Analysis & Design of Radio Frequency Wireless Communication Integrated Circuits with Nanoscale Double Gate MOSFETs A dissertation presented to the faculty of the Russ College of Engineering and Technology of Ohio University In partial fulfillment of the requirements for the degree Doctor of Philosophy Soumyasanta Laha May 2015 © 2015 Soumyasanta Laha. All Rights Reserved. 2 This dissertation titled Analysis & Design of Radio Frequency Wireless Communication Integrated Circuits with Nanoscale Double Gate MOSFETs by SOUMYASANTA LAHA has been approved for the School of Electrical Engineering and Computer Science and the Russ College of Engineering and Technology by Savas Kaya Professor of Electrical Engineering and Computer Science Denis Irwin Dean, Russ College of Engineering and Technology 3 Abstract LAHA, SOUMYASANTA, Ph.D., May 2015, Electrical Engineering Analysis & Design of Radio Frequency Wireless Communication Integrated Circuits with Nanoscale Double Gate MOSFETs (214 pp.) Director of Dissertation: Savas Kaya Today’s nanochips contain billions of transistors on a single die that integrates whole electronic systems as opposed to sub-system parts. Together with ever higher frequency performances resulting from transistor scaling and material improvements, it thus become possible to include on the same silicon chip analog functionalities and wireless communication circuitry that was once reserved to only an elite class of compound III- V semiconductors. It appears that the last stretch of Moore’s scaling down to 5 nm range, these systems will only become more capable and faster, due to novel types of transistor geometries and functionalities as well as better integration of passive elements, antennas and novel isolation approaches. Accordingly, this dissertation is an example to how RF-CMOS integration may benefit from the use of a novel multi-gate transistors called FinFETs or Double Gate Metal Oxide Semiconductor Field Effect Transistors (DG- MOSFETs). More specifically, this research is to validate how the performance of the radio frequency wireless communication integrated circuits can be improved by the use of this novel transistor architecture. To this end, in this dissertation, a wide range of radio frequency integrated circuits have been investigated in DG-MOSFETs which include Oscillators, On Off Keying (OOK) Mod- ulator, Power Amplifier, Low Noise Amplifier, Envelope Detector, RF Mixer and Charge Pump Phase Frequency Detector. In all cases, the use of DG-MOSFET devices lead to reduction of transistor count and circuit complexity, while also resulting in tunable circuits owing to local back-gate control available in this device structure. Hence this work pro- vides a unique insight as to how modest geometry changes and 3D device engineering may 4 result in significant gains in analog/RF circuit engineering in the last stretch of Moores scaling. 5 To the memory of my father, Bhanu Kumar Laha and grandfather, Sudhanshu Sekhar Laha 6 Acknowledgments I wish to express my sincere gratitude to my advisor, Prof. Savas Kaya for his valuable guidance and supervision in the development of the dissertation. He has been always friendly yet rigorous with my research progress which helped me in the achievement of the research goal. His tremendous energy and enthusiasm towards any academic venture is truly commendable and has taught me many lessons for my future endeavor. Also grateful to him for providing the necessary financial support as research assistantship during the course of my research. I am extremely grateful to my committee members, Prof. Chris Bartone, Prof Jeffrey Dill and Prof. Avinash Kodi for their valuable academic guidance in the final progress of the dissertation. Their familiarity with the ideas, needs of the subject and effective suggestions are a contributing factor to the development of the dissertation. I also extend my warm gratitude to my external committee members Prof. Sergio Ulloa of Department of Physics and Astronomy and Prof. Martin Mohlenkamp of Department of Mathematics for their inquisitiveness and appraisal towards my work in the last laps of the dissertation. Special thanks to Prof. Jerrel Mitchel, currently a retired professor, for considering me for the 21 month endowed ‘Stocker Research Fellowship’ during the admission in his capacity as the Graduate Chair of the department, that stands out to be an important reason to choose the university for my PhD study. My heartfelt thanks also goes to Prof. David Matolak, for providing me the Teaching Assistantship for two academic years in his capacity as the Graduate Chair of our department. Later, as a collaborator cum mentor of an NSF sponsored research project, his suggestions in weekly meetings have helped me to gain a clear and total understanding of the project. 