The array of lines is held stationary on the surface of a substrate comprising a low loss polymer film (such as Kapton), glass, ceramic, Al2 O3, or other dielectric material with a low loss tangent, i.e. whose conductivity remains below about 10-7 ohm-1 cm-1 over the range of use (which may be from 0???-400??? C.)--that is, over a frequency range of one Hz to about 10 megahertz.