Object identification system with adaptive transceivers and methods of operation

• US 6,982,646 B2
• Filed: 08/03/2001
• Issued: 01/03/2006
• Est. Priority Date: 06/02/1998
• Status: Expired due to Fees

• Current Assignee: RF Code Incorporated
• Original Assignee: RF Code Incorporated
• Inventors: Rodgers, James L., Coulthard, John J., Lastinger, Roc A., Fowler, Billy C., Rehman, Mohammad A., Jaecks, Howard K., Picard, Paul A.
• Primary Examiner(s): Lee, Benjamin C.
• Application Number:
  US09/921,956
• Publication Number:
  US 20020011932A1
• Time in Patent Office: 1,614 Days
• Field of Search: 340/572.1, 340/572.7, 455/275, 455/277.1, 455/272, 455/466
• US Class Current: 340/572.7
• CPC Class Codes: G01S 13/753 using frequency selective elements, e.g. resonator
• CPC Class Codes: G01S 13/756 using a signal generator for modifying the reflectivity of the reflector G01S13/758 takes precedence
• CPC Class Codes: G01S 13/758 using a signal generator powered by the interrogation signal
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0724 the arrangement being a circuit for communicating at a plurality of frequencies, e.g. for managing time multiplexed communication over at least two antennas of different types
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10039 interrogator driven, i.e. synchronous
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: G08B 13/2417 having a radio frequency identification chip
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 5/35 using two or more simultaneously fed points
• CPC Class Codes: H01Q 5/40 Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 9/14 : Length of element or elements adjustable telescopic elements H01Q1/10

Abstract

An object identification system includes a monitor and a plurality of transceivers that communicate over a common medium. The monitor includes a first transmitter, a first receiver, and a processor. Each transceiver includes a resonant circuit, a transmitter, a receiver, and an antenna coupled to the resonant circuit. The processor performs a method for performing transceiver communication that includes the steps of: (a) transmitting from the first transmitter a first frequency for a first duration; (b) after lapse of the first duration, receiving via the first receiver a response signal from at least one of the resonant circuits; (c) determining a second frequency from the received response signal; and (d) performing transceiver communication using the second frequency. Transceivers of the type having a resonant circuit coupled to an antenna, when operating in close proximity to each other, may interfere with the response from a single transceiver by absorbing the energy intended to be received by the transceiver, absorbing the energy transmitted by the transceiver, or altering the resonant frequency of the resonant circuit. By determining the second frequency for transceiver communication, the monitor may establish communication with the single transceiver at a frequency better suited for transferring operative power to the transceiver, conducting an interrogation protocol for identifying the transceiver, or for data transfer.

Claims

1. A system comprising:

a. a monitor for determining whether a provided radio frequency identification device is present, determining being in accordance with a radio frequency signal input to the monitor; and

b. a plurality of antenna controllers coupled to the monitor via a provided network, the network for conveying one or more commands and for conveying the radio frequency signal, an antenna controller of the plurality comprising;

(1) a coupler;

(2) a radio frequency amplifier; and

(3) a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

wherein

c. in response to the one or more commands received from the monitor via the network and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface identified by the one or more commands to the amplifier for providing an amplified signal, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

2. An antenna controller comprising:

a. a network interface for coupling the antenna controller to a provided monitor via a provided network, the monitor for determining whether a provided radio frequency identification device is present in accordance with a radio frequency signal input to the monitor, and the network for conveying one or more commands and for conveying the radio frequency signal;

b. a coupler;

c. a radio frequency amplifier; and

d. a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

wherein

e. in response to the one or more commands received via the network interface and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface identified by the one or more commands to the amplifier for providing an amplified signal, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

3. A system comprising:

a. a monitor for determining whether a provided radio frequency identification device is present, determining being in accordance with a radio frequency signal input to the monitor; and

b. a plurality of antenna controllers coupled to the monitor via a provided network, the network for conveying one or more commands and for conveying the radio frequency signal, an antenna controller of the plurality comprising;

