Printed circuit board and signal transmission apparatus thereof

A printed circuit board (PCB), comprising:

• a differential pair comprising two transmission lines arranged side by side;
• a filter section arranged in the differential pair to filter noise of signals transmitted through the differential pair;
• wherein
• a distance between the two transmission lines changes with desired frequency bandwidth and desired frequency response of the differential pair.

A printed circuit board comprising:

• a signal layer, wherein a differential pair comprising two transmission lines is arranged in the signal layer, the differential pair comprises a filter arranged therein, the filter comprises a plurality of section pairs connected in series, each of the plurality of section pairs comprises two sections arranged in the two transmission lines symmetrically, every two adjacent sections are different in line width;
• and
• a ground layer adjacent to and insulated from the signal layer;
• wherein
• a distance between the two transmission lines, and the line width of each of the sections are predetermined according to desired frequency bandwidth and desired frequency response of the differential pair.