Abstract: An FM receiver includes an IF unit followed by an LF unit, the IF unit having an IF filter arrangement. The center frequency of the IF filter arrangement, which is relatively narrow-banded with respect to the channel bandwidth, is controlled in dependence on the receiving conditions. The receiver has circuitry for changing the signal transmission characteristic of the IF and/or LF units, including a detector module with detector circuits for detecting values characteristic of receiving or interference states, with the inputs of said circuits each being connected with a circuit point of the IF or LF unit carrying the signal to be processed, and with the outputs of these circuits providing signals characterizing receiving and interference states.

Abstract: An FM receiver includes an IF unit followed by an LF unit, the IF unit having an IF filter arrangement. The center frequency of the IF filter arrangement, which is relatively narrowbanded with respect to the channel bandwidth, is controlled as a function of receiving conditions. The receiver has circuitry for changing the signal transmission characteristic of the IF and/or LF unit, including a detector module for detecting signals characterizing various receiving states, a signal processing unit which changes the amplitude or the time values of signals from the detector module, and a signal linkage unit to create output signals by way of logic and/or time dependent linkage of signals outputted by the signal processing unit.

Abstract: An FM receiver includes an IF unit followed by an LF unit. The receiver has circuitry for changing the signal transmission characteristic of the IF and/or LF units, including a detector module with detector circuits for detecting values characteristic of receiving or interference states, with the inputs of these detector circuits each being connected with a circuit point of the IF or LF unit carrying the signal to be processed and with the outputs of these detector circuits providing signal characterizing receiving the interference states.

Abstract: In an FM receiver where the center frequency of an IF filter is varied depending on the received signal, an arrangement is described in which the passband of the retuned IF filter is selected so that a distinct resonance region having a relatively steep-edged drop of at least 6 dB exists in the middle of the channel; a less steep or level curve exists in a region essentially symmetrically spaced from the middle of the channel on both sides of the resonance region; and the pass limits lie essentially in symmetry with the middle of the channel.