Method for influencing signal form of output signal of high frequency-amplifier of active load-modulating data carrier used with reading device, involves controlling output oscillating circuit with frequency that deviates from basic signal

摘要

The method involves amplifying a modulated basic signal of a fundamental frequency. The basic signal is used as a driver signal for excitation of an output oscillating circuit (62) i.e. antenna. The oscillating circuit is tuned to a frequency in a range of the fundamental frequency and excited by the basic signal in a normal operation. The circuit is controlled with the frequency, which deviates from the basic signal, at preset time points such that the circuit is detuned. The deviating frequency is switched with the fundamental frequency of the basic signal after a transmission process. An independent claim is also included for a portable data carrier.