薄膜铁磁材料特征参数扫场/扫频测试方法探讨

Study on Field/Frequency Sweep Measurement for Parameters of Thin Film Ferromagnetic Materials

微波薄膜铁磁材料主要参数是共振磁场强度和共振线宽,基于VNA的扫场测试可直接得到共振磁场强度和共振线宽,而且测量精度高,可测量薄膜方向性,但耗时长。而扫频测试虽然只能得到谐振点频率和频率宽度,且精度低,但速度极快。通过理论论证和实验分析,探讨了一种扫场和扫频相结合的新技术来解决这个矛盾。首先估算铁磁材料的另两个特征参数旋磁比γ和饱和磁化强度Ms,然后由扫频频宽来估算共振线宽。实验表明,扫频估算线宽与扫场测量线宽的差异在6%以下。

The main parameters of microwave thin film ferromagnetic materials are the resonance magnetic field intensity and linewidth.They can be directly obtained by field-scanning test based on VNA with high accuracy,and the directivity can be measured,but measurement time is very long.Although the frequencyscanning test can get the resonant frequency and frequency width,and the accuracy is low,but the speed is extremely fast.Based on theoretical analysis and experimental verification,this paper discusses a new technique combining field-scanning and frequency-scanning to solve this contradiction.Firstly,two characteristic parameters,the gyromagnetic ratioγand the saturation magnetization intensity Ms,were estimated.Then the resonance linewidth is estimated from frequency width.The tests show that the difference is less than 6%.