Planar Resonance Circuits for Identity Documents or Banknotes Authentication

This paper deals with the design and realization of planar resonance circuits, which are part of a system designed to verify the authenticity of identity documents or banknotes. Validation or authentication is performed based on the evaluation of resonance frequency changes due to the size and location of security protection elements in the form of holographic or other metallic security structures located on identity documents or banknotes. Different types of planar resonance circuits have been designed for this system, and suitable placement of safety elements has been proposed with regard to the evaluable changes in resonance frequencies.