| 摘要 |
<p>PURPOSE:To always secure the optimum filter degree by securing variation for the width of the pass and the central frequency and at the same time securing a fixed ratio between the band rise band and the sampling frequency regardless of the above mentioned variation. CONSTITUTION:The signals of input terminal 11 are supplied to the 1st-step delay unit D1 among delay units D1-DN-1 which give delay to sampling cycle T of the signals, and at the same time the output of units D1-DN-1 is supplied to multipliers MO-MN-1. The output of these multipliers is added through adder 12, and the filter output is delivered to output terminal 13. In such constitution, multipliers MO-MN-1 are constituted so that multiplier h(nT) may be varied, and the setting unit such as a digital switch or the like is provided to secure setting of central frequency fO of the pass band and cut-off frequency fC. And the operation of the formula is carried out when frequency fO and fC set by the setting unit are supplied along with the tap number, thus securing the optimum filter degree.</p> |
