本論文提出了基於基板合成波導理論的岐管饋入結構，並利用此結構設計出多工器、四通帶雙工器等電路。 第一個多工器電路是中心頻率為分別為9.5/9.85/10.15/10.55/10.85 GHz 的五通帶多工器，透過五個基板合成波導單頻帶帶通濾波器結合岐管結構設計而成。首先，設計五個中心頻率依序為 9.5GHz、9.85GHz、10.15GHz、10.55GHz、10.85GHz 的單頻帶帶通濾波器，結構上採用正方形全模基板合成波導共振器，使用的模態是 TE101，並在輸出端口採用錐形轉接結構來滿足設計規格所需之外部品質因數。接著分析每一個通道對應之 T 型介面，透過調整相鄰通道之間的距離，可以使該 T 型介面的另一端輸入阻抗為零，使能量都能順利由岐管主幹流入各通道，達到最好的輸入匹配效果。待輸入端匹配完成後，最後微調各通道濾波器之輸入端與輸出端之外部品質因數與共振器之間的耦合係數，完成五通帶多工器。 第二個電路是將基於前述理論設計出之四工器進行改良，將原第一與第三個通道之輸出端透過基板合成波導 T 型接面結合、原第二與第四個通道之輸出端口以岐管結構結合，再基於第三章的步驟，對兩個岐管主幹以及輸出端之 T 型介面進行分析，最後同樣再微調各通道濾波器之輸入端與輸出端之外部品質因數與共振器之間的耦合係數，完成四通帶雙工器。;This thesis introduces the application of substrate integrated waveguide (SIW) technology base on manifold structure to implement two distinct diplexers. The first circuit is a five channel multiplexer with center frequencies at 9.5/9.85/10.15/10.55/10.85 GHz. It is realized by combining five single-band SIW bandpass filters with a manifold structure. Each filter is designed using a square full-mode SIW cavity resonator operating in the TE101 mode, and a tapered transition is implemented at the output port to achieve the required external quality factor. The T-junction interface for each channel is then analyzed. By adjusting the distances between adjacent channels, the input impedance at the remaining port of each T-junction can be made zero, allowing energy to efficiently flow from the manifold structure to each channel, thereby achieving optimal input matching. After ensuring proper input matching, the external quality factors at the input and output ports of each channel and the coupling coefficients between resonators are fine-tuned to complete the five-channel multiplexer design. The second circuit is an improved design based on the manifold quadplexer. The output ports of the first and third channels are combined through a SIW T-junction, while those of the second and fourth channels are combined using a manifold structure. The two manifold structures and the T-junction at the output side are analyzed by the procedures described in Chapter 3. As with the previous design, the external quality factors and coupling coefficients are fine-tuned to complete the quad-band diplexer.
