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Title: Load Redistribution Attacks and Protection Strategy Design in Electric Power Systems
Creator: Yuan, Yanling
Date: 2012-04-27, 2012-05
Description: Electric power systems have evolved over the past century to the largest and the most complex cyber-physical systems. With the development of...
Show moreElectric power systems have evolved over the past century to the largest and the most complex cyber-physical systems. With the development of Smart Grid, cyber security has become an area of growing concern. False data injection attack has recently attracted wide research interest. This thesis develops the concept of load redistribution attack, a special type of false data injection attack. The physical and economic impact of load redistribution (LR) attacks is quantitatively analyzed in this thesis. Since LR attacks can successfully bypass bad data detection and manipulate the state estimation outcome, security constrained economic dispatch (SCED) based on the false state estimation would lead the system into a non-optimal or insecure operation state. Based on the consequence analysis, two different attacking goals are differentiated from the adversary’s perspective, i.e., immediate attacking goal and delayed attacking goal. For the immediate attacking goal, a max-min attacker-defender model is proposed to identify the most damaging immediate LR attack. Two different algorithms are used to solve this bi-level optimization problem. For the delayed attacking goal, a tri-level model is proposed to identity the most damaging delayed LR attack. This thesis studies the economic impact of LR attacks on power market operation. A convex model is proposed under the mechanism of virtual bidding to compute the optimal injection of LR attack, which gains the most profit from the attackers’ perspective. The quantitative analysis of LR attacks provides an in-depth insight on effective attack prevention with limited protection resource budget. This thesis proposes a new protection strategy, which intends to mitigate the most damaging effect of LR attacks on power system operation. The criterion of determining effective protections against the most damaging LR attack, considering the existence of stochastic measurement errors, is deduced.
Ph.D. in Electrical Engineering, May 2012
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Title: LOW POWER METHODOLOGIES USING UNIFIED POWER FORMAT
Creator: Varsha
Date: 2012-11-14, 2012-12
Description: This thesis would be incomplete without the mention of people who made it possible and encouraged me at every step along the way. I would like...
Show moreThis thesis would be incomplete without the mention of people who made it possible and encouraged me at every step along the way. I would like to thank Spenser for helping me with the scripts, design of the architectures and always being ready to assist timely with so many issues. My immense gratitude goes to my advisor and mentor Dr. Erdal Oruklu, who pushed me at every step to achieve my best, drove me to explore new avenues, think new ideas and rethink old ones. I am truly thankful to him for his guidance, believing in me and giving me this opportunity to work under him. Thanks to my committee members Dr. Jafar Saniie and Dr. Tricha Anjali for their insights and suggestions. My heartfelt thanks goes to Hirva, Sneha, Pavan, Sagar, Mateen, Pooja and Neha for their continued support and encouragement throughout. Special thanks to Pavan and Sagar for assisting with the architectures and Mateen for helping with the documentation. Thanks to Krishna for being the go-to person for LATEX issues and always being there to help. Thanks to Santhosh and innumerous friends and acquaintances who helped unconditionally in so many ways. My family has been instrumental in the execution of my thesis. Thanks to my sister for inspiriting me, my brother-in-law for his endless encouragement and advice, their continued support along with my uncle, and my family for standing by me. Finally, this thesis is dedicated to my parents, for never giving up on me, believing in me and letting me pursue my dreams.
M.S. in Electrical Engineering, December 2012
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Title: REAL-TIME FACEDETECTION ANDRECOGNITION SYSTEM INCOMPLEX BACKGROUNDS
Creator: Zhang, Xin
Date: 2015, 2015-07
Description: This report provides a fast and reliable system for real-time face detection and recognition in complex backgrounds. Most current face...
