铁氧体/羰基铁粉复合吸波材料研究

采用化学共沉淀法制备了W型六角晶系钡铁氧体,测试其在掺杂不同含量羰基铁粉后的电磁参数,利用传输线理论对电磁参数进行计算模拟,得到了2～18 GHz下该材料的平板反射率曲线,研究了羰基铁粉掺杂对铁氧体电磁特性的影响。结果表明:随羰基铁粉含量的增加,复合吸收剂在匹配厚度逐渐减小时,吸波效能逐渐增加。当铁氧体与羰基铁粉的质量比为10∶.3,样品的匹配厚度为2.4 mm时,涂层在该厚度下的理论吸收峰值为-61.88 dB,吸收率小于-10 dB的带宽达到7.48 GHz;涂层厚度为2 mm时的微波衰减能力仍能满足使用要求。掺杂后铁氧体的复数磁导率的频散效应的减弱是吸波性能显著改善的主要原因。

Study on ferrite/carbonyl iron composite absorber

W-type hexagonal ferrite were prepared by chemical coprecipitation method and then mixed with different content of carbonyl iron(CI).The electromagnetic parameters of the compounds were measured using a microwave vector network analyzer and the reflection coefficient of one-layer absorber was numerically calculated.Also,the complex permeability and complex permittivity of compounds were studied.The results show that smaller matching thickness and better microwave absorption were obtained when increasing the content of CI.The matching thickness of the compound with ferrite/CI weight ratio of 1∶0.3 decreases to 2.4 mm,while the maximal theoretical absorption reaches-61.88 dB and the bandwidth(with respect to-10 dB absorption) is 7.48 GHz at the matching thickness.Especially,the ferrite/CI absorber still has high absorption at the thickness of 2 mm.The weakening of dispersion effect of ferrite by mixing with CI results in the absorption improvement.