Abstract: A RC coupling filter, especially an input filter for receivers of centralized ripple control systems, with at least two similar active RC four terminal networks with at least one amplifier each, each four terminal network having an input and every two adjacent RC four terminal networks being interconnected by means of exactly one coupling admittance connected between the inputs of the adjacent RC four terminal network, wherein, if the signal to be filtered is introduced into the input of the first RC four terminal network, a feeding admittance is connected at one end to the input of the first RC four terminal network, the signal to be filtered being introduced into the other end of the feeding admittance.