A printed circuit board includes a first signal layer, a first reference layer, a second reference layer, and a second signal layer. An integrated circuit mounted on the first signal layer includes a power supply terminal connected to a first power supply via. The second signal layer includes a filter and a power supply wire. The filter includes a power terminal connected to the first power supply via, and a ground terminal connected to the second reference layer. The first power supply via is connected to the first reference layer through the power supply wire and a second power supply via. A void defined in the second reference layer is at least partially vertically overlapping with the power supply wire, and enables the first reference layer to function as a reference plane for the power supply wire, to increase impedance of the power supply wire.