本論文以微型化三頻微波被動電路設計為研究目標，提出使用三頻橋式T線圈(Bridged-T Coil, BTC)實現三頻等效傳輸線的設計方法，成功實現積體化之三頻分支線耦合器及威爾金森功率分配器。本研究在現有的三頻橋式T線圈設計理論基礎上，進行設計方式的優化，有效改善先前設計中第一操作頻率的頻偏問題。設計優化前所完成之9.4 / 19 / 25 GHz三頻分支線耦合器，雖然電路面積僅1.643 mm × 1.726 mm，但其第一操作頻率與設計目標11.5 GHz相比有2.1 GHz的頻偏。本研究所提出的第一種設計優化方式，是以三個橋式T線圈串接實現三頻等效傳輸線，並應用於微型化三頻威爾金森功率分配器的設計，其操作頻率為6.7 / 14.2 / 17.6 GHz，電路面積僅0.805 mm × 1.33 mm，其第一操作頻率相較於設計目標8 GHz的頻偏降為1.3 GHz。而第二種設計優化方式則採用四個橋式T線圈串接組成三頻等效傳輸線，並據以實現微型化之三頻威爾金森功率分配器，其操作頻率為6.7 / 14.5 / 18.4 GHz，電路面積僅0.88 mm × 1.33 mm，其第一操作頻率相較於設計目標8 GHz亦只有1.3 GHz的頻偏。此外，相較於既有三頻威爾金森功率分配器設計，本研究所提出之兩種設計均成功達成大幅縮減電路面積之目的。;This thesis focuses on the design of miniaturized tri-band microwave passive circuits using bridged-T-coils (BTC). Specifically, miniature tri-band branch-line coupler and Wilkinson power divider designs are demonstrated. Especially, this research improves the design methodology such that the frequency shift at the first operating frequency in previous designs can be much reduced. First, a tri-band branch-line coupler operating at 9.4 / 19 / 25 GHz was realized with a compact circuit size of only 1.643 mm × 1.726 mm. However, its first operating frequency exhibited a 2.1 GHz deviation from the design target of 11.5 GHz. To reduce the frequency shift, the first method is to use three bridged-T-coils in cascaded to realize a tri-band equivalent transmission line. It is then applied to the design of a miniaturized tri-band Wilkinson power divider operating at 6.7 / 14.2 / 17.6 GHz, achieving a compact circuit size of just 0.805 mm × 1.33 mm. The frequency shift of the first operating frequency is reduced to 1.3 GHz from the design target of 8 GHz. Next,the second method for reducing the frequency shift employs four bridged-T-coils in cascade to form a tri-band equivalent transmission line. It is also applied to the design of a miniaturized tri-band Wilkinson power divider operating at 6.7 / 14.5 / 18.4GHz, and a very compact circuit size of only 0.88 mm × 1.33 mm is achieved. The shift in first operating frequency is also 1.3 GHz from the design target of 8 GHz. In addition,compared to existing tri-band Wilkinson power divider designs, the proposed ones achieve significant reduction in circuit size.
