Sensor system for determining the properties of a transmission path between a transmitter and a receiver or for determining an object in the transmission path, wherein the sensor system is based on a feedback control, comprising - the transmitter, which is triggered with a transmission feed signal and transmits a transmission signal into the transmission path, - the receiver, which receives the transmission signal transmitted by the transmitter after passing through the transmission path or after passing through the transmission path and being influenced by the object in the transmission path, and outputs a receiver output signal, - a compensation unit, which is fed with a compensation feed signal and generates a compensation signal superimposing the receiver output signal, - a processing unit for further processing the receiver output signal and for generating a control value signal, - a signal generation unit, which generates the transmission feed signal or the compensation feed signal, - a reverse transformation unit, which performs a reverse transformation with the control value signal or with a further processed control value signal, wherein - the reverse transformation is a transmission reverse transformation and generates the transmission feed signal when the compensation feed signal is generated in the signal generation unit, or - the reverse transformation is a compensation reverse transformation and generates the compensation feed signal, which is fed into the compensation unit when the signal generation unit generates the transmission feed signal, wherein - the control value signal is a measure for a property of the transmission path and/or the object in the transmission path, characterized in that - the receiver is a drift field diode into which an element of the processing unit is integrated, - the drift field diode comprises a doping gradient generated by a doping profile so that a space-charge region is generated which can be modulated by an electrostatic field, - the modulation of the space-charge region of the drift field diode is carried out by the transmission feed signal if the signal generation unit generates the transmission feed signal, or by the compensation feed signal if the compensation feed signal is generated in the signal generation unit, and in that the sensitivity of the drift field diode can be controlled via the modulation; and - the element of the processing unit integrated into the drift field diode is a linear form and the linear form of the processing unit is a multiplication unit. - the transmitter, which is triggered with a transmission feed signal and transmits a transmission signal into the transmission path, - the receiver, which receives the transmission signal transmitted by the transmitter after passing through the transmission path or after passing through the transmission path and being influenced by the object in the transmission path, and outputs a receiver output signal, - a compensation unit, which is fed with a compensation feed signal and generates a compensation signal superimposing the receiver output signal, - a processing unit for further processing the receiver output signal and for generating a control value signal, - a signal generation unit, which generates the transmission feed signal or the compensation feed signal, - a reverse transformation unit, which performs a reverse transformation with the control value signal or with a further processed control value signal, wherein - the reverse transformation is a transmission reverse transformation and generates the transmission feed signal when the compensation feed signal is generated in the signal generation unit, or - the reverse transformation is a compensation reverse transformation and generates the compensation feed signal, which is fed into the compensation unit when the signal generation unit generates the transmission feed signal, wherein - the reverse transformation is a transmission reverse transformation and generates the transmission feed signal when the compensation feed signal is generated in the signal generation unit, or - the reverse transformation is a compensation reverse transformation and generates the compensation feed signal, which is fed into the compensation unit when the signal generation unit generates the transmission feed signal, - the control value signal is a measure for a property of the transmission path and/or the object in the transmission path, - the receiver is a drift field diode into which an element of the processing unit is integrated, - the drift field diode comprises a doping gradient generated by a doping profile so that a space-charge region is generated which can be modulated by an electrostatic field, - the modulation of the space-charge region of the drift field diode is carried out by the transmission feed signal if the signal generation unit generates the transmission feed signal, or by the compensation feed signal if the compensation feed signal is generated in the signal generation unit, and in that the sensitivity of the drift field diode can be controlled via the modulation; and - the element of the processing unit integrated into the drift field diode is a linear form and the linear form of the processing unit is a multiplication unit.