Design and Application of Synthetic Quasi-TEM Lines

在本論文中，提出一種新型合成傳輸線。此種二維傳輸線係由介質基板及上、下兩層互補式的金屬圖案所構成，這種合成傳輸線能提供我們所需要的電氣特性。比較此合成傳輸線與傳統微帶線的電氣特性，在不改變上層金屬的寬度下，不論是在理論值或實際量測值上，此合成傳輸線的特徵阻抗比傳統微帶線高出130%，且慢波係數也比物理上的理論值高出17.7%。 利用上述的合成傳輸線設計一個Ka-band的rat-race hybrid，與傳統rat-race hybrid相比，有三大優點 : 1) 這個hybrid有相當好的隔離度 2) 很小的反射損耗 3) 面積小。這個利用二維合成傳輸線排列的hybrid面積，不包括pad的話，只有600 x 460 um2。 最後，提出一個X-band結合交越耦合與利用合成傳輸線型式電感之壓控振盪器，使用0.18微米CMOS製程。此壓控振盪器的面積僅有470 x 510 um2，其10.2GHz在1 MHz位移相位雜訊為 -107 dBc/Hz。In this thesis, a new synthetic quasi-TEM (Transverse Electromagnetic) transmission line (TL) is presented. The proposed synthetic TL consists of a two-dimensional array made of complementary-conducting strips (CCS) unit cell, which permits tuning for desired propagation characteristics of the transmission line under synthesis. Based on the particular case study, both theoretical and measured results agree excellently for the comparative studies for the proposed synthetic TL and the conventional microstrip. The Zc of a synthetic TL is 130% higher than that of a wide microstrip. Furthermore, the extracted slow-wave-factor is 17.7% higher than the physical limit of microstrip. In addition, a Ka-band CMOS rat-race hybrid using the synthetic quasi- TEM TL is proposed. Comparing with the conventional rat-race hybrid, the synthetic TL-based rat-race hybrid features 1) good isolation, 2) reflection loss, and 3) a compact structure. This hybrid incorporates two-dimensional (2D) meandering CCS TL whose size is only 600 x 460 um2 excluding RF pads. Finally, an X-band VCO combining cross-coupled pair and CCS-TL based inductors topology is proposed. The circuit is fabricated by 0.18-Table of Contents Acknowledgement……………………………………………………………………ii Chinese Abstract ……………………………………………………………………iii English Abstract……………...……………………………………………….............iv Table of Contents……………………………………………………………………..v List of Figures…………….…………………………………………………………..vi List of Table…………………………………………………………………………...xi 1 Introduction 1.1 Motivation and Literature Survey…………………………………………….1 1.2 Thesis Organization……………………………………………………………2 2 Applications of Various Synthetic Structures 2.1 Applications of Various Synthetic Structures………………………………...3 2.1.1 High-Impedance Electromagnetic Surface (HIS)…………………….....3 2.1.2 Frequency Selective Surfaces (FSS)……………….……………………...8 2.1.3 Uniplanar Compact Photonic Bandgap Structure (UC-PBG)…………...10 2.1.4 Photonic Bandgap Structure (PBG)………………………………..……12 3 Synthetic Quasi-TEM Transmission Line: Complementary-Conducting Strip Transmission Line 3.1 Quasi-TEM Transmission Line: Conventional Microstrip Line………….…...14 3.2 Complementary-Conducting Strip Transmission Line (CCS TL)……………..16 3.3 Design of One-Dimensional Synthetic Quasi-TEM Transmission Line and Scale-up Model………………………………………………………..…….…19 3.3.1 Measurements……………………………………………………………20 3.3.2 Summary………………………………………………………………...23 3.4 Thin-Film Microstrip Line and CCS TL………………………………………24 4 A Miniaturized Ka-Band CMOS Rat-Race 4.1 Conventional Rat-Race Hybrid………………………………………………..28 4.2 A Compact Ka-Band CMOS Rat-Race Hybrid Using CCS TLs……………...30 4.2.1 A Compact CCS TL-based Rat-Race Hybrid……………………………31 4.2.2 Measurements……………………………………………………………33 4.2.3 Summary……………………………………………………………...…36 5 An X-band Voltage-Controlled Oscillator 5.1 Voltage-Controlled Oscillator……………………………………………37 5.1.1 Figures of Merit for VCO……………………………………………….37 5.1.2 Cross-Coupled Pair VCO……………………………………………….40 5.1.3 Quality (Q) of LC Tank…………………………………………………43 5.2 An X-band Voltage-Controlled Oscillator Using CCS TLs…………………..46 5.2.1 Noise Comparison of PMOS and NMOS……………………………….46 5.2.2 The CCS TL-based on- chip Inductor and MOS Varactor………………47 5.2.3 The Proposed X-band Voltage-Controlled Oscillator Using CCS TLs.51 5.2.4 Measured Results..………………….…….……………………………..52 6 Conclusion…………………………………………………………………………55 References……………………………………………………………………………5