Effects of the magnetic layer length on the high-frequency characteristics of an integrated-type coplanar wave-guide transmission line

Abstract Integrated-type electromagnetic noise suppressors, based on a coplanar wave-guide transmission line, are investigated, incorporated with a SiO 2 dielectric and a nanogranular Co–Fe–Al–O magnetic thin film. The length of the magnetic thin film is varied from 2 to 15 mm, while its thickness and width are fixed at 1 and 50 μm, respectively. In the measurement frequency range of 0.1–20 GHz, no obvious resonance is seen at the shortest length of the magnetic thin film, but resonance behavior occurs at larger length. A very clear resonance occurs at the largest length of 15 mm, where the resonance frequency is ∼10 GHz and the signal attenuation is as large as −20 dB. The observed resonance frequency is much higher than the ferromagnetic resonance frequency and the main mechanism of loss generation is found to be L – C resonance.