| 摘要 |
1449477 Alternating crosstalk in transmission lines SIEMENS AG 18 Dec 1973 [18 Dec 1972] 58599/73 Heading H4R A PCM transmission system includes a line divided longitudinally into sections each having a screened GO and screened RETURN bunch of wire pairs Z1-Z5 of which at least some have discrete inductive elements F of such type and longitudinal spacing that longitudinal currents in excess of 4MHz are attenuated. The elements F are ferrite sleeves located at each side of soldered joints L between line lengths and may be of different characteristics to encompass a broader frequency range and staggered disposition to reduce the cross-sectional area. The wire pairs may have a different strand pitch to further reduce far-end cross talk. Where the pairs form quads the sleeves may be around the individual pairs or the quad. A mathematical formula is given by which to calculate the size and inductance of the elements F. |
