Transmission line assembly, printed circuit board assembly, and electronic device

A transmission line assembly, configured to be connected to a printed circuit board, wherein a signal end and a ground end are disposed on a surface of the printed circuit board, and the transmission line assembly comprises:

• a shielding cover, wherein the shielding cover is configured to be connected to the ground end, the shielding cover has an accommodation space, and a first opening and a second opening are provided in the accommodation space;
• and
• a signal line, wherein the signal line comprises a first end and a second end that are disposed opposite to each other, the signal line penetrates the accommodation space, there is a gap between the signal line and an inner side wall of the accommodation space, the first end passes through the first opening, the second end passes through the second opening, and at least one of the first end and the second end is configured to be connected to the signal end.