EP0638819A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method for detecting adjacent transponders
Assignee: Texas Instruments Deutschland GmbH
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Filing: 1994-08-11
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Granted: —
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Expires: 2014-08-11
Abstract
Abstract A method for interrogating remote transponders having the steps of: sending an RF interrogation pulse from an interrogator (10), receiving by a first and second transponder (12,12a) the RF interrogation pulse, and establishing in a resonant circuit (130) of each of the transponders (12,12a) an oscillation, the oscillation being established by the coupling of signal energy from the RF interrogation pulse into the resonant circuit (130). After the RF interrogation pulse ends, the first transponder (12) senses the termination of the pulse and initiates a first RF response having a selected duration. A second RF response from the second transponder (12a) will also be detected in the first transponder (12) whose response will be affected by this second RF response. The differing response times in the first transponder (12) for responses affected and unaffected by neighboring transponders may be sensed in the interrogator so the interrogator may detect instances in which the RF responses which it received may have been conflicting.
Inventors
- 👤 Josef H. Schuermann
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 11:33
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10009; G06K7/10019; G06K7/10029; G06K7/10039; G01; G01S; G01S13/00; G01S13/74; G01S13/75; G01S13/751; G01S13/758; G06K7/0008
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
84 words
A method for interrogating remote transponders, said method comprising the steps of: sending an interrogation pulse from an interrogator; receiving by a first and second transponder said interrogation pulse; terminating said interrogation pulse; sensing in said first transponder termination of said interrogation pulse; initiating in said first transponder an response having a selected duration; sensing in said first transponder signals from said second transponder; and modifying the duration of said response in said first transponder upon detection of said signals from said second transponder.
Claim 2
Independent Claim
84 words
A method for interrogating remote transponders, said method comprising the steps of: sending an interrogation pulse from an interrogator; receiving by a first and second transponder said interrogation pulse; terminating said interrogation pulse; sensing in said first transponder termination of said interrogation pulse; initiating in said first transponder an response having a selected duration; sensing in said first transponder signals from said second transponder; and modifying the duration of said response in said first transponder upon detection of said signals from said second transponder.
Claim 3
Dependent Claim
38 words
The method of claim 1, further comprising the step of receiving said RF response by said interrogator and analyzing the duration thereof to determine if both of said first and second transponders are within proximity of said interrogator.
Claim 4
Dependent Claim
25 words
The method of claim 1 or claim 2, further comprising the step of selectively addressing by said interrogator one of said first and second transponders.
Claim 5
Independent Claim
16 words
The method of any preceding claim, further comprising providing said first transponder as a half-duplex transponder.
Claim 6
Independent Claim
16 words
The method of any preceding claim, further comprising providing said second transponder as a half-duplex transponder.
Claim 7
Independent Claim
19 words
The method of any of claims 1 to 4, further comprising providing said second transponder as a full-duplex transponder.
Claim 8
Independent Claim
35 words
The method of any preceding claim, further comprising providing said first transponder having a resonant circuit for receiving said interrogation pulse and for establishing an oscillation in said resonant circuit in response to said interrogation.
Claim 9
Dependent Claim
43 words
The method of claim 7, wherein said sensing in said first transponder of said signals from said second transponder is accomplished by sensing destructive interference between said oscillation established in the resonant circuit of said first transponder and signals from said second transponder.
Claim 10
Independent Claim
26 words
The method of any preceding claim, further comprising selecting said duration by a counter that counts up to a pre-selected number of oscillations in said resonator.
Claim 11
Independent Claim
30 words
The method of any preceding claim, further comprising providing said interrogation pulse, said response and said signals as an RF interrogation pulse, an RF response and an RF signal respectively.
Claim 12
Dependent Claim
134 words
An arrangement for interrogating remote transponders, said arrangement comprising: an interrogator operable to send an interrogation pulse and to receive an response; a transponder in proximity to said interrogator, at least a first transponder having a resonant circuit operable to receive said interrogations from said interrogator and to establish an oscillation therein from the signal energy within said interrogation pulse; a transponder end-of-burst detector in electrical communication with said resonant circuit for detecting the end of the interrogation pulse; a transponder transmitter in electrical communication with said end-of-burst detector for transmitting an response to said interrogator; a transponder counter for determining when the response message from said transponder is complete and for disabling said transmitter; and a response signal detector in said transponder for detecting responses from adjacent transponders and resetting said transponder counter.
Claim 13
Dependent Claim
134 words
An arrangement for interrogating remote transponders, said arrangement comprising: an interrogator operable to send an interrogation pulse and to receive an response; a transponder in proximity to said interrogator, at least a first transponder having a resonant circuit operable to receive said interrogations from said interrogator and to establish an oscillation therein from the signal energy within said interrogation pulse; a transponder end-of-burst detector in electrical communication with said resonant circuit for detecting the end of the interrogation pulse; a transponder transmitter in electrical communication with said end-of-burst detector for transmitting an response to said interrogator; a transponder counter for determining when the response message from said transponder is complete and for disabling said transmitter; and a response signal detector in said transponder for detecting responses from adjacent transponders and resetting said transponder counter.
Claim 14
Dependent Claim
21 words
The arrangement of claim 11, wherein said transponder end-of-burst detector and said transponder transmitter have intervening control circuitry for control thereof.
Claim 15
Dependent Claim
19 words
The arrangement of claim 11 or claim 12, wherein said interrogator has an antenna for receiving said RF responses.
Claim 16
Dependent Claim
27 words
The arrangement of claim 13, wherein said interrogator further comprises a "read" circuit in electrical communication with said antenna for detecting valid data returned from said transponders.
Claim 17
Dependent Claim
31 words
15 The transponder of claim 14, wherein said interrogator further comprises a timer circuit in electrical communication with said antenna for measuring the duration of said response from said first transponder.
Claim 18
Dependent Claim
24 words
The transponder of claim 15, wherein said interrogator further comprises a decoder in electrical communication with said "read" circuitry and with said timer circuit.
Claim 19
Dependent Claim
15 words
The transponder of any of claims 11 to 16 operating in the RF frequency range.
Claim 20
Dependent Claim
128 words
An interrogator for determining if an interrogation therefrom is received by more than one transponder, said interrogator comprising: a "send" antenna for transmitting an interrogation pulse to transponders; a "receive" antenna for receiving an response from at least one of said transponders; a "read" circuit in electrical communication with said "receive" antenna, said read circuitry operable to extract a data signal from said response; a timer in electrical communication with said "receive" antenna, said timer operable to measure the duration of said response; and a decoder in electrical communication with said read circuitry and with said timer, said decoder operable to interpret from the signals received from said read circuitry and said timer if a valid response was received from a single transponder without interference from another responder.
Claim 21
Dependent Claim
128 words
An interrogator for determining if an interrogation therefrom is received by more than one transponder, said interrogator comprising: a "send" antenna for transmitting an interrogation pulse to transponders; a "receive" antenna for receiving an response from at least one of said transponders; a "read" circuit in electrical communication with said "receive" antenna, said read circuitry operable to extract a data signal from said response; a timer in electrical communication with said "receive" antenna, said timer operable to measure the duration of said response; and a decoder in electrical communication with said read circuitry and with said timer, said decoder operable to interpret from the signals received from said read circuitry and said timer if a valid response was received from a single transponder without interference from another responder.
References Cited (Backward Citations)
No citation records indexed.
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