活性碳毡电路屏(直立碳纤维)/树脂复合吸波材料

Microwave absorbing properties of active carbon-fiber felt screens (vertical-arranged carbon fibers)/epoxy resin composites

研究了含活性碳毡电路屏和直立碳纤维吸波复合材料的微波吸收特性。结果表明：含碳毡电路屏吸波材料的吸波性能与电路屏的种类（感性、容性）和尺寸密切相关。含感性屏的吸波材料，当毡条间距、宽度分别为7mm、5mm时，材料在整个雷达波段（8～18GHz）有-10dB以下的反射衰减。含容性屏的吸波材料，随电路屏中碳毡块间距和边长的减小，吸波性能提高。含直立碳纤维材料的吸波性能与纤维间距有关，间距为4mm时可获得有效带宽7．6GHz的吸波材料。用分块设计的思想设计吸波材料，可提高其吸波性能。分块中心对称的感性电路屏（毡条宽5mm，间距10mm）和直立碳纤维（间距8mm）混杂吸波体在11．8～18GHz频带内有低于-20dB的反射衰减，最大吸收峰值-30dB。

Microwave absorbing properties of the composites containing active carbon-fiber felt screens （ACFFSs） or vertical-arranged carbon fibers （VACFs） were investigated respectively. The results show that the absorbing performances of the composites containing ACFFSs are affected greatly by the patterns （inductive or capacitive） and the element configurations of ACFFSs. The composite containing the inductive screen obtains a reflection loss below --10 dB at 8-18 GHz, which is the frequency region of the radar, when the distance between strips and the width of strips are 7 mm and 5 mm respectively. The absorption effect of the composites rises with reducing the side of plates or the distance between plates in the capacitive screen. The space between fibers is critical for the absorbing performances of the composites containing VACFs. The bandwidth below --10 dB is 7.6 GHz when the space is 4 mm. By applying the block design method, the composite was divided into four sub-regions which were centrosymmetrical and contained two inductive screens and two VACF regions. The composite achieves a reflection loss below --20 dB at 11.8-18 GHz and the minimum value reaches --30 dB when the distance between strips, the width of strips and the space between fibers are 10 mm, 5 mm and 8 mm separately.