VERFAHREN ZUR VERMEIDUNG VON STÖRAUSSTRAHLUNGEN BEI AM-SENDERN FÜR DIGITALE ÜBERTRAGUNG

摘要

A method for avoiding spurious emissions in an AM transmitter for digital transmission includes converting a digital modulation for controlling the AM transmitter into an amplitude signal and a phase-modulated RF signal. Non-linear distortions in an amplitude response and a delay-time characteristic of an amplitude branch are compensated for using a pre-equalization with inverse shapes by: measuring and storing the amplitude response and the delay-time characteristic of an amplitude branch; determining an inverse transfer function using respective shapes of the measured amplitude response and delay-time characteristic by an inverse Fourier transform; dimensioning an equalizing network for the determined inverse transfer function; and connecting the equalizing network in series upstream of the amplitude branch. An equalizing network is dimensioned for the determined inverse transfer function. The equalizing network is connected in series upstream of the RF branch.