MgTiO3介電陶瓷微波特性探討與DGS濾波器之研製

Investigation for Microwave Properties of MgTiO3 Dielectric Ceramics and Research of the DGS Filters

譚祖崇(Tsu-Chung Tan)

指導教授 ： 孫迺翔

共同指導教授 ： 潘宗龍(Chung-Long Pan)

義守大學/電機資訊學院/電機工程學系/博士(2014年)

https://doi.org/10.6343/ISU.2014.00320

摘要

本論文共分兩大研究主題，第一部分研究陶瓷材料之微波介電特性，其高介電常數與低損耗與穩定的共振頻率溫度係數的微波材料(1-x)MgTiO3-x(Ca0.8Sr0.2)TiO3之陶瓷基板，非常適合作為微波元件之應用，使得被動元件的尺寸有效縮小。
論文第二部份為濾波器的探討研究，傳統的SIR(Stepped Impedance Resonators)濾波器的電路佈局偏狹長型，對電路的整合有一定的難度;因此，利用分支饋入(Tap In)的方法，降低插入損耗(Insertion Loss)以及減少一階的共振結構；並使用過耦合方式增加耦合量進而減少了濾波器體積，最後靠著適當地控制饋入點的位置，即可在所需求的頻段產生零點，我們可以量測到通帶的兩旁衰減量增加，使整個濾波器的選擇性提高。最後針對圓形接地缺陷結構(Circle-defected ground structures, C-DGS)的各項參數:半徑、間距、個數等，以完成其新型等效電路之推導。然後將C-DGS整合至SIR濾波器，以改善在f2=5.25GHz的頻率響應。從模擬與實作測量中可以證實加入C-DGS能夠有效改善f1=2.45GHz、f2=5.25GHz的通帶響應並抑制諧波。

關鍵字

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並列摘要

This work is divided into two research focuses. In our first part, we research the microwave properties of dielectric ceramic materials, specifically using the ceramic substrate (1-x)MgTiO3-x(Ca0.8Sr0.2)TiO3, which has a high dielectric constant, low loss, and a stable resonant frequency temperature coefficient. We propose that this ceramic material effectively reduces component size, and is an ideal candidate for applications as a passive component.
The second part of this dissertation emphasizes our research on wave filters. The traditional Stepped Impedance Resonator (SIR) has a lengthy and narrow design, and presents a degree of difficulty for circuit integration. Thus, by using tap in method, we reduce the insertion loss and further reduce a section of resonators. Using over coupling method, we increase the coupler coupling and reduce the size of the filter. By controlling the tap-point location, we produce a transmission zero in the necessary frequency, and through testing the attenuation in the regions adjacent to the passband, we improve the selectivity of the wave filter.
In the final part of our work, from various parameters of the Circle-Defected Ground Structure (C-DGS) such as radius, spacing, quantity etc., we derive its new equivalent circuit. Integrating the C-DGS into SIR, we improve its frequency response at f2=5.25GHz. Through simulations and experimental, we prove that the C-DGS can effectively improve the pass band response and suppress harmonic at f1=2.45GHz、f2=5.25GHz.

並列關鍵字

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參考文獻

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[2] Chung-Long Pan, Chun-Hsu Shen, Ping-Cheng Chen, Tsu-Chung Tan, ” Characterization and dielectric behavior of a new dielectric ceramics MgTiO3–Ca0.8Sr0.2TiO3 at microwave frequencies”, ELSEVIER Journal of Alloys and Compounds 503 (2010) 365–369.

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