in its fringing and propagating e-fields according to relative direction of objects above its active face;

a sensor controller connected to the RMPA to drive the RMPA with a variable frequency, and to measure the impedance and phase (Z_in) of the RMPA while keeping the RMPA at frequency resonance; and

an interpretive device that deduces particular changes in the resonant frequency, impedance, and phase of the RMPA as the size, direction, and speed of objects passing overhead;

wherein, objects near the RMPA affect the dielectric constant and thereby also affect the resonant frequency, impedance, and phase of the RMPA.

4. The roadway traffic detection system of claim 3, wherein a phase change is indicative of an angle relative to the RMPA, and a delta frequency and impedance change indicates the size and proximity to the RMPA.

5. The roadway traffic detection system of claim 4, further comprising:

a threshold detector to screen out any false positives;

wherein, an interpretation of changes in resonant frequency, impedance, or phase of Z_in, is output to annunciate the locating of a tunnel.

6. The roadway traffic detection system of claim 3, further comprising:

a device for using angle information with tomographic calculations to improve object detection and location by increasing the number of data points contributing to each analysis.

7. A method for detecting movements of objects, comprising:

radiating an area with a resonant microwave patch antenna (RMPA);

maintaining the frequency of a continuous wave (CW) transmission applied to the RMPA in real-time to match the resonant frequency of the RMPA as it changes with variations in its loading;

interpreting a minimum in the instantaneous input impedance of the RMPA as an indication of its being operated at its resonant frequency given how it is loaded; and

announcing the presence of objects moving nearby by analyzing how the instantaneous input impedance of the RMPA changes over time.

8. The method of claim 7, further comprising:

announcing the relative direction of moving objects by analyzing how the phase angle of the instantaneous input impedance of the RMPA changes over time.