| 摘要 |
PURPOSE:To realize a sufficient filter characteristic with a small number of transfer stages, by setting the relation between the number of cycles of the weight coefficient, which is included in the filter in one system, and the passage center frequency as a filter to a prescribed relation. CONSTITUTION:Arrangement of transfer electrodes 101, 102, 103... is set to a length corresponding to, for example, the double of pattern cycle P, and repeat frequency ft of the pulse train for transfer applied to the filter is selected, for example, as six times as high as passage center frequency fc. When a unit impulse wave is applied to this filter as the input and the impulse response is smoothed, a sine-wave burst signal with wave continuity length 2T is obtained. This waveform is subjected to Fourier conversion to obtain the frequency characteristic of this filter. That is, this filter has a characteristic to cut off completely frequencies 0.5fc and 1.5fc. |
