| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem that costs for an apparatus is increased since in an active shield, a buffer amplifier operating stably in a wide frequency band is required in the drive circuit in order to stably obtain the suppressing effect of a measurement error by the active shield. <P>SOLUTION: In a shielded cable, the output voltage of the drive circuit can be reduced in a prescribed frequency band required for measurement by adjusting the frequency characteristic of a band restriction circuit added to the drive circuit between a core wire and a shield. As the result of this, in the prescribed frequency band, the function of the active shield can be degraded. Consequently, the buffer amplifier only has to correspond to the frequency band except the prescribed frequency band (including a band required for measurement), thereby a low-cost active shield can be constituted by using an inexpensive buffer amplifier. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
