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.

中文翻译：

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变压器耦合磁导率仪对单个磁性粒子的宽带和高灵敏度磁导率测量

摘要 我们开发了一种在宽频率范围内以高灵敏度测量磁导率的系统，我们称之为变压器耦合磁导率计。在该系统中，磁性样品被两个短端接共面波导夹在中间，形成一个松耦合变压器。这样，作为背景的刺激信号随着频率的降低而变小，从而显着抑制了大多数传统渗透计所遭受的低频信噪比（SNR）的恶化。已经证明，该系统可以提供足够高的灵敏度，以测量单个铁磁片状颗粒的磁导率，该颗粒包括 10 MHz–20 GHz 以上的具有高 SNR 的噪声抑制片。