本文以Mg2TiO4為主體，探討Mg2TiO4、Mg2(Ti0.95Sn0.05)O4和(Mg0.95Zn0.05)2TiO4 三種介電材料之共振頻率溫度漂移係數改善方法。為了將其負的共振頻率溫度飄移係數調整至趨近於零，我們添加具正值共振頻率溫度飄移係數的鈣鈦礦材料Ca0.8Sr0.2TiO3(+991 ppm/°C)及Ca0.8Sm0.4/3TiO3(+400 ppm/°C)。經由實驗的結果，我們得知0.85(Mg0.95Zn0.05)2TiO4–0.15Ca0.8Sm0.4/3TiO3有最佳的微波介電特性，其 約為19.92、Q×f約為127,000 GHz (at 9.5 GHz)及τf約為–0.8 ppm/°C。
接下來，我們設計和實作一操作在2.4 GHz的帶通濾波器，濾波器主要由兩個U型諧振器經由電場耦合的方式來組成，並利用零度饋入線在其通帶的左右兩側各產生一零點，最後再加入一開路殘段來抑制其倍頻響應。我們將設計好的電路實作在FR4、氧化鋁和0.85(Mg0.95Zn0.05)2TiO4–0.15Ca0.8Sm0.4/3TiO3基板上，並量測其各自的頻率響應，經由量測的結果得知，印刷在0.85(Mg0.95Zn0.05)2TiO4–0.15Ca0.8Sm0.4/3TiO3基板上的濾波器擁有最低的插入損耗以及最小的原件尺寸，由此可說明利用高介電係數及高品質因數的材料確實能達到降低損耗和縮小面積的需求。

The improvement of τf of Mg2TiO4, Mg2(Ti0.95Sn0.05)O4 and (Mg0.95Zn0.05)2TiO4 base on Mg2TiO4 structure have been investigated. In order to adjust their negative τf, Ca0.8Sr0.2TiO3 and Ca0.8Sm0.4/3TiO3 perovskite which have positive τf had been add. The experiment result showed that 0.85(Mg0.95Zn0.05)2TiO4–0.15Ca0.8Sm0.4/3TiO3 have the best microwave dielectric properties, it’s ~ 19.92, Q×f ~ 127,000 GHz (measured at 9.5 GHz) and τf ~ –0.8 ppm/°C.
Then, we design and fabricate a microwave band-pass patch filter which resonant at 2.4 GHz. The filter was constructed by two U shape resonators using electric coupling. To product two transmission zeros upper and lower the resonant frequency, zero-degree feed tapping feed lines were be used. Finally, an open-stub was added to suppress the spurious response. The pattern was printed on FR4, Al2O3 and 0.85(Mg0.95Zn0.05)2TiO4–0.15Ca0.8Sm0.4/3TiO3 substrates. By measured their frequency responses, filer fabricated on 0.85(Mg0.95Zn0.05)2TiO4–0.15Ca0.8Sm0.4/3TiO3 substrate have the lowest insertion loss and the minimum size, which point out that dielectric material with high dielectric constant and high quality factor can improve the loss and reduce filter’s size.

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