| 摘要 |
<p>The noise removal device includes a noise detection circuit (5) comprising a highpass filter (51), a wave detector (52) and a voltage comparator (53). A path for the input signal (S1) includes a variable lowpass filter (2) permitting the cutoff frequency to be varied and outputs signals that have passed through this filter. A 2nd signal path for input signals includes, e.g., a variable phase shifter (1). A control circuit (4) varies the lowpass filters cutoff frequency in accordance with the input signal frequency. A selector (3) selects output signals (S2) from the 1st path when noise is detected by the noise detection circuit (5).</p> |
