蕈狀結構結合懸置微帶線的多頻EBG特性

Abstract

蕈狀結構是一種後設材料，因為它擁有很多獨特的電磁特性，所以近年來被廣泛的應用在微波電路和天線通訊上面。而本論文著重的是，蕈狀結構結合懸置微帶線架構的電磁帶隙特性。而傳統的蕈狀結構的應用，多半只有操作在單一頻率的電磁帶隙特性，而本論文就針對了蕈狀結構結合懸置微帶線架構的電磁帶隙特性研究，並提出了一種新的穿插週期排列的概念，透過電路模擬與實作量測的驗證，我們成功的讓蕈狀結構結合懸置微帶線的架構展現出多頻電磁帶隙的特性，並且，我們利用了這一個新概念設計了一種新型的微波電路。而這個新型的微波電路，我們稱為三頻雙工器。這支三頻雙工器，它結合了三工器和雙工器的功能，透過這支三頻雙工器的完成，我們能讓GSM 1800MHz、WiFi 2.45GHz和WiMAX 3.5GHz，這三種不同頻段的系統，作多頻段與多通道的整合，進而擁有三個系統相互之間的資料傳輸功能，我們相信這可以提升現今的無線通訊產業對於整合型通訊系統技術的發展，也確信這可以為未來通訊科技的進步帶來貢獻。

Mushroom structure, which is one kind of the meta-materials, exhibits unique electromagnetic properties that have led to a wide range of application in microwave and antenna community. This thesis is devoted in the electromagnetic band-gap (EBG) characteristic of the mushroom structure with the suspending microstrip line. But, most of the traditional mushroom structures are restricted to only single EBG frequency design. In this thesis, we propose a novel concept about the interlaced periodic arrayal of the mushroom structure with the suspending microstrip line. By the simulation and measurement result, it is verified that the mushroom structure with the suspending microstrip line can reveal multi-band EBG characteristic. Moreover, we use the new concept to design a novel microwave circuit called Tri-duplexer, which composites both the capability of the Triplexer and the duplexer. The Tri-duplexer can integrate with the systems, which have operating frequency at GSM 1800MHz, WiFi 2.45GHz, and WiMAX 3.5GHz, respectively, and let the systems to transmit the informations with each other. Therefore, the novel Tri-duplexer would be good potential candidate not only for nowadays but also for future applications in communication systems.