應用互補裂隙矩形共振腔於新型複合式左右手寬頻任意耦合量設計之方向耦合器

Abstract

本論文主要以裂隙矩形共振腔為電路基礎，提出兩大類任意耦合量傳輸線耦合器設計。其中包含非對稱型相位耦合器、新型單頻方向選擇耦合器以及雙頻方向選擇耦合器。裂隙矩形共振腔是一種後設材料，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及天線設計上。 論文前半部利用裂隙矩形共振腔(complementary split-rectangle resonators, CSRR)實現複合式左右手傳輸線(composite right/left-handed transmission line, CRLH)，並配合耦合模理論(coupled-mode theory , CMT)提出應用互補式裂隙矩形共振腔之耦合器縮小化概念及非對稱型相位耦合器設計。其擁有相當高的耦合量及方向性，且可藉由結構彈性大的裂隙矩形共振腔作電路尺寸縮小化的設計。 論文後半部同樣利用裂隙矩形共振腔實現所需的電路單元，且另外提出創新的類傳輸線耦合概念，並充分運用此概念設計出新型單頻方向選擇耦合器以及雙頻方向選擇耦合器，此耦合電路不僅可達到高耦合量及方向性，甚至能打破傳統耦合理論的限制，大幅的增加耦合頻寬，且達到電路縮小化的效果。 在本研究中，新型CRLH方向耦合器無論在耦合量、隔離度或是耦合頻寬的表現上都遠比一般傳統耦合器突出，所提出的類傳輸線耦合概念甚至能解決以往微波電路設計的矛盾(trade-off)。在保持優良的耦合效能下，大幅縮小電路尺寸，並增加與其它電路的整合性。

In this thesis, we propose the design of coupled-line directional coupler with arbitrary coupling level based on complementary split-rectangle resonators (CSRR), which can be broadly classified into two major categories. The directional coupler includes an asymmetry phase coupler and two novel directional couplers, which are designed for single band and dual band. Complementary split-rectangle resonator, which is one kind of the meta-materials exhibits unique electromagnetic properties that lead to a wide range of application in design of microwave circuit and antenna. In the first part of this thesis, a CRLH transmission line is implemented by utilizing the CSRR. And then we adopt the coupled-mode theory based on the new structure to propose the concept of size reduction and design of the asymmetry phase coupler. This coupler exhibits the superior coupling and direction; furthermore, its size also can be reduced by means of CSRR. In the last part of this thesis, a novel coupled line concept based on CSRR is proposed, and realized the single-band and dual-band couplers which feature not only high coupling and direction, but also breakthrough of the conventional coupled way to increase the coupling bandwidth and even miniature the circuit. In the research, the coupling, isolation, and bandwidth of the novel CRLH directional coupler are more excellent than conventional couplers. Furthermore, the novel coupled line concept we propose can solve the trade-off in the microwave circuit design. Under the fine coupling potency, it can reduce the size of coupler largely, and increase the integration with other microwave circuit.