Show moreThis report provides a fast and reliable system for real-time face detection and recognition in complex backgrounds. Most current face recognition systems identify faces under constrained conditions, such as constant lighting condition, the same background. In the real world, people need to be recognized in complex backgrounds under different conditions, such as tilted head poses, various facial expressions, dark or strong lighting conditions. Meanwhile, because of large amounts of real-time applications for face recognition, such as intelligent robot, unmanned vehicle, security monitor, the fast face recognition rate needs to be satisfied for the real-time requirement. In this project, a fast and reliable system is designed to real-time detect and recognize faces under various conditions. Frames are obtained directly from VGA camera. Image preprocessing and face detection, collection, recognition are sequentially implemented on the frames. Local binary patterns and Haar features are used for face detection and eye detection. Local binary pattern encodes every pixel of the image for texture extraction, which is several times faster than Haar feature detection. Adaptive boosting algorithm is used for selecting the best weak classifiers and cascading method divides the extracted best classifiers into several stages to enhance detection rate. Affine transformation is implemented to unify the size of detected facial images and align two eyes to the desired position for improving recognition accuracy. 3􀁵3 Gaussian filter is designed to remove noises of the pre-processed facial images. Principal component analysis (PCA) is used for face recognition, which is fast to identify high-dimensional faces with few principal components.
M.S. in Electrical Engineering, July 2015
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Title: Study of a single-phase variable speed shunt induction motor
Creator: Calvin, R., Zeisler, L
Date: 2009, 1910
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/studyofsinglepha00calv
Thesis (B.S.)--Armour Institute of Technology

Title: Design of a 20,000 kW steam turbo-generator station
Creator: Emmons, Gilbert C., Tellin, William G, Todd, Samuel R
Date: 2009, 1911
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/designof20000kws00emmo
Thesis (B.S.)--Armour Institute of Technology

Title: NATURAL GAS STORAGE EVALUATION FOR GAS FIRED POWER PLANT OPERATION
Creator: Nan, Sibo
Date: 2014, 2014-12
Description: Gas generation has been the preferred non-renewable generation technology during the last few years due to its high efficiency, low emission,...
Show moreGas generation has been the preferred non-renewable generation technology during the last few years due to its high efficiency, low emission, and good flexibility. As a result of increasing gas usage by gas fired power plant (GFPP), gas pipeline congestion becomes a big issue for GFPP. As non-electric natural gas consumers have higher priority in pipeline capacity usage, GFPP’s profit could be negatively impacted when non-electric gas consumption is extremely high. Natural gas storage directly connected to GFPP can supply gas when pipeline capacity is constrained. This thesis presents a model of evaluating the benefit of gas storage to GFPP. The model is formulated as a mixed-integer quadratic programming (MIQP) problem and solved using a commercial MIQP solver. A case study on one GFPP owning 4 natural gas generators is performed based on this model. It is observed that GFPP with gas storage directly connected can make more profit than GFPP without storage. A sensitivity study is conducted to analyze the relationship between the optimal gas storage capacity, as well as GFPP profit, and electricity price, non-electric gas consumption, and gas pipeline contract price. It is observed that the optimal gas storage capacity increases when electricity price increases and available pipeline capacity declines; however it does not change with the variation of gas pipeline contract price. It is also observed that the maximum profit of GFPP is most sensitive to electricity price, then non-electric gas consumption, and is least sensitive to gas pipeline contract price. The main application of this model is to help GFPP owner determine whether or not to install gas storage and, if yes, what the optimal capacity of gas storage should be. In addition, this model can also help GFPP owner plan gas purchase and gas pipeline capacity contract volume.
M.S. in Electrical Engineering, December 2014
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Title: HIGH PERFORMANCE AND LOW POWER HARDWARE IMPLEMENTATION FOR CRYPTOGRAPHIC HASH FUNCTIONS
Creator: Zhang, Yunlong
Date: 2013-04-30, 2013-05
Description: In this thesis, we introduce hash encryption functions which are widely used in a number of protocols as digital signature to protect privacy...
