High Frequency Permeability of CoNbZr Thin Films Prepared by Tetrode Sputtering Method

A new strip-line method for measuring the permeability of CoNbZr thin films at high frequencies (1 ~ 400 MHz) is discussed. Low-frequency measurements (less than 1 MHz) are possible using a coil, but this is impossible at higher frequencies because of the resonance between the coil windings. The strip-line method employs a section of the film sample (in this case 13 mm × 55 mm × 1 ¿m), a glass epoxy spacer, a glass substrate and a 4191A measuring instrument. Smaller samples (13 × 13 mm) were also tested, but greater film volumes provided better accuracy.