Patent · US Expired

Method for the testing of an inductive resonant circuit

US6236220A · kind A · utility

9Cited by
5References
26Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 17, 1998
Grant dateMay 22, 2001
Priority date
Expiry dateNov 17, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B17/12
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A method for testing whether an antenna circuit of a contactless chip card is defective. The antenna circuit is an inductive resonant circuit comprising a capacitor and an antenna coil. The antenna coil of the resonant circuit is excited by inductive coupling using a test coil wherein the excitation is then sharply interrupted. By detecting in the test coil a response signal generated by self-induction in the antenna coil of the resonant circuit and retransmitted to the test coil by inductive coupling, the response signal can be analyzed for determining whether a contactless chip card is defective. Application is well suited to the testing of antenna circuits for electronic portable devices working without contact, such as contactless chip cards, electronic labels, etc.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.