Show moreIn this thesis, we introduce hash encryption functions which are widely used in a number of protocols as digital signature to protect privacy information. Since the hash algorithm can be speeded up and be more security by physical protection, hash function hardware implementation is more desired today for evaluating its performance and processing data with dramatically increased size. Then we consider those two problems in the hash function hardware implementation: throughput and power consumption. High level of throughput is significant for the efficiency of hash algorithm. By using unfolding transformation, the throughput of hash function can be increased apparently. However, power consumption, area and critical path delay will also be increased. Pipeline and parallelism is an effective technique to decrease the critical path delay, by analyzing the construction of computing process. Another Problem is power consumption which will influence the reliability and cost of device. Clock gating is a widely used and efficiency technique for dynamic power reducing at register transfer level (RTL). There are two basic modes for single level clock gating: XOR-based clock gating and load-enable based clock gating [13]. The former one is based on the comparing between output and input of flip-flops (FFs). Although this XOR-based clock gating technique is not used in our hash function hardware implementation, we will briefly introduce some techniques of this method which is our previous research work for dynamic power reduction by comparing some RTL low power techniques. x Next, load-enable based clock gating which works with an enable signal is introduced. According to the idle mode of some components in our simply hash encryption system, we use this load-enable based clock gating to eliminate wasted toggle rate of some signals, thus reducing dynamic power consumption. Finally, according to the source of dynamic power dissipation, reducing clock frequency is another choice. Frequency trade-off technique is proposed, which combines unrolling transformation with frequency scaling. In this technique, a scope of frequency value is given in each hash function with different number of iteration rounds for trading off low dynamic power consumption and high throughput.
M.S. in Electrical Engineering, May 2013
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Title: REAL TIME STATIC SCENE 3D RECONSTRUCTION USING DEPTH SENSORS FOR AUGMENTED TELEOPERATION
Creator: Srinivasan, Ranga Ramanujam
Date: 2015, 2015-05
Description: In the first part of this Master’s Thesis, literature survey is done to find the best performing algorithm in terms of real-time performance...
Show moreIn the first part of this Master’s Thesis, literature survey is done to find the best performing algorithm in terms of real-time performance and quality of 3D reconstruction from depth images. Kinfu of PCL is found to be the best in terms of real-time performance and maintainability, as it is open-source software, with thousands of users working on to improve it. The primary part of the thesis is to improve on the 3D reconstruction quality of Kinfu and this is achieved by improving on the three important stages of Kinfu, Depth Filtering, Pose-estimation and 3D reconstruction. A new Anisotropic depth filtering kernel is proposed and it is found to give 23% quantitative improvement over baseline Kinfu. A modified pose-estimation which incorporates the uncertainty or error characteristics of the depth measured as part of the ICP algorithm is proposed. This results in a 51% quantitative improvement and a big subjective quality improvement over baseline Kinfu. A similar approach based on depth error characteristics but applied to 3D reconstruction stage which is based on an already published paper [1], is implemented. All the improvements in each of the three stages are combined together, to get a robust, real-time 3D reconstruction framework.
M.S. in Electrical Engineering, May 2015
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Title: Tungsten lamp as a secondary standard of light
Creator: Bremers, H. J., Jr., Chapman, A. J., Jr.
Date: 2009, 1910
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/tungstenlampasse00brem
Thesis (B.S.)--Armour Institute of Technology

Title: ACTION RECOGNITION USING SPATIO-TEMPORAL FEATURE EXTRACTION
Creator: Mesmakhosroshahi, Maral
Date: 2012-04-24, 2012-05
Description: The importance of automatically recognition of human activities and it's ap- plications increase as the technology is growing fast these days....
Show moreThe importance of automatically recognition of human activities and it's ap- plications increase as the technology is growing fast these days. In this thesis we focus on the action recognition techniques using 3D feature extraction techniques and try to improve the performance of the available feature extraction methods to have more accurate action classi cation. This thesis is based on spatio-temporal feature extraction techniques that can be extension of two dimensional feature extractions. At rst, 3D corner detector and 3D blob detector, two popular interest point detectors that successfully extended to spatio-temporal domain are reviewed. 3D corner detector is an extension of Harris corner detector which is proposed for corner detection in space-time and 3D blob detector is the 3D version of Hessian blob detector. A method is proposed to improve the robustness of 3D corner detectors against illumination variances based on the application of sigmoid function in contrast stretching. These interest points need to be described by feature vectors. In this part also a review on the SIFT descriptor and it's 3D extension is done. Another 3D feature descriptor discussed in this thesis is Cuboid. In the feature description part a new method is proposed based on the 3D SIFT feature descriptor by changing the binning method of the gradient orientation histogram to a non-uniform binning scheme. Using these non-uniform bins increases the accuracy of action classi cation by focusing on the areas near the interest points. Action classi cation is done using bag of features and supervised learning techniques. For making a dictionary of features, feature vectors are clustered by K-means clustering method and support vector machine is used for classi cation of human activities.
