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Distributed Power Amplifiers for Software Defined Radio Applications

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Distributed Power Amplifiers for Software Defined Radio Applications Distributed Power Amplifiers for Software Defined Radio Applications Von der Fakultät für Elektrotechnik und Informationstechnik der Rheinisch-Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Ingenieurwissenschaften genehmigte Dissertation vorgelegt von Narendra Kumar, M.Sc B.E(Hons) aus Penang, Malaysia Berichter: Univ.-Prof. Dr.-Ing. Rolf H. Jansen Univ.-Prof. Dr.-Ing. Dirk Heberling Univ.-Prof. Ernesto Limiti Tag der mündlichen Prüfung: 23. Mai 2011 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar i Acknowledgements I would not be able to complete this thesis without the support of numerous individuals and institutions e.g. Prof. Dr.-Ing. Rolf H. Jansen (RWTH Aachen University, Germany), Bob Stengel (Motorola Labs, Florida, US), Chacko Prakash (Motorola Research Center, Malaysia), Prof. Ernesto Limiti (University Roma Tor Vergata, Italy), Prof. Claudio Paoloni (University Roma Tor Vergata, Italy), Prof. Juan-Mari Collantes (University of Basque Country, Spain), Prof. Yarman Siddik (Istanbul University, Turkey), Thomas Chong ((Motorola Research Center, Malaysia), Dr. Vitaliy Zhurbenkho (Technical University Denmark, Denmark). I would like to express my special gratitude to Prof. Dr.-Ing. Rolf H. Jansen, the head of the Chair of Electromagnetic Theory (ITHE), RWTH Aachen University, for giving me the opportunity and the freedom to complete my Ph.D research under his supervision. Also, I would like to thank him for supporting me with the insight in academic aspects and the fruitful discussions. I am grateful to Prof. Dr.-Ing. Dirk Heberling to be co-referee and Prof. Ernesto Limiti as an external examiner for my thesis examination. In addition, I am grateful to Motorola Education Assistance Board (Lee SiewYin, Fam FookTeng, Dr. Hari Narayan, Chacko Prakash, and the team) for providing financial support. Special thank to Prof. Claudio Paoloni for his help in reviewing my thesis and provide comments. Also, sincere gratitude to Fam FookTeng, Chacko Prakash and Joey Ooi (Motorola Research Center, Florida, US) for their encouragement and motivation given during my work. My sincere gratitude extends to my parents, beloved wife and all my colleagues and friends for their kind assistance and support, including Aridas, Indra, Sangeran, Banu, Phuvaneswary, Pragash, Lokesh, Maisarah, Sathish Arumugam, Jesus Cumana, Jens Goliasch, Christian Lautensack, Sun Golian, Koh BoonPing, Solomon Lorthu, Macwien Krishnamurthy, Mohd. Fadli, Joshua Lee, Tan TiekSiew, Prabakar, Mahadev, Kogilavani, Megalah, Yogeswaran, Jeevan Kanesan, Harikrishnan, Ramesh Kumar, Shankar Karuppayah and Loganathan. ii Contents List of Acronyms and Symbols …………………………………………………………………………………vi List of Figures ….………………………………………………………………. …………………………………ix List of Tables ….………………………………………………………………. …………………………………xvi 1 Introduction ......................................................................................................................................... 1 1.1 Objective of This Work ............................................................................................................ 1 1.2 Thesis Organization ................................................................................................................ 2 2 Broadband Amplifier Limitations and Designs................................................................................ 3 2.1 Bandwidth Limitation Analysis ................................................................................................. 3 2.2 Broadband switched-mode amplifier ....................................................................................... 5 2.2.1 Parallel-circuit class E with reactance compensation technique ............................................ 5 2.2.2 Excessive capacitance absorption with shunt C-LC network ................................................. 7 2.3 Broadband High Linearity and Efficient amplifier .................................................................. 10 2.4 Multi-stage broadband amplifier ............................................................................................ 11 2.5 Balanced amplifier (BA) ........................................................................................................ 12 2.6 Unified Broadband Matching Approach ................................................................................ 14 2.7 Conclusion ............................................................................................................................. 15 3 Distributed Amplification Concept and Practical Distributed Amplifiers Design methodology .. ............................................................................................................................................................ 16 3.1 Concept of Distributed Amplification ..................................................................................... 16 3.1.1 Introduction ............................................................................................................................ 16 3.1.2 Image impedance method ..................................................................................................... 18 3.2 Theoretical Analysis of DA .................................................................................................... 20 3.2.1 Analytical approach of Beyer model (Two-port theory) ......................................................... 21 3.2.2 Analytical approach of Niclas model (Admittance matrix) ..................................................... 23 3.2.3 Analytical approach of McKay model (Wave theory) ............................................................ 25 3.3 Gain/ Power-bandwidth trade-off .......................................................................................... 27 3.4 Design Methodology of Practical DA .................................................................................... 31 3.5 Conclusion ............................................................................................................................. 39 4 Efficiency Analysis in Distributed Amplifier .................................................................................. 40 4.1 Efficiency Limitations in DA ................................................................................................... 40 4.2 Virtual Impedance analysis due to multi current sources ..................................................... 41 4.3 High Efficiency DA Development .......................................................................................... 50 4.3.1 Simulation Analysis ............................................................................................................... 50 4.3.2 Design Example of High Efficiency DA ................................................................................. 52 iii 4.3.3 Broadband Impedance Transformer Design ......................................................................... 56 4.3.4 Measurement Results ........................................................................................................... 61 4.4 Dual Fed DA with Termination Adjustment ........................................................................... 64 4.4.1 Motivation .............................................................................................................................. 64 4.4.2 Principle Operation ................................................................................................................ 64 4.4.3 Design Example of DFDA with termination adjustment ........................................................ 69 4.4.4 Measurement Results ........................................................................................................... 73 4.5 Conclusion ............................................................................................................................. 75 5 Stability Analysis in Distributed Amplifiers ................................................................................... 76 5.1 Motivation of Stability Analysis .............................................................................................. 76 5.2 Stability Analysis Methods .................................................................................................... 77 5.2.1 K-factor stability of a two port network .................................................................................. 77 5.2.2 Feedback and NDF factor ..................................................................................................... 79 5.2.3 Pole-zero identification method ............................................................................................. 82 5.3 Analysis and Conditions of Stability in DAs .......................................................................... 83 5.4 Parametric oscillations detection in DAs ............................................................................... 91 5.4.1 Introduction ............................................................................................................................ 91 5.4.2 Stability Analysis of DA ......................................................................................................... 91 5.4.3 Circuit Stabilization and Measurement Results .................................................................... 93 5.5 Conclusion ............................................................................................................................
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