Printed Radio Frequency Identification (RFID) Tag Using Tags-Talk-First (TTF) Protocol
First Claim
1. A tag configured to wirelessly communicate with a reader in a multi-tag read-capable system using a tags-talk-first (TTF) anti-collision scheme, the tag comprising:
- a) a memory portion storing a plurality of memory bits, the plurality of memory bits encoding an identifier for the tag, and said memory portion comprising at least one printed layer; and
b) a circuit configured to (i) transmit a bit string to the reader, said bit string being related to said identifier, (ii) cause said tag to remain silent for a unique silent period following complete transmission of said bit string, said unique silent period being determined by variations in environmental parameters, physical parameters, and/or electrical performance of components within said tag, including variations in said printed layer(s) of the memory portion, and (iii) retransmit said bit string after said unique silent period elapses, wherein said circuit comprises;
(i) an antenna configured to receive a radio frequency (RF) signal from said reader;
(ii) a power-up circuit coupled to said antenna, said power-up circuit being configured to provide an enable signal when said RF signal is received by the antenna; and
(iii) control and readout logic configured to perform control and readout functions of the tag, comprising a plurality of thin film transistors (TFTs).
1 Assignment
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Accused Products
Abstract
A method, algorithm, architecture, circuits, and/or systems for EAS, HF, UHF, and RFID designs suitable for multi-tag read applications using TTF anti-collision schemes are disclosed. In one embodiment, a tag for wirelessly communicating with a reader can include: (i) a memory portion with an identifier, the memory having at least one printed layer; and (ii) a circuit for providing a bit string followed by a predetermined silent period, where the bit string is related to the identifier. The tag can include pre-programmed memory bits (e.g., bits the value of which is programmed by printing), or alternatively, memory bits formed by conventional photolithography, but having connections made using printing technology to form the identifier, for example. A unique identifier for each tag or device used in a system under a given set of operating conditions can allow a reader to distinguish between them based on a length and/or value of a bit string, for example. Embodiments of the present invention can advantageously provide a reliable and simplified approach for multi-tag read capable EAS, HF, UHF, and RFID systems using TTF anti-collision schemes.
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Citations
20 Claims
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1. A tag configured to wirelessly communicate with a reader in a multi-tag read-capable system using a tags-talk-first (TTF) anti-collision scheme, the tag comprising:
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a) a memory portion storing a plurality of memory bits, the plurality of memory bits encoding an identifier for the tag, and said memory portion comprising at least one printed layer; and b) a circuit configured to (i) transmit a bit string to the reader, said bit string being related to said identifier, (ii) cause said tag to remain silent for a unique silent period following complete transmission of said bit string, said unique silent period being determined by variations in environmental parameters, physical parameters, and/or electrical performance of components within said tag, including variations in said printed layer(s) of the memory portion, and (iii) retransmit said bit string after said unique silent period elapses, wherein said circuit comprises; (i) an antenna configured to receive a radio frequency (RF) signal from said reader; (ii) a power-up circuit coupled to said antenna, said power-up circuit being configured to provide an enable signal when said RF signal is received by the antenna; and (iii) control and readout logic configured to perform control and readout functions of the tag, comprising a plurality of thin film transistors (TFTs). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 12)
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9. A method of making a tag for wirelessly communicating with a reader in a multi-tag read capable system using a tags-talk-first (TTF) anti-collision scheme, comprising:
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a) printing at least one layer of a memory portion of the tag, the memory portion storing a plurality of memory bits encoding an identifier for the tag; and b) forming a circuit on the tag configured to (i) transmit a bit string to the reader, said bit string being related to said identifier, (ii) cause said tag to remain silent for a unique silent period following complete transmission of said bit string, said unique silent period being determined by variations in environmental parameters, physical parameters, and/or electrical performance of components within said tag, including in said printed layer(s) of the memory portion, and (iii) retransmit said bit string after said unique silent period elapses, wherein said circuit comprises; i) an antenna configured to receive a radio frequency (RF) signal from said reader; ii) a power-up circuit coupled to said antenna, said power-up circuit being configured to provide an enable signal when said RF signal is received by the antenna; and iii) control and readout logic configured to perform control and readout functions of the tag, comprising a plurality of thin film transistors (TFTs). - View Dependent Claims (10, 11)
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13. A wireless identification system for a multi-tag read application using a tags-talk-first (TTF) anti-collision scheme, comprising:
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a) a first tag having a first memory portion storing a first plurality of memory bits encoding a first identifier, wherein at least one layer of said first memory portion is printed, said first tag including a first circuit configured to (i) transmit a first bit string to a reader when an electromagnetic field is applied, said first bit string being related to said first identifier, (ii) cause said first tag to remain silent for a first unique period of time following complete transmission of said first bit string, said first unique period of time having a length and/or value that is determined by variations in environmental parameters, physical parameters, and/or electrical performance of components within said first tag, including in said printed layer(s) of the first memory portion, and (iii) retransmit said first bit string after said first unique period of time elapses; b) a second tag having a second memory portion storing a second plurality of memory bits encoding a second identifier, wherein at least one layer of said second memory portion is printed, said second tag including a second circuit configured to (i) transmit a second bit string to a reader when said electromagnetic field is applied, said second bit string being related to said second identifier, (ii) cause said second tag to remain silent for a second unique period of time following complete transmission of said second bit string, said second unique period of time having a length and/or value that is determined by variations in environmental parameters, physical parameters, and/or electrical performance of components within said second tag, including in said printed layer(s) of the second memory portion, and (iii) retransmit said second bit string after said second unique period of time elapses; and c) said reader, configured to receive said first and second bit strings and distinguish between said first and second tags based on said first and second bit strings, wherein each of said first and second circuits comprises; i) an antenna configured to receive a radio frequency (RF) signal from said reader; ii) a power-up circuit coupled to said antenna, said power-up circuit being configured to provide an enable signal when said RF signal is received by the antenna; and iii) control and readout logic configured to perform control and readout functions of the tag, comprising a plurality of thin film transistors (TFTs). - View Dependent Claims (14, 15, 16)
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17. A group of tags configured to communicate wirelessly with a reader in a multi-tag read capable system using a tags-talk-first (TTF) anti-collision scheme, each tag in the group comprising:
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a) a memory portion storing a plurality of memory bits, the plurality of memory bits encoding a unique identifier for the tag, said memory portion comprising at least one printed layer; and b) a circuit configured to(i) transmit a bit string to the reader, said bit string being related to said identifier, (ii) cause said tag to remain silent for a unique silent period following complete transmission of said bit string, said unique silent period being determined by variations in environmental parameters, physical parameters, and/or electrical performance of components within said tag, including variations in said printed layer(s) of the memory portion, and (iii) retransmit said bit string after said unique silent period elapses, wherein said circuit comprises; (i) an antenna configured to receive a radio frequency (RF) signal from said reader; (ii) a power-up circuit coupled to said antenna, said power-up circuit being configured to provide an enable signal when said RF signal is received by the antenna; and (iii) control and readout logic configured to perform control and readout functions of the tag, comprising a plurality of thin film transistors (TFTs). - View Dependent Claims (18, 19, 20)
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Specification