Dual mode transmitter-receiver and decoder for RF transponder tags

• US 6,580,358 B1
• Filed: 05/17/2002
• Issued: 06/17/2003
• Est. Priority Date: 11/29/1996
• Status: Expired due to Fees

• Current Assignee: X-Cyte Inc.
• Original Assignee: X-Cyte Inc.
• Inventors: Nysen, Paul A.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): Dalencourt, Yves
• Application Number:
  US10/150,849
• Time in Patent Office: 396 Days
• Field of Search: 340/10.41, 340/10.1, 340/10.3, 340/10.4, 340/10.42, 340/10.51, 342/42, 342/44, 342/51
• US Class Current: 340/10.41
• CPC Class Codes: G01S 13/755 using delay lines, e.g. acoustic delay lines
• CPC Class Codes: G06K 19/0675 the resonating marks being of the surface acoustic wave [SAW] kind SAW devices per se H03H9/64
• 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: H03H 9/642 SAW transducers details for remote interrogation systems, e.g. surface acoustic wave transducers details for ID-tags remote interrogation systems per se G06K7/10009, G01S13/74

Abstract

An enhanced backscatter RF-ID tag reader system and multiprotocol RF tag reader system is provided. In a multiprotocol mode, the system emits a non-stationary interrogation signal, and decodes a phase modulated backscatter signal by detecting a stronger phase component from quadrature phase representations or determining phase transition edges in a phase of a received signal. The RF tag reader system predicts or follows the phase of the backscatter signal, thereby avoiding interference from nulls in the received signal waveform due to the non-stationary in terrogation signal, relative movement or environmental effects. An acoustic RF-ID tag detection system detects the reradiated signal corresponding to respective transformation of a signal in the tag. Detection of either type of RF-ID tags therefore is possible, and the absence of any tag or absence of any valid tag also determined.

Claims

1. A multiprotocol backscatter transponder identification system comprising a radio-frequency interrogation signal emitter, a backscatter response receiver, and an analyzer for analyzing the backscatter response to uniquely identify a transponder, said analyzer having separate processing channels for respectively analyzing different transponder protocols, each channel operative to analyze a protocol-specific time-variant sequence of distinct modulation states, wherein one of the protocols is read-only protocol, receiving identifying information from the transponder, and another of the protocols is a read/write protocol, communicating information bidirectional between transponder and transponder identification system, said system producing a common identification output.

2. The system to claim 1, where the analyzer comprises at least two channels selectively responsive to a respective protocol of two different CMOS transponders.

3. The system according to claim 1, wherein a first protocol comprises frequency shift keying of biphase encoded serial data bits identifying the transponder.

4. The system according to claim 1, wherein a second protocol comprises frequency shift keying of serial data bits, transmitted by the transponder in response to a modulation of said radio-frequency interrogation signal emitter.

5. The system according to claim 4, wherein said radio-frequency interrogation signal emitter communicates information to the transponder.

6. The system according to claim 2, where one of the at least two different protocols communicates information from a read-only transponder, and another of the at least two different protocols communicates information with a read/write transponder.

7. A dual protocol transponder identification system comprising a modulated interrogation signal transmitter transmitting a modulated interrogation signal, receiver for a receiving a backscatter signal induced by said interrogation signal, and an analyzer for analyzing the backscatter signal, said analyzer operating in a first mode to determine the transponder'"'"'s communication protocol, and in second mode to determine the unique identification number of the transponder, and wherein the modulation of the interrogation signal does not interfere with the determination of the unique identification number.

8. The system according to claim 7, where the analyzer'"'"'s first mode is capable of identifying at least two different protocols of CMOS transponders.

9. The system according to claim 8, where one of the at least two different protocols is employed by a read only transponder, and another of the at least two different protocols is employed by a read/write transponder.

10. A dual protocol transponder identification system, for retrieving identifying information from a population of different types of backscatter transponders, each respective type having a distinct and incompatible protocol for communication, a first protocol employing a multibit digital communication of information from the transponder identification system to the transponder and a second protocol not defining a multibit digital communication of information from the transponder identification system the transponder, comprising:

a transmitter for transmitting an interrogation signal, modulated with a signal for communicating with transponders according to the first protocol;

a receiver for receiving a backscatter communication from the transponders;

a control for controlling a modulation of the interrogation signal, a first set of circuitry for extracting from the backscatter communication a time-sequential series of digital data states;

a second set of circuitry for determining from the time-sequential series of digital data states, the identifying information; and

a common output, outputting the determined identification regardless of communication protocol, and suppressing spurious outputs nor representing a transponder, wherein the modulated interrogation signal does not interfer with the determination from the time-sequential series of digital data states of the identifying information for either protocol.

11. The system according to claim 10, wherein the second protocol comprises frequency shift keying of biphase encoded serial data bits identifying the transponder.

12. The system according to claim 10, wherein the first protocol comprises frequency shift keying of serial data bits, transmitted by the transponder in response to a modulation of said radio-frequency interrogation signal emitter.