| 摘要 |
PURPOSE:To reduce noises of a filter output and to improve a selection degree by constituting a digital filter of N-number of multipliers, adders and delay circuits and precessing outputs of quantized error components form the outputs of the 1-Nth multipliers to the filter outputs with the prescribed relationship. CONSTITUTION:The digital filter is constituted of N-number of the multipliers 100-109, the adders 200-205 and the delay devices 300-303, and an input signal from an input terminal 400 is outputted to an out put terminal 500. Where a transmission function employing Z-convertion from the output of i-numbered (i: any one among 1-N) multiplier among the multipliers 100-109 to the terminal 500 is assumed to be Pi(Z)/Qi(Z), the transmission function where the quantized error component in the transmission function where the quantized error component in the output of the i-numbered multiplier lies up to the terminal 500 is set to be Pi(Z)(Ai(Z)-1/Qi(Z)). Then the noise component of the filter output from the terminal 500 is reduced, and the selection degree Q of the filter is improved.
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