Filter circuit with frequency adjustment

摘要

The circuit arrangement contains a band pass filter (3) which is supplied with an input signal (I). The band pass filter has a controllable pass frequency range and provides a filtered output signal (0) at its output. A phase detector (4) is provided, which mixes the input signal with the filtered output signal. A signal from the phase detector is passed to the band pass filter (3) over a low pass filter (5), for controlling the pass frequency range. The frequency of the band pass filter (3), at which its suppression is minimal, is pref. controllable.