本論文將探討x(Mg0.95Co0.05)TiO3-(1-x)(Ln0.5Na0.5)TiO3微波介電陶瓷的介電特性及材料的微結構(在本論文裡Ln是指鑭系元素中的La+3、Nd+3)。(Ln0.5Na0.5)TiO3陶瓷具有高的介電常數εr和正的共振頻率溫度係數τf。另一方面(Mg0.95Co0.05)TiO3陶瓷具有高品質因素Q×f 和負的共振頻率溫度係數τf。經實驗結果發現，適當調整x值可使τf趨近於零且具有不錯的品質因素Q×f 及介電常數εr。最後，添加燒結促進劑B2O3促使材料緻密化，降低燒結溫度。由實驗結果，添加0.5wt％的B2O3於0.88(Mg0.95Co0.05) TiO3-0.12(La0.5Na0.5)TiO3材料裡，可在1225oC時燒結且具有最佳介電特性；介電常數εr為22.77，品質因素Q×f 為98200，共振頻率溫度係數τf為+1.83ppm/oC。與原來未添加燒結促進劑的材料比較(燒結溫度1325 oC)明顯降低燒結溫度。另外，分別以88MCLNT+ 0.5wt％B2O3此材料及FR4與Al2O3為基板，設計一個使用0°饋入結構的二階Butterworth髮夾式濾波器來比較與驗證此材料88MCLNT+ 0.5wt％B2O3具有穩定的共振頻率溫度係數τf、高介電常數εr及高品質因素Q×f。

The microwave dielectric properties and the microstructures of the x(Mg0.95Co0.05)TiO3-(1-x)(Ln0.5Na0.5)TiO3 ceramics were investigated(where Ln represents a lanthanide: La+3、Nd+3). (Ln0.5Na0.5)TiO3 ceramic has a high dielectric constant εr and a positive temperature coefficient of resonant frequency τf. On the other hand, (Mg0.95Co0.05)TiO3 ceramic has a high quality factor Q×f and a negative temperature coefficient of resonant frequency τf . The results show that zero τf value and excellent Q×f value and dielectric constant εr can be obtained by appropriately adjusting the x value. Finally, we add sintering aid of B2O3 to promote the material density and reduce the sintering temperature. The outcome reveals that the specimen of 0.88(Mg0.95Co0.05)TiO3-0.12(La0.5Na0.5)TiO3 with 0.5wt% B2O3 can be sintered at 1225oC and has the characteristics of εr~22.77、Q×f value~98200、and τf value~+1.83ppm/oC. Compare the material of 88MCLNT+0.5wt％B2O3 with pure material which is sintered at 1325oC, and the sintering temperature of the material of 88MCLNT+0.5wt％B2O3 was Conspicuously reduced. Otherwise, we fabricate a second order Butterworth hairpin filter using 0° feed structure on the substrates 88MCLNT+0.5wt％B2O3, FR4 and Al2O3 respectively to compare and verify that the material of 88MCLNT+0.5％B2O3 has stable temperature coefficient of resonant frequency τf, high dielectric constant εr, and excellent quality factor Q×f.

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