Hybrid tag for radio frequency identification system

• US 9,755,701 B2
• Filed: 03/31/2015
• Issued: 09/05/2017
• Est. Priority Date: 03/31/2015
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Friedman, Daniel J., Liu, Duixian, Sanduleanu, Mihai A.
• Primary Examiner(s): Bugg, George
• Assistant Examiner(s): TRAN, THANG DUC
• Application Number:
  US14/673,916
• Publication Number:
  US 20160294481A1
• Time in Patent Office: 889 Days
• Field of Search: 340 101- 106, 3405721-5729
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: H04B 10/803 Free space interconnects, e.g. between circuit boards or chips
• CPC Class Codes: H04B 5/77 for interrogation

Abstract

RFID (radio frequency identification) systems are provided in which tag and interrogator devices implement a hybrid framework for signaling including an optical transmitter/receiver system and an RF transmitter/receiver system. For instance, an RFID tag device includes: optical receiver circuitry configured to receive an optical signal having an embedded clock signal from an interrogator device, and convert the optical signal into an electrical signal comprising the embedded clock signal; clock extraction circuitry configured to extract the embedded clock signal from the electrical signal, and output the extracted clock signal as a clock signal for controlling clocking functions of the tag device; voltage regulator circuitry configured to generate a regulated supply voltage from the electrical signal, wherein the regulated supply voltage is utilized as a bias voltage for components of the tag device; and data transmitter circuitry configured to wirelessly transmit tag data to the interrogator device.

Claims

1. A tag device, comprising:

a substrate comprising a plurality of components integrally formed thereon, wherein the components comprise;

state machine control circuitry configured to control functions of the tag device;

a non-volatile memory configured to store tag data;

optical receiver circuitry configured to receive a pulsed optical signal having an embedded clock signal from an interrogator device, and convert the pulsed optical signal into an electrical signal which represents the embedded clock signal within the pulsed optical signal which is optically transmitted from the interrogator device to control clocking functions of the tag device;

clock extraction circuitry configured to extract the embedded clock signal from the electrical signal output from the optical receiver circuitry, and output the extracted clock signal as a clock signal for controlling the clocking functions of the tag device;

voltage regulator circuitry configured to generate a regulated supply voltage from the electrical signal output from the optical receiver circuitry, wherein the regulated supply voltage is utilized as a bias voltage for components of the tag device;

data transmitter circuitry configured to wirelessly transmit tag data to the interrogator device;

wherein the clock signal is input to the state machine control circuitry to control a memory access operation of the non-volatile memory, wherein the memory access operation comprises reading out the stored tag data as a serial data bit stream that is serially clocked to the data transmitter circuitry using the clock signal; and

wherein the data transmitter circuitry comprises;

a loop antenna; and

switching circuitry that is configured to change an impedance of the loop antenna in response to the serial data bit stream which comprises tag data that is read out from the non-volatile memory;

wherein changing the impedance of the loop antenna modulates RF power on the loop antenna and causes modulated RF power encoded with the serial data bit stream to be reflected back to an RF antenna of the interrogator device.

2. The tag device of claim 1, wherein the optical receiver circuitry comprises one or more photodiodes that are configured to operate in a photovoltaic mode to convert photonic energy of the pulsed optical signal into a current.

3. The tag device of claim 2, wherein the one or more photodiodes are connected in a stacked configuration comprising a plurality of serially connected photodiode stages, wherein at least one photodiode stage comprises a plurality of parallel connected photodiodes.

4. The tag device of claim 1, wherein the pulsed optical signal comprises a pulsed optical laser signal.

5. The tag device of claim 1, wherein the loop antenna comprises a planar multi-loop antenna having a differential feed.

6. The tag device of claim 1, wherein one or more of the components of the tag device are disposed within an inner loop area of the loop antenna.

7. The tag device of claim 1, wherein the substrate comprises a flexible substrate.

8. The tag device of claim 1, wherein each of a length, width, and thickness dimension of the tag device is about 75 microns or less.

9. A tag device, comprising:

a substrate comprising a plurality of components integrally formed thereon, wherein the components comprise;

state machine control circuitry configured to control functions of the tag device;

a non-volatile memory configured to store tag data;

optical receiver circuitry configured to receive a pulsed optical signal having an embedded clock signal from an interrogator device, and convert the pulsed optical signal into an electrical signal which represents the embedded clock signal within the pulsed optical signal which is optically transmitted from the interrogator device to control clocking functions of the tag device;

clock extraction circuitry configured to extract the embedded clock signal from the electrical signal output from the optical receiver circuitry, and output the extracted clock signal as a clock signal for controlling the clocking functions of the tag device;

voltage regulator circuitry configured to generate a regulated supply voltage from the electrical signal output from the optical receiver circuitry, wherein the regulated supply voltage is utilized as a bias voltage for components of the tag device; and

data transmitter circuitry configured to wirelessly transmit tag data to the interrogator device;

wherein the clock signal is input to the state machine control circuitry to control a memory access operation of the non-volatile memory, wherein the memory access operation comprises reading out the stored tag data as a serial data bit stream that is serially clocked to the data transmitter circuitry using the clock signal;

wherein the data transmitter circuitry comprises;

a loop antenna; and

switching circuitry that is configured to change an impedance of the loop antenna in response to the serial data bit stream which comprises the tag data that is read out from the non-volatile memory;

wherein the switching circuitry is configured to change the impedance of the loop antenna by selectively connecting and disconnecting the loop antenna to a ground terminal, based on logic levels of the data bits in the serial data bit stream applied to the switching circuitry;

wherein the loop antenna on the tag device is configured to magnetically couple RF power from an unmodulated RF carrier signal applied to an RF antenna of the interrogator device; and

wherein changing the impedance of the loop antenna modulates the RF power on the loop antenna and causes modulated RF power encoded with the serial data bit stream to be reflected back to the RF antenna of the interrogator device.

10. The tag device of claim 9, wherein the loop antenna comprises a planar multi-loop antenna having a differential feed.

11. The tag device of claim 9, wherein each of a length, width, and thickness dimension of the tag device is about 75 microns or less.

12. The tag device of claim 9, wherein the optical receiver circuitry comprises one or more photodiodes that are configured to operate in a photovoltaic mode to convert photonic energy of the pulsed optical signal into a current.

13. The tag device of claim 12, wherein the one or more photodiodes are connected in a stacked configuration comprising a plurality of serially connected photodiode stages, wherein at least one photodiode stage comprises a plurality of parallel connected photodiodes.

14. The tag device of claim 9, wherein the substrate comprises a flexible substrate.