7 My sincere gratitude goes to the university program of Synopsys and Cadence Design Systems, which helped in carrying out the EDA simulations necessary for the research. My special gratitude goes to Keysight Technologies (Agilent) for providing complementary access to their ADS software. I am also thankful to MOSIS for providing access to 65 nm and 130 nm RF CMOS process technologies from IBM and to Win Semiconductor for access to their III-V pHEMT technology process. I also remember the wonderful moments that I have spent with all my colleagues during the course of the dissertation. Finally, I am indebted to my parents, my wife and my brother for their continuous support and motivation towards the progress of this dissertation. 8 Table of Contents Page Abstract ......................................... 3 Dedication ........................................ 5 Acknowledgments .................................... 6 List of Tables ...................................... 12 List of Figures ...................................... 13 1 Introduction & Motivation ............................. 19 1.1 Wireless Communication ........................... 19 1.2 Integrated Circuits .............................. 21 1.3 Novel Multi-Gate & 3D Transistors ..................... 22 1.4 Research Goals & Accomplishments ..................... 24 1.4.1 Research Goals ............................ 24 1.4.2 Accomplishments ........................... 25 1.5 Dissertation Organization ........................... 28 1.6 Analysis & Design Tools ........................... 29 2 Background ..................................... 32 2.1 MOSFET Fundamantals ........................... 32 2.1.1 MOSFET Operation ......................... 32 2.1.2 I-V Characteristics .......................... 34 2.1.3 Complementary MOS Architecture ................. 35 2.1.4 Power Dissipation .......................... 36 2.1.5 MOSFET Scaling ........................... 37 2.2 Evolution to Multigate MOSFETs ...................... 38 2.2.1 Limitations of CMOS ........................ 38 2.2.2 Advanced CMOS ........................... 40 2.2.2.1 Strained Silicon ...................... 41 2.2.2.2 SOI Technology ...................... 42 2.2.2.3 Multigate MOSFETs ................... 42 2.3 DG-MOSFET Basics ............................. 44 2.3.1 Device Models ............................ 47 2.3.2 Small Signal Circuit Models ..................... 49 2.4 Microwave Basics ............................... 51 2.4.1 RF Figure of Merits ......................... 51 2.4.2 Non-Linearity ............................. 52 9 2.4.2.1 Harmonic Distortion .................... 52 2.4.2.2 Gain Compression ..................... 53 2.4.2.3 Intermodulation ...................... 54 2.4.3 Noise ................................. 57 2.4.3.1 Randomness and Noise Spectrum ............. 57 2.4.3.2 Device Noise ........................ 57 2.4.3.3 Noise in Circuits ...................... 59 2.4.4 Sensitivity & Dynamic Range .................... 60 2.4.4.1 Sensitivity ......................... 60 2.4.4.2 Dynamic Range ...................... 60 2.4.5 Scattering Parameters ......................... 61 2.4.6 Passives ................................ 64 2.4.6.1 Resistors .......................... 64 2.4.6.2 Capacitors ......................... 65 2.4.6.3 Inductors .......................... 67 2.4.6.4 Microstrip Transmission Lines .............. 70 2.4.7 Impedance Matching ......................... 72 2.5 Wireless Communication ........................... 76 2.5.1 Modulation Fundamentals ...................... 76 2.5.1.1 Amplitude Shift Keying .................. 76 2.5.1.2 Phase Shift Keying .................... 77 2.5.1.3 Orthogonal Frequency Division Multiplexing ....... 79 2.6 Wireless Transceiver ............................. 80 2.6.1 Basic Architecture .......................... 80 2.6.2 System Level Design ......................... 82 2.6.3 Link Budget Analysis ........................ 86 3 DG-MOSFET OOK Transmitter .......................... 89 3.1 Introduction .................................. 89 3.2 Oscillators ................................... 89 3.2.1 Oscillator Fundamentals ....................... 91 3.2.2 LC Oscillator ............................. 93 3.2.3 Relaxation Oscillator .........................102 3.3 OOK Modulator ................................108 3.4 Power Amplifier ................................109 3.4.1 Power Amplifier Basics .......................110 3.4.2 Power Amplifier Design .......................111 3.4.3 Simulation Results ..........................114 3.5 Summary ...................................117 10 4 DG-MOSFET OOK Receiver ............................120 4.1 Introduction ..................................120 4.2 Low Noise Amplifier .............................120