Use of a subcarrier in an organic semiconductor radio frequency identification system
AssigneeMotorola, Inc.
InventorsTimothy J. Collins, Patrick L. Rakers
Life of this patent
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Abstract
A radio frequency identification system comprising a radio reader circuit operable to emit a radio frequency carrier signal modulated with a subcarrier, which has a subcarrier modulation rate. The radio frequency identification tag circuit is operable to extract the subcarrier from the emitted radio frequency carrier signal and the extracted subcarrier then functions as a clock, which operates to assist in the transfer of a modulated backscattered signal to the radio frequency identification reader circuit. The radio frequency identification reader circuit decodes the modulated backscattered signal and the data encoded in the radio frequency identification tag circuit is obtained.
Claims18
A radio frequency identification system comprising:
- a radio frequency identification reader circuit operable to emit a radio frequency carrier signal modulated with a subcarrier having a subcarrier modulation rate;
- and
- a radio frequency identification tag circuit comprising a field effect transistor formed from an organic semiconductor material that extracts the subcarrier from the emitted radio frequency carrier signal, wherein the subcarrier modulation rate is equal to or less than the switching rate of the field effect transistor and the extracted subcarrier functions as a clock operable to assist in the transfer of a modulated backscattered signal to the radio frequency identification reader circuit and wherein the modulated backscattered signal is decoded by the radio frequency identification reader circuit to obtain data encoded in the radio frequency identification tag circuit.
A method of operating a radio frequency identification system, comprising:
- emitting from a radio frequency identification reader a radio frequency carrier signal modulated by a subcarrier having a subcarrier modulation rate;
- extracting the subcarrier from the emitted radio frequency carrier signal by a first portion of a radio frequency identification tag circuit comprising a field effect transistor formed from an organic semiconductor material to obtain a clock signal, wherein the subcarrier modulation rate is equal to or less than the switching rate of the field effect transistor;
- extracting data stored on a second portion of the radio frequency identification tag circuit by synchronizing the clock signal to the stored data;
- and
- transmitting the extracted data to the radio frequency identification reader from the radio frequency identification tag circuit on a modulated backscattered signal.
A radio frequency identification system, comprising:
- means for emitting a subcarrier modulated radio frequency carrier signal from a radio frequency identification reader circuit, the subcarrier having a subcarrier modulation rate;
- means for extracting the subcarrier from the emitted radio frequency carrier signal at a radio frequency identification tag circuit comprising a field effect transistor formed from an organic semiconductor material to obtain a clock signal, wherein the subcarrier modulation rate is equal to or less than the switching rate of the field effect transistor;
- means for extracting data stored in the radio frequency identification tag circuit by synchronizing the clock signal to the stored data;
- and
- means for transmitting the extracted data to the radio frequency identification reader from the radio frequency identification tag circuit.
A radio frequency identification tag, comprising:
- a first circuit comprising a field effect transistor formed from an organic semiconductor material operable to receive a subcarrier modulated radio frequency carrier signal the subcarrier having a subcarrier modulation rate equal to or less than the switching rate of the field effect transistor, wherein the first circuit is operable to extract the subcarrier from the received subcarrier modulated radio frequency carrier signal emitted from a radio frequency identification reader, and wherein the extracted subcarrier is a clock signal;
- and
- a second circuit operable to utilize the clock signal to extract data stored on the radio frequency identification tag by synchronizing the clock signal to the stored data, wherein the first circuit and the second circuit are in electrical communication.
A radio frequency identification tag circuit, comprising:
- means for receiving a subcarrier modulated radio frequency carrier signal emitted from a radio frequency identification reader, the subcarrier having a subcarrier modulation rate;
- means comprising a field effect transistor formed from an organic semiconductor material for extracting the subcarrier from the received subcarrier modulated radio frequency carrier signal to obtain a clock signal, wherein the subcarrier modulation rate is equal to or less than the switching rate of the field effect transistor;
- means for extracting data stored in the radio frequency identification tag circuit by synchronizing the clock signal to the stored data;
- and
- means for transmitting the extracted data to the radio frequency identification reader from the radio frequency identification tag circuit.
Dependencies are inferred from the claim text.