Radio frequency signal acquisition and source location system

• US 8,659,430 B2
• Filed: 03/15/2013
• Issued: 02/25/2014
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: RF Controls LLC
• Original Assignee: RF Controls LLC
• Inventors: Bloy, Graham P., Pierce, Matthew E., Hofer, Russell
• Primary Examiner(s): Lim, Steven
• Assistant Examiner(s): Fan, Hongmin
• Application Number:
  US13/835,145
• Publication Number:
  US 20130214907A1
• Time in Patent Office: 347 Days
• Field of Search: 340/572.1, 340/572.7, 340/572.4, 340/10.1, 342/42, 342/44, 342/147, 455/456.2, 455/456.1, 455/562.1, 343/700, 343/860
• US Class Current: 340/572.4
• CPC Class Codes: G01S 13/76 wherein pulse-type signals are transmitted
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: G01S 5/04 Position of source determined by a plurality of spaced direction-finders
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: G06K 7/01 Details
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G08B 13/2462 Asset location systems combined with EAS inventory, tracking, logistic G06Q10/00; entrance control systems G07C9/00
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 3/36 with variable phase-shifters

Abstract

A radio frequency signal acquistion and source location system, including a first signal acquisition and source location module comprising an RF transceiver coupled to an antenna, the antenna provided with a electronic steering circuit. The antenna operative to launch an interrogation signal, the interrogation signal steerable by an electronic steering circuit. A processor operatively coupled to the RF transceiver and the electronic steering circuit, the processor provided with a data storage for storing a signal data record for each of at least one response signal(s) received by the RF transceiver(s). The signal data record including a signal identification, a received signal strength indicator and an RF signal direction along which respective signal(s) are received by the antenna, the RF signal direction derived from the electronic steering circuit. A postion logic operative upon the data record(s) derives a three dimensional signal origin location of each response signal.

Claims

1. A radio frequency signal acquisition and source location system, comprising:

a first signal acquisition and source location module comprising an RF transceiver coupled to an antenna, the antenna provided with an electronic steering circuit;

the antenna operative to launch an interrogation signal, the interrogation signal steerable by the electronic steering circuit; and

a processor operatively coupled to the RF transceiver and the electronic steering circuit;

the processor provided with a data storage for storing a signal data record for each of at least one response signal(s) received by the RF transceiver(s);

the signal data record including a signal identification, a received signal strength indicator and an RF signal direction along which respective signal(s) are received by the antenna, the RF signal direction derived from the electronic steering circuit;

a discrimination logic, including a probability weighting factor, operative upon the data record(s) to filter the data record(s) between an actual signal(s) and a ghost signal(s); and

a position logic operative upon the data record(s) to derive a three dimensional signal origin location of each response signal.

2. The system of claim 1, wherein the electronic steering circuit directs each antenna through a sweep pattern of a zone to obtain the signal data record(s).

3. The system of claim 2, wherein the sweep pattern is a raster scan.

4. The system of claim 2, wherein the sweep pattern excludes selected areas within the zone.

5. The system of claim 1, wherein the position logic identifies a primary signal data record;

the primary signal data record being the signal data record in which the received signal strength indicator is the highest among signal data record(s) having a common signal identification;

the three dimensional signal origin location of each response signal derived from the RF signal direction of each of the primary signal data record(s) and the respective received signal strength indicator(s);

the received signal strength indicator proportional to a distance along the RF signal direction from the antenna.

6. The system of claim 1, further including a second signal acquisition and source location module and an edge server;

the edge server provided with a data connection with the first signal acquisition and source location module and the second signal acquisition and source location module;

the edge server receiving a primary signal data records from each of the first and second signal acquisition and source location modules and performing a triangulation operation upon the primary signal data records having a common signal identification to generate a higher order three dimensional signal origin location for each.

7. The system of claim 6, wherein the edge server compares successive three dimensional signal origin locations for each response signal to calculate a velocity of a corresponding response signal source.

8. The system of claim 6, wherein the edge server is integral with the first signal acquisition and source location module.

9. The system of claim 1, wherein at least one of the plurality of antennas is a phased array steerable antenna.

10. The system of claim 9, wherein the phased array steerable antenna is a panel or array provided with a plurality of radiating elements, each of the radiating elements individually drivable by the electronic steering circuit provided as a phase shifter controlled by a beam steering unit.

11. The system of claim 1, wherein the antenna has a transmit antenna element separate from a receive antenna element.

12. The system of claim 11, wherein the transmit and the receive elements are respective arrays of transmit and receive elements.

13. The system of claim 1, wherein the electronic steering circuit is a beam steering unit operatively coupled with a phase shifter of each of the antenna.

14. The system of claim 13, wherein the phase shifter is a plurality of phase shifters, one for each of a plurality of antenna elements of the antenna.

15. The system of claim 13, wherein the phase shifter includes an electronic phase shift element.

16. The system of claim 1, wherein the RF transceiver is an RFID reader.

17. The system of claim 1, wherein the interrogation signal is operative to initiate backscatter modulation in an RFID tag, and the response signal includes data representing at least a tag identification or item identity of each RFID tag initiated into back scatter modulation by the interrogation signal.

18. The system of claim 1, wherein the antenna and the electronic steering circuit are coupled to the processor by a digital data link.

19. The system of claim 1, wherein the plurality of antenna is positioned spaced apart and facing a zone.

20. The system of claim 19, wherein the antenna is positioned above the zone.