Multilayer board and electronic device

An electronic device comprising:

• a first circuit;
• a second circuit;
• and
• a multilayer board;
• wherein
• the first circuit and the second circuit are connected by the multilayer board;
• the multilayer board includes:
• a layered body including a plurality of insulating base material layers that are layered;
• and
• a first signal line, a second signal line, a first ground conductor including a first opening, a second ground conductor, a third ground conductor, an interlayer connecting conductor, and a first sub-ground conductor provided in and on the plurality of insulating base material layers;
• wherein
• a first transmission line includes the first signal line, the first ground conductor, the second ground conductor, the insulating base material layer sandwiched between the first signal line and the first ground conductor of the plurality of insulating base material layers, and the insulating base material layer sandwiched between the first signal line and the second ground conductor of the plurality of insulating base material layers;
• a second transmission line includes the second signal line, the second ground conductor, the third ground conductor, the insulating base material layer sandwiched between the second signal line and the second ground conductor of the plurality of insulating base material layers, and the insulating base material layer sandwiched between the second signal line and the third ground conductor of the plurality of insulating base material layers;
• the first signal line overlaps the first opening when seen in a layering direction of the plurality of insulating base material layers;
• no signal line exists between the second signal line and the first signal line;
• the second signal line is provided on a layer different from a layer of the plurality of insulating base material layers including the first signal line;
• the second signal line includes a portion extending side by side with the first signal line when seen in the layering direction;
• the first ground conductor, the second ground conductor, and the third ground conductor are connected by the interlayer connecting conductor;
• the third ground conductor is disposed on a layer of the plurality of insulating base material layers including the first signal line or a layer of the plurality of insulating base material layers positioned between the first signal line and the second signal line of the plurality of insulating base material layers;
• the first sub-ground conductor is disposed between the first signal line and the second signal line when seen in the layering direction and disposed between the second ground conductor and the third ground conductor in the layering direction;
• and
• the second ground conductor and the third ground conductor are connected by the first sub-ground conductor and the interlayer connecting conductor.