本論文將一款人工合成傳輸線，以對稱型式及非對稱型式實現，並將此傳輸線應用於環形共振器結構，以完成微型化雙模態帶通濾波器之設計。論文首先針對環形共振器的基本設計原理與架構作一討論。其次，則詳盡分析此人造合成傳輸線之設計原理、集總等效電路、模擬與量測結果、以及其非線性相位變化之特性。
利用非對稱型式之人工合成傳輸線，吾人實現可抑制諧波效應之微型化雙模態單頻帶通濾波器，此帶通濾波器之電路面積僅有0.167 λg × 0.087 λg，相較於傳統環形帶通濾波器，其面積減少85.5%。藉由人工合成傳輸線及帶通濾波器之齒狀耦合結構所引入之多重傳輸零點，此濾波器可達頻寬諧波抑制效果。
利用對稱型式之人工合成傳輸線，吾人則設計一款微型化可調雙模態雙頻帶通濾波器。此雙頻帶通濾波器之電路面積僅有0.186 λg ×0.123 λg，為傳統環形濾波器之22.5%。吾人藉由改變人工合成傳輸線之指插電容值，可有效控制傳輸線之截止頻率及非線性相位，亦可決定雙頻帶通濾波器之雙通帶中心頻率及其頻率比，冀以提升此微型化雙模態雙頻帶通濾波器之可調性及適應性。

Novel miniaturized ring dual-mode bandpass filters are developed by utilizing artificial transmission lines in either symmetrical or asymmetrical form. The miniaturized designs are developed by replacing the transmission lines in the ring resonators by artificial ones. The essentials of the ring resonators, which include the design principles and structures, are first discussed. The artificial transmission lines are then investigated in detail in terms of the design concepts, lumped equivalent circuit model, simulated and measured results, and the nonlinear phase responses.
A miniaturized ring dual-mode single-band bandpass filter with harmonic suppression characteristics is designed with the asymmetrical artificial transmission lines. The circuit size of the filter is merely 0.167 λg × 0.087 λg, which corresponds to a size reduction percentage of 85.5% as compared with a conventional design. By introducing multiple transmission zeros with the asymmetrical artificial transmission lines and the modified input/output saw-toothed coupling structures, the proposed filter demonstrates wideband harmonic suppression characteristics.
A miniaturized ring dual-mode dual-band bandpass filter using symmetrical artificial transmission lines is also proposed and discussed. The circuit size of the filter is 0.186 λg × 0.123 λg, which is only 22.5% the size of a conventional ring dual-mode filter. By simply adjusting the interdigital capacitance values of the artificial transmission lines, the cut-off frequencies and nonlinear phase response of the artificial lines can be readily controlled, which in turn determine the center frequrncies of the first and second passbands of the filter and the associate frequency ratio between them. The tunability and flexibility of the proposed miniaturized ring dual-mode dual-band filter are therefore improved.

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