The invention relates to a preamplifier circuit with at least one transistor that couples a signal input to a signal output. The signal input is supplied with a radio-frequency signal. In addition, the preamplifier circuit includes a switch that switchably couples the input to a reference potential and which, when the preamplifier is inactive, is closed. Hence, when the preamplifier is inactive, the input is put into a low-impedance state and the amplifier and downstream assemblies are protected from unwanted high-power interference signals. It is thus also possible to use other, fully integratable filter types in a transceiver's reception signal processing chain instead of external surface acoustic wave filters with a low level of complexity and without drawbacks.