Integrierbarer Schaltermodulator

An integratable switch modulator for multiplying an input signal by a binary carrier signal generates its output signal by alternately weighting the input signal with a positive and a negative factor at the same rate as the binary carrier signal and comprises an operational amplifier and electronic switches controlled by the carrier signal. In order to increase the signal to noise ratio of the output signal, the inverting input of the operational amplifier is connected to its output via a first resistor and to a first and second switch via a second resistor, the first of the switches being connected to a reference potential and the second being connected to a switch modulator input, whereas the non-inverting input of the operational amplifier is connected to the reference potential via a third resistor and to a third and fourth switch via a fourth resistor, the third of the switches being connected to the switch modulator input and the fourth being connected to the reference potential, whereby the switches are controlled by the carrier signal in such a way that either the first and third or the second and fourth switches are open, and the resistance values of the resistors satisfy the following equation: Formula 1, where RS is the continuity resistance of the closed switches S1, S3.