Patent ID: 7014112
Filing Date: 2006-03-21
Classification: G06K

Abstract:
1. A method of conveying information from an electronic identification label to an interrogator, comprising: coupling energy from an external field to a resonant circuit of the electronic identification label; the electronic identification label periodically storing and discharging an amount of the coupled energy; and wherein the period of the storing and discharging conveys information about the electronic identification label to the interrogator; coupling energy from the external field into a second resonant circuit of the electronic identification label; and the electronic identification label periodically storing and discharging an amount of the energy coupled into the second resonant circuit, wherein the period during which the electronic identification label stores and discharges the energy coupled into the second resonant circuit conveys timing information to the interrogator that accompanies the information about the electronic identification label, wherein the information about the electronic identification label is measured by way of measuring a change in the input impedance to a first field-generating device operating at a first frequency, and wherein the timing information is measured by way of measuring a change in the input impedance to a second field-generating device operating at a second frequency.