Circuit board and electronic device

A circuit board, comprising:

• a signal layer, wherein the signal layer comprises at least one set of differential wires, and the at least one set of differential wires comprises a first differential wire and a second differential wire that are insulated from each other, the first differential wire comprises a first part, a second part, and a third part that are arranged successively in an extension direction of the first differential wire;
• and the second differential wire comprises a fourth part, a fifth part, and a sixth part that are arranged successively in an extension direction of the second differential wire;
• and
• a ground plane, wherein the ground plane is disposed on at least one side of the signal layer, and is insulated from the signal layer;
• and the ground plane is provided with a first hollowed-out portion, and an orthographic projection of the first hollowed-out portion on the signal layer overlaps with the second part and the fifth part, wherein the ground plane is enclosed by the first hollowed-out portion into a first branch and a second branch, the first branch and the second branch are respectively disposed on opposite sides of the first hollowed-out portion, and the first branch and the second branch comprise protrusions that protrude in a vertical direction between the first differential wire and the second differential wire.