- 學位論文
磁性材料/碳系複合材料電磁波之研究
Study on Electromagnetic Wave Absorption of Magnetic Materials/Carbon Series Composite
摘要
隨著科技日新月異、電子技術的進步，便發明許多便利的電子產品，因此使得電子元件之趨勢亦不斷往高頻化、小型化、數位化發展，更多的電子系統工作在微波頻率範圍內，如行動電話，無線區域網路系統，以及藍牙技術。在這頻率範圍，隨之產生的電磁(EM)波污染問題是個非常嚴重的問題，且也非常迫切需要解決。因此，要求開發更薄，重量更輕電磁波材料的同時也必須兼顧電磁波吸收效果及更廣泛的應用頻率。 本研究是以矽橡膠作為基材，鎳銅鋅鐵氧磁體、鎳鋅鐵氧磁體、錳鋅鐵氧磁體、碳素鐵、碳纖維與碳黑為吸收劑，以高分子混摻法製備具有電磁波功能之複合材料。藉由磁性添加材與導電性添加材之特性，使電磁波能量於材料內部消散。 研究結果顯示，添加量對於鎳銅鋅鐵氧磁體、鎳鋅鐵氧磁體、錳鋅鐵氧磁體、碳素鐵與碳纖維複合材料之電磁波吸收效益均會造成影響，但並無明顯增加。但是材料阻抗有顯著增加。而鎳銅鋅鐵氧磁體、鎳鋅鐵氧磁體、錳鋅鐵氧磁體、碳素鐵與碳纖維、碳黑作為混摻搭配所形成之複合材料，吸收效益顯著增加。又以鎳銅鋅鐵氧磁體(30 vol%)、鎳鋅鐵氧磁體(30 vol%)、錳鋅鐵氧磁體(30 vol%)、碳素鐵(30 vol%)與碳纖維(10 vol%)、碳黑(10 vol%)，於頻率0.9 GHz，有較佳之吸收效益。又以錳鋅鐵氧(30 vol%)/碳纖維(10 vol%)，平均長度41.8 μm，有其最佳吸收效益為-12.3 dB。
並列摘要
Recently, various kinds of devices, which utilize electro-magnetic waves in the range of GHz, have been put intopractical use. Those include cellular telephones, wireless LAN systems, central processing units for computers,satellite-based broadcasting, and so on. In accordance with a rapid and wide spread use of these devices, especiallyfor cellular telephones, electromagnetic interference(EMI) is causing serious problems today. Therefore, the electromagnetic compatible devices can be defined as those that emit no harmful electromagnetic waves outside but protecting its cores from the harmful electromagnetic waves generated from the other devices. In this study, silicone rubber as the substrate, NiCuZn ferrite, NiZn ferrite, MnZn ferrite, carbonyl iron, carbon fiber and carbon black as the absorbent, to polymer blends prepared with electromagnetic waves function of composite materials. By adding magnetic material and conductive characteristics of added material, so that the internal dissipation of electromagnetic energy in the material. The results showed that addition of the NiCuZn ferrite, NiZn ferrite, MnZn ferrite, carbonyl iron and carbon fiber composite materials electromagnetic wave absorption efficiency will be affected, but not significantly increased. However, a significant increase in material resistance. The NiCuZn ferrite, NiZn ferrite, MnZn ferrite, carbonyl iron, carbon fiber and carbon black as a blending with the formation of composite materials, absorption efficiency increased significantly. And NiCuZn ferrite(30 vol%),NiZn ferrite(30 vol%),MnZn ferrite (30 vol%), carbonyl iron(30 vol%) and carbon fiber(10 vol%), carbon black(10 vol%), the frequency of 0.9 GHz, have higher absorption efficiency.MnZn Ferrite(30 vol%)/carbon fiber(10 vol%), average length of 41.8 μm, has the best absorption efficiency as -12.3 dB.