Patent ID: 7772977
Filing Date: 2010-08-10
Classification: G01S,G06K,G07B,H04B,Y10T

Abstract:
1. A transponder for receiving an interrogation signal from a reader at a first frequency and sending a response signal from the transponder at a third frequency, while mitigating interference effects from an interfering signal at a second frequency, the transponder comprising: an antenna for receiving the interrogation signal from the reader; a detector in communication with the antenna, said detector detecting the interrogation signal and outputting a baseband analog signal representing the interrogation signal; a frequency-selective filter comprising a low-pass filter in communication with the detector to receive the baseband analog signal output by the detector, said frequency-selective filter performing frequency-selective filtering of the baseband analog signal to output an analog signal with reduced interference; and a signal processor in communication with the frequency-selective filter to receive the analog signal with the reduced interference, said signal processor processing the analog signal with the reduced interference to extract information from the analog signal with the reduced interference; wherein the low-pass filter has a cutoff frequency which is less than a difference between the first frequency and the second frequency.