| 摘要 |
<p>PURPOSE:To measure a relative delay by one test by impressing first and second test signals synchronously on the respective ends of first and second transmission channels respectively and by forming a delay difference signal by combining these test signals with each other. CONSTITUTION:When test signals T1 and T2 are impressed on transmission channels, a difference signal DS is generated at the output of a difference detec tor. First, in a first section of the difference signal DS, a waveform SD which is a difference (SS1-SS2) of sweep signals appears in a period I2. When the difference is zero, this waveform SD becomes a flat line of 0 volt. When there is a relative delay, the waveform SD becomes a sine wave having an envelope EV3 of frequencies rising continuously. A size X at an arbitrary point in a period I3 of this envelope EV3 relates to the size of a delay difference at a sweep frequency fx to which it corresponds. It is a delay marker DM1, for instance, in a section following the above that scales the size X of the envelope EV3 in a delay time, and this marker is obtained from a difference between a first marker component DM1a and a second marker component DM1b corre sponding thereto.</p> |
