System and Method for Measuring RFID Signal Strength Within Shielded Locations

• US 20090009333A1
• Filed: 07/14/2008
• Published: 01/08/2009
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Alexandre Polozoff, Gregory J. Boss, Kulvir S. Bhogal, Rick A. Hamilton II, Timothy M. Waters
• Original Assignee: Alexandre Polozoff, Gregory J. Boss, Kulvir S. Bhogal, Rick A. Hamilton II, Timothy M. Waters
• Inventors: Boss, Gregory J., Polozoff, Alexandre, Waters, Timothy M., Hamilton, Rick A. II, Bhogal, Kulvir S.
• Granted Patent: US 7,825,771 B2
• Time in Patent Office: Days
• US Class Current: 340/572.100
• CPC Class Codes: H04B 17/27 for locating or positioning the transmitter
• CPC Class Codes: H04B 17/318 Received signal strength

Abstract

An RFID Probe comprises a pole with a plurality of sensors that indicate RF signal strength attached at regular intervals and marked to indicate distance from an end of the pole. A user employs the RFID Probe by placing the probe between densely packed materials, such as cases on a pallet, and exposing the RFID Probe and packaging to a signal from a RIFD transceiver. After exposing the RFID Probe to the RFID transceiver signal, the user removes the RFID Probe from the packed materials and observes the sensors on the probe. By noting the location on the probe of the sensors indicating low or no RF signal, the user can identify locations where RF signal strength is insufficient to activate an RFID tag.

Claims

1. A process for systematically identifying a dead spot for an RF signal in a package stack comprising:

selecting a probe having a plurality of attached RF sensors adapted to provide an indication of the RF signal;

inserting the probe into the package stack;

transmitting the RF signal from a RFID transceiver;

removing the probe from the dense packaging; and

reading the sensors to identify a location of the RF signal dead spot

2. The process of claim 1 further comprising the step of:

placing an RF repeater to retransmit the RF signal to the dead spots.

3. The process of claim 1 wherein a plurality of passive RFID tags are affixed within the package stack.

4. The process of claim 3 further comprising the step of:

repositioning a passive RFID tag located in a dead spot within the package stack to an area of the package stack where the passive RFID tag can receive the RF signal.

5. The process of claim 1 further comprising:

calculating the location of the dead spot by measuring the distance from an end of the probe to an indicating sensor.

6. The process of claim 1 further comprising:

calculating the location of the dead spot by inserting the probe horizontally into the dense packaging and measuring a distance from a probe end to a first indicating sensor, and inserting the probe horizontally into the dense packaging and measuring the distance from the probe end to a second indicating sensor.

7. An apparatus for systematically identifying locations in dense packaging where RFID signals are too weak to activate passive RFID tags, the apparatus comprising:

a pole having a plurality of sensors spaced at regular intervals along the pole, wherein the sensors are adapted to provide an indication of an RF signal strength.

8. The apparatus of claim 7 wherein each of the plurality of sensors comprise an electronic display.

9. The apparatus of claim 8 wherein the electronic display further comprises a RFID receiver coupled to a LED.

10. The apparatus of claim 7 wherein each of the plurality of sensors comprises a RF sensitive LCD.

11. The apparatus of claim 7 wherein each of the plurality of sensors comprises a carbon coated acrylonitrile butadiene styrene plastic.

12. A system for identifying locations in dense packaging where RFID signals are too weak to activate passive RFID tags, comprising:

a pole having a plurality of sensors spaced at regular intervals along the pole, wherein the sensors are adapted to provide an indication of an RF signal strength and wherein each of the sensors comprise a RFID receiver coupled to a LED.