System to increase communication range of radio frequency identification (RFID) tag
AssigneeSilicon Craft Technology Public Company Limited (SICT)
InventorsSiriwan Visuttisen, Noparooj Tungcharoen, Sitthipong Wongnamkum
Life of this patent
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Abstract
A passive Radio Frequency Identification (RFID) tag with increased communication range is a novel passive RFID tag with increased communication range feature. The RFID tag includes antennas, RFID integrated circuit (RFID IC). The RFID IC includes various components such as resonant capacitor, front-ended circuit, digital controller and radio frequency (RF) signal strength detector. The method to increase communication range of RFID tags includes connecting RFID tags antenna to terminals of RFID IC, matching input RF signal, converting AC signal to DC signal, sensing current or voltage, comparing the output voltage, modulating and determining signal.
Claims6
A passive Radio Frequency Identification (RFID) tag with increased communication range comprising:
- a first Radio Frequency (RF) terminal;
- a second Radio Frequency (RF) terminal;
- an antenna configured to receive a Radio Frequency (RF) signal, transmitted wirelessly from a Radio Frequency Identification (RFID) reader and provide the received RF signal to the first RF terminal and the second RF terminal;
- a Radio Frequency Identification Integrated Circuit (RFID IC) connected to the antenna, the RFID IC comprising:
- a front-end circuit (AFE) configured to convert the received RF signal to a Direct Current (DC) signal to power the RFID IC, and to modulate the received RF signal for communication between the RFID reader and the RFID tag, the AFE comprising:
- a resonant capacitor coupled to the antenna and configured to tune the antenna to receive the RF signal,
- a rectifier coupled to the first RF terminal and the second RF terminal, and configured to convert the received RF signal to the DC signal, and
- an uplink modulator coupled to the first RF terminal and the second RF terminal, and configured to modulate the received RF signal with a modulation signal;
- a RF signal strength detector coupled to the rectifier and configured to detect strength of the RF signal, the RF signal strength detector comprising:
- a sensing circuit configured to receive the DC signal from the rectifier and generate an output signal indicative of the strength of the RF signal, and
- a comparator configured to receive the output signal from the sensing circuit and compare magnitude level of the output signal with a reference level to generate a comparator output signal to the RF control unit;
- a digital controller,
- wherein the digital controller comprising:
- a main control unit configured to provide a modulation data, and
- a RF control unit configured to receive the modulation data from the main control unit and provide the modulation signal to the uplink modulator,
- wherein the digital controller configured to:
- provide a control signal to control operation of the sensing circuit,
- determine a modulation pattern of the modulation signal by the RF control unit in response to the comparator output signal:
- when the comparator output signal is high, the modulation pattern of the modulation signal has a duty cycle of 50%, and
- when the comparator output signal is low, the modulation pattern of the modulation signal has a duty cycle of larger than 50%.
Dependencies are inferred from the claim text.