Interrogation, and detection system
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsHoward A. Baldwin, Steven W. Depp, Alfred R. Koelle, Robert W. Freyman
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Abstract
The specification relates to a telemetering apparatus comprising a generator which generates at least a single frequency rf signal, a transponder for receiving that signal and for amplitude modulating it in accordance with information selected for transmission, an antenna on the transponder for reflecting the amplitude modulated signal, and a receiver which is preferably located at the generator. The receiver processes the signal to determine the information carried thereby.
Claims10
In telemetry apparatus, a passive transponder comprising:
- an antenna;
- rectifier means having a first pair of terminals connected to said antenna and having a second pair of terminals providing direct current;
- variable loading means connected to said second pair of terminals;
- and
- information encoding means in circuit with said variable loading means to enable encoded information to vary the direct current drawn from said rectifier by said variable loading means, thereby varying the impedance of said rectifier means at said first pair of terminals, and varying the reflectivity of said antenna.
A passive transponder adapted to be implanted beneath the skin of a living animal, comprising:
- an antenna;
- a voltage doubling rectifier having first and second terminals connected to said antenna, and having third and fourth terminals;
- an audio frequency oscillator;
- a temperature sensitive resistor connected to said audio oscillator to vary the frequency of said audio oscillator in response to ambient temperature changes;
- variable rectifier loading means including a resistor connected to said third terminal, a transistor having a collector connected to said resistor, an emitter connected to said fourth terminal, and a base electrode connected to said audio frequency oscillator.
Dependencies are inferred from the claim text.