M.S. in Electrical Engineering, May 2012
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Title: Study of phasing transformers
Creator: Meyer, E. D.
Date: 2009, 1906
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/studyofphasingtr00meye
Thesis (B.S.)--Armour Institute of Technology

Title: NEURAL ADAPTIVE CONTROL STRATEGY FOR HYBRID ELECTRIC VEHICLES WITH PARALLEL POWERTRAIN
Creator: Gurkaynak, Yusuf
Date: 2011-04-20, 2011-05
Description: In a hybrid electric vehicle (HEV) with parallel powertrain, the system can be controlled by splitting the required power between the electric...
Show moreIn a hybrid electric vehicle (HEV) with parallel powertrain, the system can be controlled by splitting the required power between the electric propulsion machine and internal combustion engine (ICE) to meet specific goals related to fuel consumption, efficiency, performance, and/or emissions. This power splitting scenario, which is of great hybridization importance, is in fact the control strategy or energy management of the hybrid vehicle. Performance of the system depends on the control strategy, which needs to be robust, stable, reliable, and independent from uncertainties. This Ph.D. research is focused on model based control strategies, which are proposed for parallel hybrid powertrains, showing significant advantages in performance and fuel economy. If a model based control strategy is used to develop the hybrid power management algorithm, the accuracy of the model data needs to be high for proper control. Therefore, this type of management method is parameter sensitive. Implementing system identification features into this algorithm reduces the effect. As a result, the proposed controller algorithm learns the existing component parameters while operating. Furthermore, combining the base controller with an online tuner, which simultaneously optimizes the controller for current conditions, will improve the performance of the power management. In addition, this Ph.D. thesis presents a novel neural adaptive equivalent consumption minimization strategy (ECMS) and applies it to a hybrid representative sport utility vehicle (SUV) with parallel powertrain. The ECMS is a model based optimal control strategy and is based on the minimization of both fuel consumption and battery charge usage by introducing the equivalent coefficient between them. Proper operation of the controller depends on the accuracy of the model. It also depends on the correct selection of the equivalent coefficient. In this Ph.D. thesis, specific neural network structures are proposed for both coefficient selections by drive cycle recognition and for precise model building by system identification. This thesis also presents a novel fast solution method of ECMS algorithm for real time applications.
Ph.D. in Electrical Engineering, May 2011
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Title: NETWORK CODING BASED COOPERATIVE PEER-TO-PEER REPAIR IN WIRELESS NETWORKS
Creator: Liu, Yu
Date: 2012-07-11, 2012-07
Description: Multimedia Broadcast/Multicast Service (MBMS) in cellular networks has emerged recently as a promising distribution model to provide rich...
Show moreMultimedia Broadcast/Multicast Service (MBMS) in cellular networks has emerged recently as a promising distribution model to provide rich content distribution where a batch of content is broadcast to a large number of peers simultaneously. However, ensuring efficient error-free message delivery in such a scenario is a challenge, since packet loss is inevitable due to the time-varying nature of wireless transmissions, and the server is probably overwhelmed by floods of individual retransmission requests from peers. Cooperative Peer-to-Peer (P2P) information repair has been proposed to mitigate the packet loss among peers during Base Station (BS) broadcast, by allowing peers to cooperate on information exchange among themselves, rather than asking the BS to rebroadcast the lost packets for the peers. Network Coding, a fairly recent transmission paradigm with the potential network throughput improvement and high reliability advantage, has been widely recognized as a promising information dissemination approach for wireless networks. In this research, we study the network coding based cooperative P2P information repair in wireless networks. We first propose our initial work - a connected dominating set (CDS) based P2P information repair (PPIR) protocol with network coding which utilize the clustering idea, to minimize the total repair latency as well as alleviate the congestion and burden of BS’s downlink channels. Then the decision making problem for P2P repair with densely distributed nodes is studied and two approaches are provided. Later on, the NC based P2P information repair protocol with tunable parameter (NC-PIRTP) which evolved from PPIR protocol is proposed to further reduce transmission collisions and total repair latency. At last, P2P information repair under mobile network environment with pedestrian speed is studied and three efficient protocols are illustrated which are suitable to different specific cases. Extensive simulation results are provided for performance evaluation and comparisons, and to demonstrate the effectiveness and efficiency of our proposed protocols in terms of the total repair latency. Furthermore, an analytical model is developed, based on which theoretical results are derived. These results validate our protocol models and provide useful protocol design guideline for the cooperative P2P information repair problem in wireless networks.
