Skin Effect and Its Effect on PCB Impedance
Simply put, the Skin Effect is the significant factor that cause the signal loss. At low frequencies, the current density inside the conductor is uniform, and the current flowing in the center is the same as the current density at the edges. But when the frequency gradually increases, the flowing charges will gradually approach the edge, and even no current will pass through the middle.
What is the specific impact of the skin effect in the actual PCB routing? For short transmission circuits, the loss in transmission can ideally be ignored. However, in practical, especially circuits with long-distance transmission, the additional loss caused by the existence of transmission trace resistance should be significantly considered. Thus, for PCBs, especially with high speed and high frequency features, when design and adjust the trace width to meet the impedance value, should consider the Skin effect and avoid the EMC issues.
What is the specific impact of the skin effect in the actual PCB routing? For short transmission circuits, the loss in transmission can ideally be ignored. However, in practical, especially circuits with long-distance transmission, the additional loss caused by the existence of transmission trace resistance should be significantly considered. Thus, for PCBs, especially with high speed and high frequency features, when design and adjust the trace width to meet the impedance value, should consider the Skin effect and avoid the EMC issues.