a transmission line includes a high permeability conductor . the high permeability conductor increases the inductance - per - length of the transmission line to reduce the propagation velocity along the line . the high permeability conductor supplements a high dielectric constant insulator and high permeability core that increase the capacitance - per - length and inductance - per - length , respectively . in one embodiment , the transmission line is a microstrip line that is used in a matrix addressable display . in another embodiment , the transmission line is a coaxial line where the central conductor includes a center layer of nonmagnetic material and an outer layer of high permeability material . the high permeability conductor can be formed from a single layer of high permeability material or may be formed from a central layer of high conductivity material coated with an outer layer of a high permeability conductor .