Patent ID: 7221259
Filing Date: 2007-05-22
Classification: G06K,G08B

Abstract:
1. A system for electromagnetically interrogating electronically coded labels, said system comprising: an interrogator, said interrogator containing a generator of electromagnetic interrogation signals and a receiver of electromagnetic ambient signals, wherein said ambient signals are not generated by said interrogator; at least one electromagnetically interrogatable electronic coded label adapted to receive said interrogation and said ambient signals, said at least one label containing a rectifier for obtaining operating power for said label from said interrogation and said ambient signals; wherein said rectifier is adapted to make use of said ambient signals to obtain said power at least when said interrogator is not generating said interrogation signals; wherein said ambient signals received by said receiver are used by said interrogator as reference signals in detecting a label reply, and wherein said interrogator includes an antenna system in which some elements contribute to generation of an electromagnetic field at a position of electromagnetic compatibility testing, and a different set of elements generate an electromagnetic field in a region wherein coded labels are located.