Method and apparatus for locating objects using radio frequency identification
AssigneeThe Boeing Company
InventorsSandor Holly, Robert Alan Smith
Life of this patent
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Abstract
A method and apparatus for detecting non-linear tags. In one advantageous embodiment a system for detecting non-linear tags has a transmitter and a receiver. The transmitter transmits a plurality of electromagnetic signals having a first frequency and a second frequency. The receiver monitors for an electromagnetic signal having a frequency equal to a difference between the first frequency and a second frequency that is generated by a non-linear tag in response to receiving the plurality of electromagnetic signals, wherein the non-linear tag is detected when the electromagnetic signal is detected by the receiver.
Claims20
A system for detecting non-linear radio frequency identification tags, the system comprising:
- a transmitter, wherein the transmitter transmits a plurality of electromagnetic signals having a first frequency and a second frequency;
- and
- a receiver, wherein the receiver monitors for an electromagnetic signal having a third frequency equal to a difference between the first frequency and the second frequency, wherein the electromagnetic signal is generated by a non-linear tag in response to the non-linear tag receiving the plurality of electromagnetic signals, wherein the non-linear tag comprises an antenna, a logic control circuit, a memory, a power supply, and a sensor, and wherein the non-linear tag is detected when the electromagnetic signal at the third frequency is detected by the receiver.
A non-linear tag comprising:
- a non-linear element, wherein the non-linear element receives electromagnetic signals, and wherein the electromagnetic signals comprise a first frequency and a second frequency;
- and
- a logic circuit, wherein the logic circuit causes the non-linear element to emit information in a response signal having a third carrier frequency equal to a difference between the first frequency and the second frequency in response to the non-linear element receiving the electromagnetic signals.
A method for detecting tags, the method comprising:
- transmitting a plurality of electromagnetic signals having a first frequency and a second frequency;
- and
- monitoring for an electromagnetic signal generated by a non-linear tag, wherein the electromagnetic signal comprises a third carrier frequency equal to a difference between the first frequency and the second frequency, and wherein the non-linear tag generates the electromagnetic signal in response to receiving the plurality of electromagnetic signals, wherein the non-linear tag comprises an antenna, a logic control circuit, a memory, a power supply, and a sensor;
- and
- detecting a tag having a non-linear element when the electromagnetic signal is detected.
Dependencies are inferred from the claim text.