互補金氧半導體合成耦合傳輸線的分析、設計與應用

Abstract

本篇論文係探討在應用於互補金氧半導體製程中的合成耦合傳輸線的分析、設計與應用。該耦合傳輸線在設計時為了電路縮小化採用了曲折繞線的設計，因此傳統的奇-偶模分析對於此一曲折繞線的非理想對稱的結構並不完全適用。在本論文的第一部分中，非對稱的耦合線模型被使用來分析此一結構，且參數萃取的過程是來自非對稱耦合線的ABCD參數與S參數之間的關係來完成，該模型中的Rc以及Rp兩參數可用以量化地定義耦合線結構的對稱性。此一參數萃取流程應用於一個0.18微米的互補金氧半導體製程上的3 dB方向耦合器，分析結果可以量化地表現出耦合線的對稱性仍然可以很好地被維持住，一些可能造成耦合線對稱性下降的結構也可應用此一模型分析，例如耦合較弱的耦合線及轉角的方向數不同。一種適合在互補金氧半導體上應用的等長度轉角設計也被提出且證實可改進多種不同耦合線結構的對稱性。三條線的耦合線也用類似的方法進行分析，同樣有兩種試圖改善該結構對稱性的三條線轉角也被設計出來並可比較其對不同模態的效果。 第五章中提出對一個在0.18微米的互補金氧半導體製程上使用多導體的合成傳輸線與點對稱螺旋型的高方向性的方向耦合器的設計與分析。此一非均勻的點對稱螺旋型電路採用平行耦合線來模型，使用前述的非對稱耦合線的模型來分析, 可看出此電路只有些微地非對稱，因此這個分析可適用於分析此一非均勻而有空間上的對稱的電路，透過進一步分析採用非對稱的模型會較使用對稱的耦合線模型更能準確的預測這個方向耦合器的方向性。 第六章中描述一種新型的Marchand平衡不平衡轉換器(balun)，此一電路包含合成耦合線以及主動電路，在該電路中適當的連結負電阻電路即可有效的補償耦合線造成的損耗。整體電路特性的推導也已提出。互補式的負阻抗產生器可補償耦合線的損耗並且降低所需的線長。一個操作在24 GHz的Marchand Balun 在0.18微米的互補金氧半導體製程上被設計完成，並可以達到預期的無損耗且反相位的結果且面積為240微米×270微米。

This dissertation presents the analysis, design, and application of the CMOS synthetic coupled transmission lines. The proposed coupled lines are designed in a meandered form for circuit miniaturization. The conventional even-odd mode analysis is not appropriate to apply due to the meandering structure, which is asymmetric. In the first part of this dissertation, the asymmetric coupled-line model is adopted for analyses and the equivalent model parameters are extracted based on asymmetric coupled-line ABCD parameters and S parameters. The Rc and Rp in the model is available for quantitatively define the symmetry of coupled lines. The proposed extraction procedure is then applied on a 3-dB directional coupler on 0.18-um CMOS technology. The results quantitatively show that symmetry of the coupled lines is well maintained. Symmetry of other coupled-line structures that degrade coupled-line symmetry such as loosely coupled lines and different bend direction are also analyzed based on this model. An equal-length bend design suitable for the CMOS synthetic coupled lines is proposed and has managed to improve symmetry on various structures. Three-line coupled lines have also been analyzed with the similar procedure. Two kinds of three-line bends are designed and compared their utility on different modes. Chapter 5 presents the design and analysis of a high directivity coupler using the multi-conductor synthetic lines and interwound-spiral shape in 0.18-um CMOS technology. Parallel coupled lines are used to model the non-uniform point-symmetric interwound spirals. By applying a more general asymmetric coupled-line model, the circuit appears to be slightly asymmetric. The interwound spiral coupler demonstrates that the analysis is capable to be applied on structurally non-uniform circuits with space symmetry. The interwound spirals can be modeled more accurately as asymmetric coupled lines than symmetric ones in the design of high directivity directional couplers. Chapter 6 describes a novel Marchand balun consisting of synthetic coupled lines and active circuits. By properly placing a negative resistance circuit in the Marchand balun, the active circuit is able to compensate the loss of coupled lines. Derivation of the proposed Marchand balun characteristics is provided. The complementary cross-coupled pair compensates the loss of coupled lines and reduces the total line-length required. The proposed Marchand balun operated on 24 GHz is designed and fabricated on 0.18-um CMOS technology. It achieves the desired lossless and out-of-phase balun performance with an area of 240 um × 270 um.