本研究以鎳鋅鈷鐵氧體(Ni0.5-0.5xZn0.5-0.5xCox)Fe2O4/Epoxy與羰基鐵/Epoxy製作雙層吸波材料，在背置金屬板的條件下，改善在目標頻率12GHz單層吸波材料吸收頻寬不足的問題。過往本實驗室已探討過不同元素與煆燒溫度之(Ni0.5-0.5xZn0.5-0.5xCox)Fe2O4/Epoxy之吸收效果，但該研究未說明其電磁損耗特性，如attenuation coefficient(α)與Impedance matching ratio(z)，因此在本研究當中，將利用過往量測的複導磁係數與複介電常數重新計算其電磁損耗特性。同時本研究中還將製備並量測2G~18GHz下羰基鐵在Epoxy中不同重量摻雜比之複導磁係數與複介電常數，以計算其電磁損耗特性。然後根據兩材料的電磁損耗特性搭配雙層配置原則，在不同厚度比與總厚度下，數值分析得具有最大吸收頻寬的雙層材料參數組合，最後以該參數組合製作雙層吸波材料並加以量測。
計算結果顯示在(Ni0.5-0.5xZn0.5-0.5xCox)Fe2O4/Epoxy具有較高的z值，且在目標頻率12GHz的條件下以x=0.2、煆燒溫度為1200℃ 具有最大的z值0.49;在α方面為羰基鐵/Epoxy較高，且在目標頻率12GHz下羰基鐵在Epoxy中60 wt%的重量摻雜比例具有最大的α為183.36 Np/m，因此將選用這兩種製程參數進行數值分析。數值分析結果顯示，在中心頻率12GHz下使用雙層配置原則配置方式，即吸收層為attenuation coefficient (α)較大的羰基鐵/Epoxy、匹配層為 Impedance matching ratio(z)較大的鎳鋅鈷鐵氧體/Epoxy在總厚度為7.4mm厚度比(d_1 /d_2)為1.4的條件下具有最大-10dB吸收頻寬5.12GHz。相較於單層羰基鐵/Epoxy在，厚度為2mm具有最大-10dB吸收頻寬4.62GHz，最大反射損耗為-25.1dB。單層在厚度方面明顯優於雙層，而-10dB吸收頻寬為雙層較大，但也僅提升約10%，因此認定此次改善效果不佳。製作與量測結果顯示，雙層羰基鐵/鎳鋅鈷鐵氧體/Epoxy方面，總厚度為7.4mm厚度比為1.4，達-10dB吸收頻寬為3.6GHz，最大吸收峰值為-21.7dB，中心頻率為10.84;單層羰基鐵/Epoxy方面，材料厚度為2mm，達-10dB吸收頻寬為0.72GHz，最大吸收峰值為-20.6dB，中心頻率為11.56，綜合數值分析結果與量測結果，皆顯示了此次改善效果不佳。比對文獻結果，推測原因為材料選擇不佳，所組合為雙層吸波材料的羰基鐵/Epoxy與鎳鋅鈷鐵氧體/Epoxy之α、z差距不夠大。總結以上可得知雙層吸波材料，在材料配置上不僅要符合雙層配置原則，且材料選擇也極為重要，需選用α差距與z差距均較大的兩材料，才具有大的吸收頻寬。

This study is based on the design principles proposed in previous literature. Utilizing a material with a higher Impedance matching ratio (z), specifically (Ni0.4Zn0.4Co0.2)Fe2O4/Epoxy, as the matching layer, and a material characterized by a more significant attenuation coefficient(α), namely carbonyl iron/Epoxy, as the absorption layer, a double-layer absorber material is constructed. Computational analysis indicates that at a central frequency of 12 GHz, a total thickness of 7.4 mm and a thickness ratio of 1.4 yyieldsthe maximum absorption bandwidth. Experimental results under identical conditions reveal a shift in the central frequency to 10.84 GHz, resulting in a reduction of the absorption bandwidth. Both calculations and measurements concur in demonstrating that the double-layer absorber material experiences a slight increase in absorption bandwidth compared to a single-layer counterpart. However, this enhancement comes at the expense of a considerable increase in material thickness. It is deduced that the discourse surrounding the design principles still needs to be completed necessitating the inclusion of materials with a gmoresignificantdisparit in α and z in order to produce absorber materials with an optimally improved bandwidth for absorption.

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