Electromagnetic bandgap structure and printed circuit board

Abstract

An electromagnetic bandgap structure and a printed circuit board that have a mushroom type structure. The electromagnetic bandgap structure includes a first metal layer; a first dielectric layer, layer-built on the first metal layer; a mushroom type structure having a metal plate layer-built on the first dielectric layer and a via of which one end is connected to the metal plate; a second dielectric layer, layer-built on the metal plate and the first dielectric layer; and a second metal layer, layer-built on the second dielectric layer, wherein the other end of the via is placed in a hole formed on the first metal layer and is connected to the first metal layer through a metal line.

1 . An electromagnetic bandgap structure, comprising:
 a first metal layer;   a first dielectric layer, layer-built on the first metal layer;   a mushroom type structure comprising a metal plate layer-built on the first dielectric layer and a via of which one end is connected to the metal plate;   a second dielectric layer, layer-built on the metal plate and the first dielectric layer; and   a second metal layer, layer-built on the second dielectric layer,   wherein the other end of the via is placed in a hole formed on the first metal layer and is connected to the first metal layer through a metal line.   
     
     
         2 . The electromagnetic bandgap structure of  claim 1 , wherein the other end of the via is connected to a via land placed in the hole and the metal line connects the via land and the first metal layer. 
     
     
         3 . The electromagnetic bandgap structure of  claim 1 , wherein the hole accommodates the via and the metal line. 
     
     
         4 . The electromagnetic bandgap structure of  claim 1 , wherein there are a plurality of mushroom type structures between the first metal layer and the second metal layer. 
     
     
         5 . The electromagnetic bandgap structure of  claim 1 , wherein the metal line has a spiral structure that is wound around the other end of the via. 
     
     
         6 . The electromagnetic bandgap structure of  claim 1 , wherein an electromagnetic wave of a certain frequency range is prevented from being transferred, by using an inductance that is serially connected between the metal plate and the first metal layer corresponding to the via. 
     
     
         7 . A printed circuit board having an analog circuit and a digital circuit, comprising:
 a first metal layer;   a first dielectric layer, layer-built on the first metal layer;   a mushroom type structure comprising a metal plate layer-built on the first dielectric layer and a via of which one end is connected to the metal plate;   a second dielectric layer, layer-built on the metal plate and the first dielectric layer; and   a second metal layer, layer-built on the second dielectric layer,   wherein an electromagnetic bandgap structure is placed between the analog circuit and the digital circuit, and the other end of the via is placed in a hole formed on the first metal layer and is connected to the first metal layer through a metal line.   
     
     
         8 . The printed circuit board of  claim 7 , wherein the first metal layer is one from the group consisting of a ground layer and a power layer, and the second metal layer is the other from the group consisting of the ground layer and the power layer. 
     
     
         9 . The printed circuit board of  claim 7 , wherein the analog circuit is an RF circuit comprising an antenna receiving an RF signal from the outside. 
     
     
         10 . The printed circuit board of  claim 7 , wherein the other end of the via is connected a via land placed in the hole and the metal line connects the via land and the first metal layer. 
     
     
         11 . The printed circuit board of  claim 7 , wherein the hole accommodates the via and the metal line. 
     
     
         12 . The printed circuit board of  claim 7 , wherein there are a plurality of mushroom type structures between the first metal layer and the second metal layer. 
     
     
         13 . The printed circuit board of  claim 1 , wherein the metal line has a spiral structure that is wound around the other end of the via. 
     
     
         14 . The printed circuit board of  claim 1 , wherein an electromagnetic wave of a certain frequency range is prevented from being transferred, by using an inductance that is connected between the metal plate and the first metal layer corresponding to the via.