Ph.D. in Electrical Engineering, July 2012
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Title: POWER SYSTEM VOLTAGE STABILITY AND AGENT BASED DISTRIBUTION AUTOMATION IN SMART GRID
Creator: Nguyen, Cuong Phuc
Date: 2011-04-25, 2011-05
Description: Our interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The...
Show moreOur interconnected electric power system is presently facing many challenges that it was not originally designed and engineered to handle. The increased interarea power transfers, aging infrastructure, and old technologies, have caused many problems including voltage instability, widespread blackouts, slow control response, among others. These problems have created an urgent need to transform the present electric power system to a highly stable, reliable, efficient, and self-healing electric power system of the future, which has been termed “smart grid”. This dissertation begins with a discussion on the voltage stability issue in bulk transmission networks. A new continuation power flow tool for studying the impacts of generator merit order based dispatch on inter-area transfer capability and static voltage stability is presented. In using this tool, it is realized that all distribution systems are represented by only a single lumped load model. While this representation is acceptable in traditional power system analysis, it may not be valid in the future smart grid where the distribution system will be integrated with intelligent and quick control capabilities to mitigate voltage problems before they propagate into the entire system. Therefore before analyzing the operation of the whole smart grid, it is important to understand the distribution system first. The second part of this dissertation presents a new platform for studying and testing emerging technologies in advanced Distribution Automation (DA) within smart grids. Due to the key benefits over the traditional centralized approach, namely flexible deployment, scalability, and avoidance of single-point-of-failure, a new distributed approach is employed to design and develop all elements of the platform. The multi-agent system (MAS), which has the three key characteristics of autonomy, local view, and decentralization, is selected to implement the advanced DA functions. The intelligent agents utilize the communication network for cooperation and negotiation. Communication latency is modeled using a user-defined probability density function. Failure-tolerant communication strategies are developed for agent communications. Major elements of advanced DA are developed in a completely distributed way and successfully tested for several IEEE standard systems, including: Fault Detection, Location, Isolation, and Service Restoration (FLISR); Coordination of Distributed Energy Storage Systems (DES); Distributed Power Flow (DPF); Volt-VAR Control (VVC); and Loss Reduction (LR).
Ph.D. in Electrical Engineering, May 2011
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Title: MANAGING STOCHASTIC WIND POWER GENERATION BY INCORPORATING DEMAND RESPONSE IN DAY-AHEAD SCHEDULING
Creator: Al Hassan, Hassan
Date: 2015, 2015-05
Description: This thesis proposes a stochastic algorithm for managing the variability of wind energy by incorporating hourly demand response in the day...
Show moreThis thesis proposes a stochastic algorithm for managing the variability of wind energy by incorporating hourly demand response in the day-ahead scheduling in power systems. Monte Carlo simulation with Latin hypercube sampling technique is applied to represent the uncertainties of wind energy via different wind scenarios. Demand response has several physical and operating constraints to be considered into the stochastic security-constrained unit commitment (SCUC) for economic, reliability, and security purposes. Benders decomposition method is applied to decompose the large-scale complex stochastic SCUC problem into several tractable problems. Different case studies are analyzed in this thesis to demonstrate the benefits of applying DR to the proposed day-ahead scheduling model with variable wind energy.
M.S. in Electrical Engineering, May 2015
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Title: VIEW SYNTHESIS OF THREE DIMENSIONAL VIDEOS USING VIDEO PLUS DEPTH
Creator: Loghman, Maziar
Date: 2012-07-02, 2012-05
Description: This thesis investigates the use of segmentation in view synthesis for three- dimensional video. View synthesis is the process of generating...
