Method and apparatus for verifying RFID tags

An apparatus to verify RFID tags, comprising:

• an RF interrogator configured to selectively transmit a first interrogation signal at a first time and a second interrogation signal at a second time, the first interrogation signal having a first operational characteristic that differs from a corresponding first operational characteristic of the second interrogation signal, and to receive a first return signal returned from an RFID tag in response to the first interrogation signal and a second return signal returned from the RFID tag in response to the second interrogation signal;
• a processor coupled to the RF interrogator and configured to determine an operational response of the RFID tag in the form of at least a second operational characteristic of the first and the second return signals;
• and
• a machine-readable symbol verifier positioned to verify a machine-readable symbol on the RFID tag.

An apparatus to verify RFID tags, comprising:

• an RF interrogator configured to selectively transmit a first interrogation signal at a first time and a second interrogation signal at a second time, the first interrogation signal having a first operational characteristic that differs from a corresponding first operational characteristic of the second interrogation signal, and to receive a first return signal returned from an RFID tag in response to the first interrogation signal and a second return signal returned from the RFID tag in response to the second interrogation signal;
• a processor coupled to the RF interrogator and configured to determine an operational response of the RFID tag in the form of at least a second operational characteristic of the first and the second return signals;
• and
• a machine-readable symbol imager positioned to image a machine-readable symbol on the RFID tag and coupled to the processor to supply the image data thereto, the processor being configured to verify the image data.

An apparatus to verify RFID tags, comprising:

• an RF interrogator configured to selectively transmit a first interrogation signal at a first time and a second interrogation signal at a second time, the first interrogation signal having a first operational characteristic that differs from a corresponding first operational characteristic of the second interrogation signal, and to receive a first return signal returned from an RFID tag in response to the first interrogation signal and a second return signal returned from the RFID tag in response to the second interrogation signal;
• a processor coupled to the RF interrogator and configured to determine an operational response of the RFID tag in the form of at least a second operational characteristic of the first and the second return signals;
• and
• a machine-readable symbol imager positioned to image a machine-readable symbol on the RFID tag and coupled to the processor to supply the image data thereto, the processor configured to verify the image data and to provide a grade based on the verification of the image data and the comparison of the response of the RFID tag to the predetermined response.

A method to verify RFID tags, comprising:

• selectively transmitting a first interrogation signal having a first operational characteristic;
• selectively transmitting a second interrogation signal having a first operational characteristic that differs from the corresponding first operational characteristic of the first interrogation signal by a defined amount;
• receiving a first return signal returned from an RFID tag in response to the first interrogation signal, the first return signal having a second operational characteristic wherein receiving a first return signal having a second operational characteristic includes detecting the first return signal of a first frequency;
• receiving a second return signal returned from the RFID tag in response to the second interrogation signal, the second return signal having a second operational characteristic corresponding to the second operational characteristic of the first return signal wherein receiving a second return signal having a second operational characteristic includes detecting the second return signal of a second frequency that differs from the first frequency;
• and
• determining a response of the RFID tag corresponding to the second operational characteristic of at least the first and the second return signals.

A method to verify RFID tags, comprising:

• selectively transmitting a first interrogation signal having a first operational characteristic;
• selectively transmitting a second interrogation signal having a first operational characteristic that differs from the corresponding first operational characteristic of the first interrogation signal by a defined amount;
• receiving a first return signal returned from an RFID tag in response to the first interrogation signal, the first return signal having a second operational characteristic;
• receiving a second return signal returned from the RFID tag in response to the second interrogation signal, the second return signal having a second operational characteristic corresponding to the second operational characteristic of the first return signal;
• and
• determining a response of the RFID tag corresponding to the second operational characteristic of at least the first and the second return signals wherein determining a response of the RFID tag corresponding to the second operational characteristic of at least the first and the second return signals includes determining a slope of a function including at least a first point corresponding to the first operational characteristic of first interrogation signal and the second operational characteristic of the first return signal, and a second point corresponding to the first operational characteristic of the second interrogation signal and the second operational characteristic of the second return signal.