Microwave transmission and reflection properties of Permalloy thin films
Havemann, Robert Harvey
Davis, L. E.
Master of Science
Theoretical expressions are derived for the transmission and reflection coefficients of an electromegnetic wave normally incident on an unmagnetized, magnetic, conducting thin film and glass substrate positioned transversely in rectangular waveguide. Sondheimer's theoretical conductivity is calculated and compared with measured dc film conductivity, and the sensitivity of Sondheimer's conductivity to variations in mean free path is examined. Theoretical expressions for transmission and reflection coefficient are evaluated in terms of both theoretical and experimental conductivity, theoretical permeability, measured film thickness, measured substrate dielectric constant, and frequency of experimental operation. Theoretical transmission and reflection coefficients are then graphically compared with experimental measurements of transmission and reflection coefficients at a frequency of 10 GHz. Experimental and theoretical results agree within the limits of experimental accuracy.