Low voltage signal stripping circuit for an RFID reader
First Claim
1. A method for processing a high voltage antenna signal waveform comprising the steps of:
- providing a high voltage antenna signal waveform including a low voltage transponder signal containing readable information superposed on a high voltage excitation signal;
specifying a location on said waveform where a waveform portion is to be isolated;
specifying a size of said waveform portion to be isolated at said specified location on said waveform;
isolating said waveform portion, wherein said waveform portion contains said readable information; and
reading said readable information on said waveform portion.
3 Assignments
0 Petitions
Accused Products
Abstract
A reader of an RFID system has excitation circuitry for generating a higher voltage excitation signal, receiving circuitry for reading a lower voltage transponder signal and an antenna coupled with the excitation circuitry for transmitting the excitation signal and coupled with the receiving circuitry for receiving the transponder signal. The receiving circuitry includes a low voltage signal stripping circuit coupled with the antenna for isolating the transponder signal from the excitation signal preliminary to the receiving circuitry reading the transponder signal. The bulk of the components of the low voltage signal stripping circuit are low voltage components, which can be included in an application specific integrated circuit.
34 Citations
20 Claims
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1. A method for processing a high voltage antenna signal waveform comprising the steps of:
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providing a high voltage antenna signal waveform including a low voltage transponder signal containing readable information superposed on a high voltage excitation signal;
specifying a location on said waveform where a waveform portion is to be isolated;
specifying a size of said waveform portion to be isolated at said specified location on said waveform;
isolating said waveform portion, wherein said waveform portion contains said readable information; and
reading said readable information on said waveform portion. - View Dependent Claims (2, 3)
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4. A method for processing a high voltage antenna signal comprising the steps of:
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receiving a high voltage antenna signal containing readable information from an antenna at an input of a low voltage stripping circuit;
limiting a voltage of said high voltage antenna signal to create a low voltage output signal containing said readable information;
creating a DC shift voltage or a DC shift current;
selectively distributing a feedback signal from an amplifier having an output operating range; and
creating a summed signal containing said readable information by summing said low voltage output signal, said selectively distributed feedback signal, and said DC shift voltage or said DC shift current. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for processing a high voltage antenna signal comprising the steps of:
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receiving a high voltage antenna signal containing readable information from an antenna at an input of a low voltage stripping circuit;
limiting a voltage of said high voltage antenna signal to create a low voltage output signal containing said readable information;
creating a DC shift voltage or a DC shift current;
selectively distributing a feedback signal from an amplifier having an output operating range, wherein said feedback signal is selectively distributed by a feedback circuit having a first pathway with a low impedance to said feedback signal when a voltage of said feedback signal is above an upper limit of a predetermined voltage range, a second pathway with a low impedance to said feedback signal when said voltage of said feedback signal is below a lower limit of said predetermined voltage range, and a third pathway with a low impedance to said feedback signal when a voltage of said feedback signal is within said predetermined voltage range; and
creating a summed signal containing said readable information by summing said low voltage output signal, said selectively distributed feedback signal, and said DC shift voltage or said DC shift current. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification