Method and apparatus for fault diagnosis in an RFID system

A radio frequency identification (RFID) system comprising:

• a plurality of antennas, each antenna comprising:
• a radio frequency (RF) power comparator configured to compare a power level indicator of a RF signal of the antenna with a RF signal power threshold;
• a bias voltage comparator configured to compare a bias voltage of the antenna with a bias voltage threshold;
• an RF fault bypass circuit configured to:
• function as an approximate open circuit when the bias voltage of the antenna is equal to or higher than the bias voltage threshold;
• function as an approximate short circuit when the bias voltage of the antenna is lower than the bias voltage threshold;
• an RFID reading circuitry configured to determine a fault in the RFID system using any of a RF power comparison, bias voltage comparison, and function of the RF fault bypass circuit;
• a first attenuating coupler of a first antenna configured to attenuate the RF signal of the first antenna to generate a first attenuated RF signal of the first antenna and a first step reduced RF signal of the first antenna;
• an RF power detector of the first antenna configured to receive the first attenuated RF signal of the first antenna and generate the power level indicator of the RF signal of the first antenna;
• an RF power comparator of the first antenna configured to:
• compare the power level indicator of the RF signal of the first antenna with the RF signal power threshold;
• and
• generate a first input to an IC tag of the first antenna using the comparison of the power level indicator of the RF signal of the first antenna and the RF signal power threshold;
• and
• a RF signal loss visual indicator of the first antenna configured to:
• receive the first input to the IC tag of the first antenna;
• and
• visually indicate whether the power level indicator of the RF signal of the first antenna is less than the RF signal power threshold.

A method for determining a fault in a radio frequency identification (RFID) system comprising:

• determining a failure by an antenna of an antenna chain of the RFID system in detecting a remote tag associated with the antenna;
• determining a prior antenna in the antenna chain as faulty if a radio frequency (RF) signal loss or a bias voltage loss is occurred in the prior antenna;
• determining the antenna is faulty if there are no RF signal loss or bias voltage loss in the prior antenna, and if an RFID reading circuitry is not able to communicate with an integrated circuit (IC) tag of the antenna or the RFID reading circuitry detects a jump in a return signal power from an IC tag of the antenna;
• and
• determining, when the RFID reading circuitry communicates with the IC tag of the antenna and the RFID reading circuitry does not detect the jump in the return signal power from an IC tag of the antenna:
• the antenna is faulty if an RF signal loss or a bias voltage loss is occurred in the antenna;
• and
• a radiating element of the antenna is faulty if the RF signal loss or the bias voltage loss is not occurred in the antenna;
• attenuating, by a first attenuating coupler of a first antenna, the RF signal of the first antenna to generate a first attenuated RF signal and a first step-reduced RF signal of the first antenna;
• receiving, by an RF power detector of the first antenna, the first attenuated RF signal of the first antenna;
• and
• generating, by the RF power detector, a power level indicator of the RF signal of the first antenna;
• comparing, by a RF power comparator of the first antenna, a power level indicator of the RF signal of the first antenna with a predefined RF signal power threshold;
• generating, by the RF power detector, a power level indicator of the RF signal of the first antenna;
• generating, by the RF power comparator, a first input to an (IC) tag of the first antenna based on the comparison of the power level indicator and the RF signal power threshold;
• receiving, by a RF signal loss visual indicator of the first antenna, the first input to the IC tag of the first antenna;
• and
• visually indicating, by the RF signal loss visual indicator, whether the power level indicator of the RF signal of the first antenna is less than the RF signal power threshold.