Apparatus for identifying objects and persons
First Claim
1. In an identification system having an information carrier secured to an object to be identified and a read unit connected with the latter via electromagnetic waves, the information carrier comprising an antenna system, a plurality of passive elements connected in a plurality of branch circuits, at least the inputs of said branch circuits being connected in common, and matching circuit, connected between said common connection and said antenna system, said passive elements comprising delay elements having different defined delay times, transducers connected with said delay elements with defined frequencies and bandwith for driving said delay elements, and attenuation elements having defined attenuation characteristics, and a common carrier member for carrying said passive elements.
0 Assignments
0 Petitions
Accused Products
Abstract
A system for identifying persons and objects includes an information carrier adapted to be secured to an object to be identified, and a read unit coupled to the information carrier by means of electromagnetic waves. The information carrier incorporates a plurality of passive elements interconnected with a receive-transmit antenna system so that an interrogation signal is processed and retransmitted as a unique signature of the information carrier. The passive elements of the information carrier include delay elements, attentuation elements, and filters, interconnected in a plurality of parallel paths to generate the identifying signature.
-
Citations
23 Claims
- 1. In an identification system having an information carrier secured to an object to be identified and a read unit connected with the latter via electromagnetic waves, the information carrier comprising an antenna system, a plurality of passive elements connected in a plurality of branch circuits, at least the inputs of said branch circuits being connected in common, and matching circuit, connected between said common connection and said antenna system, said passive elements comprising delay elements having different defined delay times, transducers connected with said delay elements with defined frequencies and bandwith for driving said delay elements, and attenuation elements having defined attenuation characteristics, and a common carrier member for carrying said passive elements.
-
23. In an identification system having an information carrier secured to an object to be identified and a read unit for interrogating said information carrier by means of an electromagnetic interrogation signal, an information carrier comprising receiver means for receiving said interrogation signal, a plurality of branch circuits connected to said receiver means for processing said interrogation signal, each of said branch circuits having delay means for introducing a different predetermined delay and at least one of said branch circuits having attenuation means for attenuating said interrogation signal, and transmitting means for combining signals processed in all of said branch circuits and for transmitting said combined signals as an electromagnetic composite signal.
Specification