(1) a coupler;

(2) a radio frequency amplifier having an input;

(3) a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

(4) a memory; and

(5) a plurality of reactive elements;

wherein

c. in response to the one or more commands received from the monitor via the network and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface to the amplifier for providing an amplified signal, the memory provides contents for selectively coupling at least one of the reactive elements to the input of the amplifier, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

4. An antenna controller comprising:

a. a network interface for coupling the antenna controller to a provided monitor via a provided network, the monitor for determining whether a provided radio frequency identification device is present in accordance with a radio frequency signal input to the monitor, and the network for conveying one or more commands and for conveying the radio frequency signal;

b. a coupler;

c. a radio frequency amplifier having an input;

d. a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

e. a memory; and

f. a plurality of reactive elements;

wherein

g. in response to the one or more commands received from the monitor via the network interface and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface to the amplifier for providing an amplified signal, the memory provides contents for selectively coupling at least one of the reactive elements to the input of the amplifier, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

5. A system comprising:

a. a monitor for determining whether a provided radio frequency identification device is present, determining being in accordance with a radio frequency signal input to the monitor; and

b. a plurality of antenna controllers coupled to the monitor via a provided network, the network for conveying one or more commands and for conveying the radio frequency signal, an antenna controller of the plurality comprising;

(1) a coupler;

(2) a radio frequency amplifier having an input;

(3) a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

(4) a memory; and

(5) a plurality of reactive elements;

wherein

c. in response to the one or more commands received from the monitor via the network and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface to the amplifier for providing an amplified signal, the memory stores updated contents received via the network the memory provides contents for selectively coupling at least one of the reactive elements to the input of the amplifier, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

6. An antenna controller comprising:

a. a network interface for coupling the antenna controller to a provided monitor via a provided network, the monitor for determining whether a provided radio frequency identification device is present in accordance with a radio frequency signal input to the monitor, and the network for conveying one or more commands and for conveying the radio frequency signal;

b. a coupler;

c. a radio frequency amplifier having an input;

d. a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

e. a memory; and

f. a plurality of reactive elements, wherein

g. in response to the one or more commands received from the monitor via the network interface and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface to the amplifier for providing an amplified signal, the memory stores updated contents received via the network interface, the memory provides contents for selectively coupling at least one of the reactive elements to the input of the amplifier, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

7. A system comprising:

a. a monitor for determining whether a provided radio frequency identification device is present, determining being in accordance with a radio frequency signal input to the monitor; and

b. a plurality of antenna controllers coupled to the monitor via a provided network, the network for conveying one or more commands and for conveying the radio frequency signal, an antenna controller of the plurality comprising;

(1) a coupler;

(2) a radio frequency amplifier;

(3) a plurality of antenna interfaces, each for coupling a provided antenna to the coupler; and

(4) a squelch circuit coupled to the coupler;

wherein

c. in response to the one or more commands received from the monitor via the network and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface to the squelch circuit and to the amplifier for providing an amplified signal, the squelch circuit is operated to dissipate energy from the antenna interface prior to normal operation of the amplifier, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

8. An antenna controller comprising:

a. a network interface for coupling the antenna controller to a provided monitor via a provided network, the monitor for determining whether a provided radio frequency identification device is present in accordance with a radio frequency signal input to the monitor, and the network for conveying one or more commands and for conveying the radio frequency signal;

b. a coupler;

c. a radio frequency amplifier;

d. a plurality of antenna interfaces, each for coupling a provided antenna to the coupler; and

e. a squelch circuit coupled to the coupler;

wherein

f. in response to the one or more commands received from the monitor via the network interface and identified to the antenna controller by an address of the one or more commands, the coupler couples at least one antenna interface to the squelch circuit and to the amplifier for providing an amplified signal, the squelch circuit is operated to dissipate energy from the antenna interface prior to normal operation of the amplifier, and the antenna controller provides the radio frequency signal to the monitor in accordance with the amplified signal.

