Printed circuit board, backplane architecture system, and communication device

A communication device, comprising:

• a cabinet;
• and
• a printed circuit board inserted into the cabinet and comprising:
• a plurality of layer structures disposed in a stacked manner and comprising ground layers and conductor layers that are alternately arranged, wherein an outermost layer structure of the layer structures comprises a disposing face;
• a differential pair unit disposed on the disposing face and comprising:
• signal via holes, wherein each of the signal via holes passes through at least some of the ground layers and the conductor layers, and is connected to a first trace at a first conductor layer of the conductor layers;
• and
• anti-pads respectively corresponding to the signal via holes, disposed on a first ground layer through which the signal via holes pass, and arranged at intervals;
• and
• a shielding structure configured to shield the differential pair unit, disposed on the disposing face, and comprising:
• primary ground holes located on sides of the differential pair unit;
• and
• a first secondary ground hole disposed on the disposing face and located between the signal via holes,
• wherein the primary ground holes and the first secondary ground hole separately pass through at least some of the conductor layers and the ground layers,
• wherein the primary ground holes and the first secondary ground hole are separately grounded to a second ground layer through which the primary ground holes and the first secondary ground hole pass,
• wherein the primary ground holes and the first secondary ground hole are arranged in a vertical direction to form a ground hole array, and
• wherein the ground hole array and the anti-pads are combined to form a small-sized grid in three-dimensional space in a package region of the printed circuit board.