1. A coupled via structure comprising:a plate via penetrating through a board body, the plate via including a first plate and a second plate, the first plate and the second plate facing each other with a first gap distance therebetween;
a contact pad connected to the plate via on a surface of the board body, the contact pad including a first contact connected to the first plate and a second contact connected to the second plate, the first contact and the second contact being separated from each other; and
a connection line connected to the contact pad on the surface of the board body, the connection line including a first line and a second line, the first line connected to the first contact and the second line connected to the second contact, the second line being spaced apart from the first line by a second gap distance such that the connection line is connected to a coupled signal line having a main signal line for transferring a main signal and a complementary signal line for transferring a complementary signal with respect to the main signal,
wherein the contact pad is in a shape of a plate having a width and a thickness such that the width of the contact pad substantially equals a width of the plate via and a thickness of the contact pad substantially equals a thickness of the plate via.