| 摘要 |
PURPOSE:To ensure the steady and variable adjustment for the attenuation quantity to the signal component in the fixed frequency range, by istalling in parallel the BPF's featuring the slope cut-off properties of 12dB and 6dB oer octave respectively into the negative feedback path. CONSTITUTION:Inputsignal 12 is applied to subtractor SUB as the reduced signal, and the output signal given from SUB is amplified (AMP) to be given to output terminal 13. And the output signal is then negatively fed back to SUB via the parallel circuit of first BPF1 and second BPF2. BPF1, consisting of the series circuit of primary HPF1 of cut-off frequency fh and primary LPF1 of cut-off frequency f, shows such pass band characteristics that the slope of the frequency response characteristics curve may be 6dB per octave from the pass band through he cut-off region. While BPF2 features the similar constitution to BPF1 and shows the pass band characteristics of 12dB fer octave. |
