Patent ID: 8111162

Claim:
A method of operation of a transponder detection device, the method comprising: during each of a plurality of detection cycles, receiving electromagnetic signals by a receiver during a noise detection portion of the detection cycle; determining a noise value indicative of a noise level that corresponds to a highest one of a number N of samples or measurements of the electromagnetic signals received during the noise detection portion of the detection cycle by a processor circuit, where the number N is greater than one; adjusting a signal detection threshold by the processor circuit based at least in part on the determined noise value of at least one of the detection cycles; emitting at least one electromagnetic interrogation signal during a transmit portion of the detection cycle by a transmitter; receiving electromagnetic signals by the receiver during a receive response portion of the detection cycle that follows the transmit portion of the detection cycle; and determining the presence or absence of a transponder by the processor circuit based at least in part on a number M of samples or measurements of the electromagnetic signals received during the detection cycle and the adjusted signal detection threshold, where the number M is greater than one.