The present invention relates to an electromagnetic mixing system for receiving and processing modulated electromagnetic signals, with a signal detector made from a semiconductor material for receiving and converting electromagnetic radiation into an electric measured value and with at least one modulation input modulating the reception of the signal detector, and also with at least two accumulation electrodes which are connected to output electronics at the output of which a mixture of the received signal and at least one modulation signal applied at the modulation input is effectively provided as electric signal. The present invention also relates to a method for operating such an electromagnetic mixing system, the electromagnetic signals striking the signal detector producing charge carriers which, depending on the at least one modulation signal, are conducted at least partially alternately to the at least two different readout electrodes. In order to create a system and a method which also delivers correct mixer results in the case of geometric or electric asymmetries of the PMD elements, i.e. measurement signals based exclusively on the coherent radiation, it is proposed according to the invention that apparatuses for modifying parameters of the at least one modulation signal are provided such that by modifying these parameters the output signal is different from a zero signal only if the modulations of the received electromagnetic radiation signal and the at least one modulation signal are correlated with each other. As regards the method, it is proposed that the signals derived from the accumulation electrodes and entered [by] the output electronics are varied such that the output signal assumes a value different from the zero signal only if the at least one modulation signal and the modulated electromagnetic reception signal are correlated with each other.