Microwave identification system
First Claim
1. A microwave identification system comprising:
- interrogation transmitter/receiver means and an interrogation antenna system for transmitting an interrogation electromagnetic field and receiving responsive electromagnetic waves;
a plurality of responders each including a responder antenna system for communicating with the interrogation transmitter/receiver means, each of said responders being responsive to the interrogation electromagnetic field to generate responsive electromagnetic waves, the responder antenna system comprising an antenna array having at least first and second transmitting/receiving antenna elements and modulation means interconnecting the first and second transmitting/receiving antenna elements, the first and second transmitting/receiving antenna elements being responsive to the interrogation electromagnetic field to generate at least first and second antenna output signals, respectively, the modulation means responsive to the first and second antenna output signals for generating at least first and second modulated output signals which are encoded with a responder code that is particular to the associated responder, and the modulation means applying the first and second modulated output signals to the second and first antenna elements, respectively.
1 Assignment
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Accused Products
Abstract
A microwave identification system comprising a transmitter/receiver provided with an antenna system, a plurality of responders provided with an antenna system, the communication between transmitter/receiver and responders taking place by means of electromagnetic waves in the microwave range, wherein the antenna system of the responders comprises an array with at least two antenna elements (12, 13) interconnected via a modulation device (14, 15, 16) and, for obtaining a retroreflective effect, the signal generated in an interrogation field by one of the two antenna elements is applied to the modulation device and, after being modulated with a code that is characteristic for the responder, is applied to the other antenna element to be radiated by the other antenna element.
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Citations
14 Claims
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1. A microwave identification system comprising:
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interrogation transmitter/receiver means and an interrogation antenna system for transmitting an interrogation electromagnetic field and receiving responsive electromagnetic waves; a plurality of responders each including a responder antenna system for communicating with the interrogation transmitter/receiver means, each of said responders being responsive to the interrogation electromagnetic field to generate responsive electromagnetic waves, the responder antenna system comprising an antenna array having at least first and second transmitting/receiving antenna elements and modulation means interconnecting the first and second transmitting/receiving antenna elements, the first and second transmitting/receiving antenna elements being responsive to the interrogation electromagnetic field to generate at least first and second antenna output signals, respectively, the modulation means responsive to the first and second antenna output signals for generating at least first and second modulated output signals which are encoded with a responder code that is particular to the associated responder, and the modulation means applying the first and second modulated output signals to the second and first antenna elements, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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Specification