内置负载开缝腔体谐振效应抑制方法研究

开缝腔体谐振特性放大了进入腔内的耦合能量,对内部电子设备构成严重威胁。文中建立内含金属 隔板、吸波体等负载的圆柱腔体模型,提出了在隔板上涂覆吸波材料以抑制谐振的新方式,研究了吸波体电磁特性 对谐振的影响。结果表明:隔板越靠近腔体前壁放置、板间距越大,对内部场影响越小,谐振点出现位置越接近空腔 固有模式;谐振点处屏蔽效能(Shielding Efficiency, SE)的提升是隔板和吸波材料综合作用的结果,隔板可迫使谐振 点迁移,吸波材料能改善谐振特性,并且涂覆磁性吸波材料性能更优;在隔板双面涂敷吸波材料抑制高次谐振效果 更好;适当增加隔板上涂覆材料厚度或提高材料相对磁导率,都能实现和全腔内壁涂覆相同的谐振抑制效果,效费 比也更高;场强分布因传播模式不同而不同,强电场区应放置电性吸波体才有效。

Study on the Inhibition Method of Resonance Effect for the Slotted Cavity with Load

The resonant of slotted cavity amplifies the coupling energy entering the cavity, which poses a serious threat to the electronic equipment. The model of cylindrical cavity with metal plate and absorber is established. A new method of coating absorbing material on the plate is proposed, and the influence of the electromagnetic characteristics is studied. The results show that: Closer to the front wall and the larger the spacing, the smaller the influence on the field, and closer the resonance point to the cavity mode. The SE improvement at the resonance point is the comprehensive result of the plate and the absorbing material. The plate can force the resonance point to move. The absorbing material can improve the resonance, and the performance of the coated magnetic absorbing material is better. Coating absorbing material on both sides of plate can restrain high order resonance effectively. Increasing the plate thickness or the material relative permittivity can achieve the same suppression effect as the coating on the whole cavity. The field intensity distribution varies with different propagation modes, and the electric absorber should be placed in the strong electric field area to be effective.