Rfid reader with automatic tuning
AssigneeRF IDeas, Inc.
InventorsJohn C. Butera, Rajani Pidaparti
Life of this patent
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Abstract
An RFID reader, tuning method and computer readable medium. A carrier signal is transmitted. A plurality of feedback signals produced in the RFID reader are measured when transmitting the carrier signal with a variable matching network set at a plurality of impedance values that are different from one another. It is determined which impedance value of the plurality of impedance values produced a feedback signal having a highest level of the plurality of feedback signals. The variable matching network is set to the determined impedance value.
Claims20
A tuning method for an RFID reader, the tuning method comprising:
- transmitting a carrier signal;
- measuring a plurality of feedback signals produced in the RFID reader when transmitting the carrier signal with a variable matching network set at a plurality of impedance values that are different from one another;
- determining which impedance value of the plurality of impedance values produced a feedback signal having a highest level of the plurality of feedback signals;
- and
- setting the variable matching network to the determined impedance value.
A control circuit for an RFID reader, comprising:
- circuitry configured to:
- measure a plurality of feedback signals produced in the RFID reader when transmitting the carrier signal with a variable matching network set at a plurality of impedance values that are different from one another;
- determine which impedance value of the plurality of impedance values produced a feedback signal having a highest level of the plurality of feedback signals;
- and
- set the variable matching network to the determined impedance value to read an RFID tag.
An RFID reader, comprising:
- a transmitter/receiver circuit having a transmit terminal and a receive terminal;
- a variable matching network coupled to the transmit terminal;
- a feedback circuit configured to provide a voltage representing a signal transmitted by the transmitter/receiver circuit to the receive terminal as a feedback signal;
- and
- a controller configured to vary an impedance of the variable matching network,
- wherein the RFID reader is configured to determine an impedance of the variable matching network that produces a highest feedback signal at the receive terminal of the transmitter/receiver circuit, and to set the variable matching network to the determined impedance value to read an RFID tag.
Dependencies are inferred from the claim text.