HYBRID TAG FOR RADIO FREQUENCY IDENTIFICATION SYSTEM

• US 20160292470A1
• Filed: 06/25/2015
• 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 9,734,371 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 7/10366 the interrogation device being adapted for miscellaneous applications
• CPC Class Codes: G06K 7/1097 Optical sensing of electronic memory record carriers, such as interrogation of RFIDs with an additional optical interface

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 method for reading data from a tag device, comprising:

receiving an optical signal from an interrogator device, wherein the received optical signal comprises an embedded clock signal;

converting the optical signal into an electrical signal which comprises the embedded clock signal;

extracting the embedded clock signal from the electrical signal;

utilizing the extracted clock signal as a clock signal for controlling clocking functions of the tag device; and

generating 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.

2. The method of claim 1, wherein the optical signal received from the interrogator device comprises a pulsed optical laser signal.

3. The method of claim 1, wherein converting the optical signal into an electrical signal comprises:

capturing photonic energy of the optical signal using one or more photodiodes operating in a photovoltaic mode; and

converting the captured photonic energy into a voltage or current signal.

4. The method of claim 1, further comprising:

performing a memory access operation to read out tag data that is stored in a memory of the tag device using the extracted clock signal;

generating a serial data bit stream comprising the read out tag data;

transmitting the serial data bit stream to the interrogator device.

5. The method of claim 4, wherein transmitting comprises:

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

changing an impedance of the loop antenna in response changes in logic levels of data bits of the serial data bit stream, 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.

6. The method of claim 5, wherein the loop antenna comprises a multi-loop antenna having a dimension that is smaller than a wavelength of the unmodulated RF carrier signal applied to the RF antenna of the interrogator device.