Identification system with vector phase angle detection
First Claim
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1. An electronic recognition and identification system comprising:
- a recognition section including an oscillator, a reader antenna means connected to said oscillator and a power supply for radiating electromagnetic power responsive to said oscillator, an amplifier connected intermediate said oscillator and said reader antenna for amplifying the signal from said oscillator, a transistor connected intermediate said amplifier and said reader antenna to control the flow of power from said supply to said reader antenna, detection means comprising a phase shifter connected to said oscillator to modify the signal from said oscillator and a phase comparator connected to said phase shifter and to said reader antenna to compare the phase angles of the signals from said phase shifter and said reader antenna and for delivering output signals responsive to said changes in vector phase angle, and a filter connected to the output of said phase comparator, said filter being joined to an amplifier and clamp such that the output from the recognition section is in the form of logic data; and
an identification section having an identifier antenna for receiving power from said reader antenna by mutual coupling, a reactance modulation circuit connected to the identifier antenna, a tap on said identifier antenna to tap the voltage across a portion of said identifier antenna, rectifier means intermediate said tap and a data register means, and said data register means comprising a clock and a memory system for providing an advance and sequence of data joined to said reactance modulation circuit, such that the vector phase angle of the current of said modulation circuit varies responsive to said sequence of data.
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Abstract
An electronic identification and recognition system which detects vector phase angle changes. The recognition section radiates power to the identification section. The phase angle of the current in the identifier antenna is determined by a clock and memory system which varies the reactance of the identifier antenna circuit. The change in reactance affects the phase angle of the voltage within the reader antenna. The phase angle changes are detected and recorded by the recognition section such that the internal code of the identifier section is determined.
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9 Claims
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1. An electronic recognition and identification system comprising:
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a recognition section including an oscillator, a reader antenna means connected to said oscillator and a power supply for radiating electromagnetic power responsive to said oscillator, an amplifier connected intermediate said oscillator and said reader antenna for amplifying the signal from said oscillator, a transistor connected intermediate said amplifier and said reader antenna to control the flow of power from said supply to said reader antenna, detection means comprising a phase shifter connected to said oscillator to modify the signal from said oscillator and a phase comparator connected to said phase shifter and to said reader antenna to compare the phase angles of the signals from said phase shifter and said reader antenna and for delivering output signals responsive to said changes in vector phase angle, and a filter connected to the output of said phase comparator, said filter being joined to an amplifier and clamp such that the output from the recognition section is in the form of logic data; and an identification section having an identifier antenna for receiving power from said reader antenna by mutual coupling, a reactance modulation circuit connected to the identifier antenna, a tap on said identifier antenna to tap the voltage across a portion of said identifier antenna, rectifier means intermediate said tap and a data register means, and said data register means comprising a clock and a memory system for providing an advance and sequence of data joined to said reactance modulation circuit, such that the vector phase angle of the current of said modulation circuit varies responsive to said sequence of data. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification