| 摘要 |
PURPOSE: To make sampling frequency changeable by a large margin while the cut-off frequency of an aliasing preventing filter is as it is fixed at the time of measuring a transfer function or the like between a digital signal system and an analog signal system. CONSTITUTION: At the time of measuring a transfer function of an analog circuit 28, frequency Fsa for sampling its analog output is made higher than sampling frequency Fsd of a digital system. When the cut-off frequency of an aliasing preventing filter 30 is made FLP, and frequency to be observed is made 0-Fspan , the frequency ratio of a left side is set in such a way as to obtain Fsa/Fsd>=(Fspan +FLP)/Fsdo . A measured result uninfluenced by aliasing is thereby obtained. |
