Patent ID: 8797163
Filing Date: 2014-08-05
Classification: G06K

Abstract:
1. A method for transferring data from a transponder unit of a portable data carrier to a reading device which receives data from transponders by load modulation of a field of the reading device, comprising the steps: the transponder unit, in a first operating mode, generating a modulated transponder field and emitting the modulated transponder field containing the data to be transferred as a first signal which emulates load modulation of the reading device field by a transponder, wherein a ring modulator of the transponder unit suppresses a carrier frequency signal generated by an oscillator of the transponder unit in favor of a subcarrier signal modulated with the data to be transferred by supplying the carrier frequency into a first input end of the ring modulator and by supplying the subcarrier signal modulated with the data to be transferred into a second input end of the ring modulator, wherein the transponder unit in a second operating mode performs load modulation for transferring the data to the reading device, wherein in the second operating mode the field of the reading device is loaded by the transponder unit and a second signal containing the data to be transferred from the transponder unit is received through coupled modulation of the field of the reading device, and wherein the portable data carrier is a chip card.