US 8,395,482 B2 · RFID systems using distributed exciter network

Abstract

RFID systems are disclosed that include at least one RFID receiver system and a distributed exciter architecture. The exciters can be connected via wired and/or wireless connections to the RFID receiver system and the RFID receiver system can control the activation of the exciters to detect the presence of RFID tags within interrogation spaces defined by the exciter topology. In several embodiments, the RFID receiver system performs location estimation to determine the interrogation space in which a specific RFID tag or collection of RFID tags is located. One embodiment of the invention includes an RFID receiver system configured to detect information from RFID tags within a receive coverage area, and a plurality of exciters defining a plurality of interrogation spaces within the receive coverage area of the RFID receiver system. In addition, the RFID receiver system is configured to transmit a control signal that identifies one of the plurality of exciters and includes information indicative of an RFID tag interrogation signal, the plurality of exciters are configured to receive the control signal, and the exciter identified in the control signal is configured to illuminate an interrogation space with the RFID tag interrogation signal.

Claims45

Dependent claims

An RFID system configured to manipulate RFID tags, comprising:

an RFID receiver system configured to detect information from RFID tags within a receive coverage area;
and
a plurality of exciters defining a plurality of interrogation spaces within the receive coverage area of the RFID receiver system;
wherein the RFID receiver system is configured to transmit a control signal that identifies one of the plurality of exciters and includes information indicative of an RFID tag interrogation signal;
wherein the plurality of exciters are configured to receive the control signal;
wherein the exciter identified in the control signal is configured to illuminate an interrogation space with the RFID tag interrogation signal;
the RFID receiver system is configured to transmit a status signal at a first RF frequency that identifies one of the plurality of exciters;
the exciter is configured to extract at least the identity of the exciter identified by the status signal;
and
the exciter is configured to generate a response signal and transmits the response signal at a second RF frequency.

7 more elements

A method of estimating the location of an RFID tag within a plurality of interrogation spaces, comprising:

repeatedly illuminating each of the plurality of interrogation spaces;
recording the illuminated interrogation space when the RFID tag is detected;
determining the rate at which the RFID tag is detected when each interrogation space is illuminated;
recording the rate at which the RFID tag is detected for each interrogation space and for each exciter;
obtaining information concerning the topology of the plurality of interrogation spaces;
estimating expected detection rates for RFID tags in different interrogation spaces using information concerning the interrogation space topography;
and
comparing the rate at which RFID tag information is detected when an interrogation space is illuminated with expected detection rates for the interrogation space when an RFID tag is located within different interrogation spaces.

5 more elements

Dependencies are inferred from the claim text.

RFID systems using distributed exciter network

Life of this patent

RFID systems using distributed exciter network

Life of this patent

Abstract

Claims45