Optical interface between receiver and tag response signal analyzer in RFID system for detecting low power resonant tags
First Claim
1. In a radio frequency identification (RFID) system having a detection zone for detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag,(a) a receiver circuit which outputs a demodulated analog tag response signal upon detection of the intelligent tag in the detection zone;
- (b) a tag response signal analyzing circuit including(i) an input, and(ii) a digital signal processing circuit which processes the analog tag response signal and outputs therefrom intelligent tag data; and
(c) an optical interface connected at one end to the output of the receiver circuit and connected at the other end to the input of the tag response signal analyzing circuit for communicating the analog tag response signal from the receiver circuit to the tag response signal analyzing circuit.
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Accused Products
Abstract
Noise reduction schemes are provided in a radio frequency identification (RFID) system for use with RFID intelligent tags. Fiber optics are used to communicate analog tag response signals from the output of the receiver circuit to the input of a tag response signal analyzing module, which includes a digital signal processor (DSP). The fiber optics creates electrical isolation between these circuit elements breaking ground loops, stopping internal switching noise from the DSP from entering the receiver circuitry, and preventing common mode signals from interfering with the desired RFID tag signal.
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Citations
4 Claims
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1. In a radio frequency identification (RFID) system having a detection zone for detecting the presence of an article in the detection zone wherein the article is tagged with a resonant intelligent tag,
(a) a receiver circuit which outputs a demodulated analog tag response signal upon detection of the intelligent tag in the detection zone; -
(b) a tag response signal analyzing circuit including (i) an input, and (ii) a digital signal processing circuit which processes the analog tag response signal and outputs therefrom intelligent tag data; and (c) an optical interface connected at one end to the output of the receiver circuit and connected at the other end to the input of the tag response signal analyzing circuit for communicating the analog tag response signal from the receiver circuit to the tag response signal analyzing circuit. - View Dependent Claims (2, 3, 4)
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Specification