Electromagnetic bandgap structure and printed circuit board

A printed circuit board having an analog circuit and a digital circuit, the printed circuit board in which an electromagnetic bandgap structure is disposed between the analog circuit and the digital circuit, the electromagnetic bandgap structure comprising:

• a first metal plate, formed between the first dielectric layer and the second dielectric layer;
• a second metal plate, formed on a same planar surface as the first metal plate, accommodated into a hole which is formed in the first metal plate and electrically connected to the first metal plate through a metal line;
• and
• a via, connecting the second metal plate to any one of the first metal layer and the second metal layer.

An electromagnetic bandgap structure, comprising:

• a first metal layer;
• a first dielectric layer, stacked in the first metal layer;
• a metal plate, stacked in the first dielectric layer;
• a via, having one end part which is connected to the first metal layer;
• a second dielectric layer, stacked in the metal plate and the first dielectric layer;
• and
• a second metal layer, stacked in the second dielectric layer,
• whereas the other end part of the via is connected to a via land which is placed in a hole formed in the metal plate, and the via land is connected to the metal plate through a metal line.

A printed circuit board having an analog circuit and a digital circuit, the printed circuit board in which an electromagnetic bandgap structure is disposed between the analog circuit and the digital circuit, the electromagnetic bandgap structure comprising:

• a first metal layer;
• a first dielectric layer, stacked in the first metal layer;
• a metal plate, stacked in the first dielectric layer;
• a via, having one end part which is connected to the first metal layer;
• a second dielectric layer, stacked in the metal plate and the first dielectric layer;
• and
• a second metal layer, stacked in the second dielectric layer,
• whereas the other end part of the via is connected to a via land which is placed in a hole formed in the metal plate, and the via land is connected to the metal plate through a metal line.