| The use of ferromagnetic metals in microwave device applications has been studied by only a few research groups and only during the past fifteen or so years. This is surprising, however, because ferromagnetic metals possess several properties that are desirable for these applications. These properties include high saturation magnetization, which allows high operating frequencies, ease of fabrication, which allows monolithic integration with solid-state devices, and other properties.; Previous experimental studies of ferromagnetic conductor applications have primarily focused on tunable band-stop filter effects in microstrip transmission lines. This study seeks to improve on these effects in this geometry, but also includes two additional effects and one additional geometry. A tunable phase-shift effect near ferromagnetic resonance and a tunable band-pass effect at ferromagnetic anti-resonance are presented. Band-stop and phase-shift effects in coplanar waveguide transmission lines, which hold several advantages over microstrip lines, are also presented.; Very few theoretical models of ferromagnetic metal-based devices have been reported by researchers over the past fifteen years and among those reports only two, by Robert Camley and his co-workers, have investigated the phase-shift and band-pass effects. In contrast with Dr. Camley's work, which was based on first-principles and was limited to the microstrip geometry, a model based on the phenomenon of surface impedance, which is a valid approximation for a variety of geometries and which is easier to calculate, is described. This model is used to derive the limits of operation for various devices and effects and the results of this model are compared with experimental results. |
