| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a filter device which can obtain a Chamberlin filter coefficient with excellent frequency characteristics in a simple arrangement. <P>SOLUTION: In this filter device, a Chamberlin filter 300 filters an inputted digital tone signal with filtering characteristics according to a set filter coefficient, and a coefficient calculator 200 obtains a filter coefficient to be set to the filter 300. The coefficient calculator 200 obtains a first parameter as a cutoff frequency value (Fc), and a second parameter as a resonance value (Q) to directly obtain two filter coefficients (F and W) by equations "F=(1+Q)Fc and W=(1-Q)(2-Fc)"; and the obtained filter coefficients (F and W) are set to the filter portion 300. Thus, a filter device of a simple arrangement which requires no coefficient table and complementary calculation can be realized. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
