Infineon Technologies Ag

Volker G&uuml;ngerich

Robert Reiner

Gerhard Schraud

Doris Schmitt-Landsiedel

Uwe Weder

Gerhard Nebel

Andreas Blum

Dierk Eichner

A data carrier includes at least one coil for the contactless reception of amplitude-modulated signals. A rectifier circuit is connected downstream of the coil. A circuit configuration processes and/or stores data. A supply-voltage control circuit is connected in parallel with the circuit configuration. A current measuring device acts as an amplitude demodulator and is disposed between the coil and the voltage-supply control circuit.

Data carrier for the contactless reception of amplitude-modulated signals

A method for demodulating a voltage which has been ASK modulated by changing the amplitude between a low level and a high level, in particular for use during contactless data transmission from a card reader/writer to a smart card, is described. The method is distinguished, in that, in an initialization phase, a first mean value is produced from the high voltage level and a stored partial voltage derived therefrom in order to detect a change to a low voltage level. The change to the low voltage level represents a start value and is detected by a subsequent comparison of the modulated voltage with the first mean value. In a subsequent demodulation phase, a second mean value is produced from the detected low voltage level and the high voltage level in order to demodulate the modulated voltage by comparing the modulated voltage with the second mean value.

Method for ASK demodulation, and ASK demodulator

Growing community of inventors

München, Germany

Volker Güngerich

Growing community of inventors

München, Germany

Volker G&uuml;ngerich

Volker Güngerich