有限厚度之開槽式圓形波導之裂模現象的場論分析

Abstract

本論文以嚴謹的全波方法來分析有限厚度的金屬封包圓形波導的傳播特性 。於文中，一個最一般化的特徵函數用來展開波導□面的場，而且開槽式 波導的裂模現象首度被提出。首先將對模展開法的相對收斂特性作廣泛的 探討，並且將其在開槽很小且封包金屬很接近開槽式波導時的離散特性和 傳統的圓形波導作比較。接著將金屬厚度和金屬封包對正規化的傳播常數 的影響作深入的探討。總之，本論文對於開放式開槽圓形波導的輻射現象 的了解與預測非常有幫助，它可用來預測開槽式圓形波導的何種模適合用 來設計天線. In this thesis, a rigorous full-wave mode-matching method is used to analyze the propagation characteristics of a conductor bounded slotted circular waveguide which has finite thickness. A most general eigenfunction expansion formulation is proposed and the concept of mode splitting is presented for the first time. Extensive convergence studies for the mode-matching method are presented and the dispersion relation for a limiting case is presented and compared with that of a conventional circular waveguide. The effects of the metal thickness and the cylindrical conducting enclosure on the normalized propagation constants are also performed. In summary, this thesis is helpful in the prediction and understanding of the radiation mechanism of a slotted waveguide. With the help of this computer program, one can predict what kind of modes would radiate easily from a slotted circular waveguide.