High Frequency Micro-Patterned Fe65Co35 Thin Film with Tunable FMR and Permeability for RF Passives

This paper presents a unique design method and optimization of high frequency magnetic patterns with controllable effective permeability and ferromagnetic resonance behavior for integrated microwave devices. Thin-film micro-patterned FeCo array with initial permeability of 42.7 has been fabricated to achieve a high ferromagnetic resonance (FMR) frequency of 18.1 GHz. Control of magnetic properties of the pattern array has been realized by changing pattern spacing, showing a FMR tuning range of 2.20 GHz, with little change in effective permeability. Noise suppression and inductance enhancement at high frequencies (> 10 GHz) have been demonstrated for RF applications by integrating magnetic pattern arrays with coplanar waveguides (CPW). Our method shows a high degree of freedom and flexibility for designing high frequency integrated magnetic microwave components.