HYBRID TAG FOR RADIO FREQUENCY IDENTIFICATION SYSTEM

• US 20160294481A1
• Filed: 03/31/2015
• Published: 10/06/2016
• Est. Priority Date: 03/31/2015
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Friedman, Daniel J., Liu, Duixian, Sanduleanu, Mihai A.
• Granted Patent: US 9,755,701 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 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.

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 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 optical signal comprises an optical laser signal.

5. The tag device of claim 1, 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 transmitter circuitry using the clock signal.

6. The tag device of claim 1, wherein the transmitter circuitry comprises:

a loop antenna; and

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

7. The tag device of claim 6, wherein the loop antenna comprises a planar multi-loop antenna having a differential feed.

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

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

10. 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.

11. An interrogator device, comprising:

control circuitry configured to control functions of the interrogator device;

optical transmitter circuitry configured to generate and transmit an optical signal having an embedded clock signal to a tag device, wherein the embedded clock signal is recoverable by the tag device to control clocking functions of the tag device;

an antenna; and

receiver circuity configured to (i) apply an unmodulated radio frequency carrier signal to the antenna, (ii) detect changes in amplitude of an amplitude modulated backscattered radio frequency carrier signal which is reflected from the tag device and captured on the antenna, and (iii) recover a serial data bit stream comprising tag data transmitted from the tag device, based on the detected changes in said amplitude of the amplitude modulated backscattered radio frequency carrier signal.

12. The interrogator device of claim 11, wherein the optical transmitter circuitry comprises:

a laser-emitting device; and

driver circuitry configured to control modulation of the laser emitting device and cause the laser emitting device to generate and output a pulsed optical laser signal having the embedded clock signal.

13. The interrogator device of claim 12, wherein the pulsed optical laser signal comprises a duty cycle of approximately 50%.

14. The interrogator device of claim 12, wherein the laser-emitting device comprises a vertical-cavity surface-emitting laser diode.

15-20. -20. (canceled)