PCB Return-Current Distribution in a Microstrip Line
This article discusses the distribution of a PCB return current underneath top trace for the microstrip configuration. Next month’s article will discuss the distribution for the stripline configurations.
It is well known (but often forgotten) that the concept of inductance, without defining a complete loop of current, is completely meaningless! Some books give inductance of a length or wire, some people talk about the inductance of a via, and still others talk about the inductance of ground braids, etc. All these discussions about inductance ignore the requirement for a complete loop before the total or loop inductance can be discussed in any meaningful way.
