| 摘要 |
<p>A filter apparatus (1) has a digital FIR filter (8) divided into two or more sections (6, 12) with means (18, 20, 22, 24, 26, 40) for varying the filter function of each section (6, 12). The filter (1) has an input switch means (2, 4) and an output switch means (28, 30, 32) which includes a fader means (28, 30, 32) to enable one or more sections (6, 12) to be switched out of circuit without disrupting the passage of signals to be filtered through the other section or sections (6, 12) of the filter (8). The filter function of each section (6, 12) is adjustable when the section (6, 12) is switched out of circuit.</p> |