9. A system comprising:

a. a monitor for determining whether a provided radio frequency identification device is present determining being in accordance with a radio frequency signal input to the monitor; and

b. a plurality of antenna controllers coupled to the monitor via a provided network, the network for conveying one or more commands and for conveying the radio frequency signal, an antenna controller of the plurality comprising;

(1) a coupler;

(2) a radio frequency amplifier;

(3) a plurality of first interfaces, each for coupling a provided antenna to the coupler;

(4) a second interface for receiving an input signal to the antenna controller; and

(5) a difference circuit having first and second inputs for providing a difference signal as the algebraic difference of signals respectively from the first and second inputs;

wherein

c. in response to the one or more commands received from the monitor via the network and identified to the first antenna controller by an address of the one or more commands, the coupler couples at least one first interface to the amplifier for providing an amplified signal, the input signal of the second interface is coupled to the first input of the difference circuit, the amplified signal is coupled to the second input of the difference circuit, and the antenna controller provides the radio frequency signal to the monitor in accordance with the output of the difference circuit.

10. An antenna controller comprising:

a. a network interface for coupling the antenna controller to a provided monitor via a provided network, the monitor for determining whether a provided radio frequency identification device is present in accordance with a radio frequency signal input to the monitor, and the network for conveying one or more commands and for conveying the radio frequency signal;

b. a coupler;

c. a radio frequency amplifier;

d. a plurality of first interfaces, each for coupling a provided antenna to the coupler;

e. a second interface for receiving an input signal to the antenna controller; and

f. a difference circuit having first and second inputs for providing a difference signal as the algebraic difference of signals respectively from the first and second inputs;

wherein

g. in response to the one or more commands received from the monitor via the network interface and identified to the antenna controller by an address of the at least one command, the coupler couples at least one first interface to the amplifier for providing an amplified signal, the input signal of the second interface is coupled to the first input of the difference circuit, the amplified signal is coupled to the second input of the difference circuit, and the antenna controller provides the radio frequency signal to the monitor in accordance with the output of the difference circuit.

11. A system comprising:

a. a monitor for determining whether a provided radio frequency identification device is present, determining being in accordance with a radio frequency signal input to the monitor; and

b. a plurality of antenna controllers coupled to the monitor via a provided network, the network for conveying one or more commands and for conveying the radio frequency signal, an antenna controller of the plurality comprising;

(1) a first and a second coupler;

(2) a first and a second radio frequency amplifier;

(3) a plurality of first interfaces, each for coupling a provided antenna to the first coupler; and

(4) a difference circuit having first and second inputs for providing a difference signal as the algebraic difference of signals respectively from the first and second inputs;

wherein

c. in response to the one or more commands received from the monitor via the network and identified to the antenna controller by an address of the one or more commands, the first coupler couples at least one respective first interface to each of the first and the second amplifiers for providing first and second amplified signals respectively, the second coupler couples the first and the second amplified signals to a respective input of the difference circuit, and the antenna controller provides the radio frequency signal to the monitor in accordance with the difference signal.

12. An antenna controller comprising:

a. a network interface for coupling the antenna controller to a provided monitor via a provided network, the monitor for determining whether a provided radio frequency identification device is present in accordance with a radio frequency signal input to the monitor, and the network for conveying one or more commands and for conveying the radio frequency signal;

b. a first and a second coupler;

c. a first and a second radio frequency amplifier;

d. a plurality of antenna interfaces, each for coupling a provided antenna to the coupler;

e. a difference circuit having first and second inputs for providing a difference signal as the algebraic difference of signals respectively from the first and second inputs;

wherein

f. in response to the one or more commands received from the monitor via the network interface and identified to the antenna controller by an address of the one or more commands, the first coupler couples at least one respective first interface to each of the first and the second amplifiers for providing first and second amplified signals respectively, the second coupler couples the first and the second amplified signals to a respective input of the difference circuit, and the antenna controller provides the radio frequency signal to the monitor in accordance with the difference signal.