A microstrip transmission line consists of a narrow metallic trace separated from a metallic ground plane by a slab of dielectric material. This is a natural way to implement a transmission line on a ...A microstrip transmission line consists of a narrow metallic trace separated from a metallic ground plane by a slab of dielectric material. This is a natural way to implement a transmission line on a printed circuit board, and so accounts for an important and expansive range of applications. The reader should be aware that microstrip is distinct from stripline, which is a very different type of transmission line.