Broadband and high-sensitivity permeability measurements on a single magnetic particle by transformer coupled permeameter
Abstract
We have developed a system to measure permeability over a wide frequency range with high sensitivity, which we call the transformer coupled permeameter. In this system, the magnetic sample is sandwiched by two short-terminated coplanar waveguides that form a loosely coupled transformer. In this way, the stimulus signal acting as a background becomes smaller as the frequency decreases, thus significantly suppressing the deterioration of the signal-to-noise ratio (SNR) at low frequencies that most conventional permeameters suffer from. It has been demonstrated that this system can provide a sensitivity high enough to measure the permeability of a single ferromagnetic flake particle comprising a noise suppression sheet over 10 MHz-20 GHz with a high SNR.
- Publication:
-
Journal of Magnetism and Magnetic Materials
- Pub Date:
- May 2020
- DOI:
- 10.1016/j.jmmm.2020.166434
- Bibcode:
- 2020JMMM..50166434T
- Keywords:
-
- Complex permeability;
- Ferromagnetic resonance;
- Magnetic powder;
- Magnetization dynamics