Wide bandwidth pyramidal absorbers of granular ferrite and carbonyl iron powders
Wide bandwidth pyramidal absorbers of granular ferrite and carbonyl iron powders
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DOI：
10.1109/20.908766
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发表时间：
2000-09-01
影响因子：
2.1
通讯作者：
Kim, SS
中科院分区：
文献类型：
--
作者：
Park, MJ;Choi, JH;Kim, SS
采用宽损耗谱的磁性材料，设计了适用于小型或半消声室的宽频带（GHz）金字塔形吸波体。采用传输线近似方法分析了锥形吸波体的微波吸收特性，给出了反射损耗与材料参数和吸波体高度的关系。结果表明，磁损耗谱是实现宽带化的最关键参数。为了获得宽带化的磁损耗谱，在硅橡胶粘结剂中按适当的比例加入了两种磁性填料。一种是具有低频磁共振的Ni-Zn铁氧体，另一种是具有高频弛豫损耗的羰基铁。在这些复合材料中具有受控的锥形几何形状，预测了很宽的带宽（1-18 GHz，相对于-20 dB的反射损耗）。
Pyramidal absorbers with wide bandwidth in the GHz region are designed with magnetic materials of broad loss spectrum for application to small or semi-anechoic chambers. Microwave absorbing properties of pyramidal cone absorber are analyzed by the transmission line approximation which provides the reflection loss as a function of material parameters and absorber height. It has been found that the magnetic loss spectrum is the most critical parameter to realize wide bandwidth, For the attainment of a broad loss spectrum, two kinds of magnetic fillers are used in appropriate proportions in silicon rubber binder. One is Ni-Zn ferrite with magnetic resonance at low frequency and the other is carbonyl iron with high-frequency relaxation loss, With a controlled geometry of pyramidal cone in those composites, a very wide bandwidth (1-18 GHz with respect to -20 dB reflection loss) has been predicted.