Show moreThis thesis investigates the use of segmentation in view synthesis for three- dimensional video. View synthesis is the process of generating novel views of a scene, using set of views as the reference. Recently, several techniques have been suggested that use the depth maps for rendering virtual views. However, inaccuracy in depth maps causes annoying visual artifacts in depth-based view synthesis. This thesis presents an e cient depth image-based rendering technique based on segmentation using multi-level thresholding. In the proposed algorithm, rst all the images are segmented according to the depth and the pixels belonging to di erent objects are warped and blended independently. Based on multi-level thresholding, an algorithm for nding the ghost contour pixels is provided which simpli es the computations. A novel method for inpainting for disocclusions is introduced which uses the segmented images to nd the associated background boundary pixels. The experimental results show that the proposed algorithm improves the PSNR of the synthesized views up to 0:68 dB for the multi-view video test sequences and eliminates the annoying artifacts.
M.S. in Electrical Engineering, May 2012
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Title: VIBRATION IN TRACTION MOTORS FOR ELECTRIC AND HYBRID ELECTRIC VEHICLES
Creator: Yang, Zhi
Date: 2014, 2014-12
Description: Due to increased fuel efficiency and lower cost/mile feature, electric vehicle (EV) and hybrid electric vehicle (HEV) are becoming more and...
Show moreDue to increased fuel efficiency and lower cost/mile feature, electric vehicle (EV) and hybrid electric vehicle (HEV) are becoming more and more popular. It is estimated that the sale of electric vehicles will reach 3.8 million by 2020, while hybrid vehicles will grow to 4% by 2020 from their current share of 2%. To meet this target, EV an HEV motors, the core energy conversion components, should not only satisfy specific requirements in performance and efficiency but also constrain vibration. This necessitates the analysis of vibration in traction motors for EV/HEV application. The primary objective of this dissertation is to characterize and compare the electromagnetic and vibrational behavior of typical traction motors (PMSM with distributed winding, PMSM with concentrated winding, IM, and SRM) over a wide torque speed range. For this purpose, weak-coupled analysis of electromagnetic force and structure are performed in ANSYS environment. The secondary aim of this dissertation is to develop a rotor position related variable switching frequency pulse width modulated (PWM) strategy to ameliorate the acoustic noise due to high frequency harmonic current. Switching frequency is modified online to adapt current ripple and vibration requirement, thus ameliorate the acoustic noise. It is expected that this strategy with variable switching frequency has the advantages of spreading the vibration spectrum and reducing switching losses. Experimentally verification is also performed. At the end of this dissertation, characterization of vibration behavior of switch reluctance machine with higher number of rotor poles than stator poles is performed.
Ph.D. in Electrical and Computer Engineering, December 2014
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Title: A study of the alternating current series motor
Creator: Peters, Williams H., Petty, Edwin W
Date: 2009, 1909
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/studyofalternati00pete
Thesis (B.S.)--Armour Institute of Technology

Title: Study of the starting torque in a polyphase synchronous motor
Creator: Marshall, H. B., Wright, M. E.
Date: 2009, 1905
Publisher: Armour Institute of Technology
Description: http://www.archive.org/details/studyofstartingt00mars
Thesis (B.S.)--Armour Institute of Technology

Title: CMOS POLAR DIGITAL POWER AMPLIFIER FOR HIGH DATA RATE WIRELESS COMMUNICATIONS
Creator: Zhu, Qiuyao
Date: 2016, 2016-12
Description: Power amplifier (PA) is the most important circuit block in an RF transmitter. It typically consumes more than 80% of the power taken by the...
Show morePower amplifier (PA) is the most important circuit block in an RF transmitter. It typically consumes more than 80% of the power taken by the entire transmitter. Therefore, a highly efficient PA is the key to a successful RF front-end system. The polar transmitter architecture is studied herein in order to take advantage of the highly efficient switching-mode PA. However, due to the large expanded bandwidth from the nonlinear IQ to polar conversion and the sensitive amplitude/phase delay impairment, hardly any reported polar design is able to transmit high data rate wireless communication signals. In this work, an extensive research on the digital polar transmitter system for high data rate signals is presented. An integrated CMOS digital power am- plifier (DPA) design is demonstrated afterwards. This DPA consists of 9-bit fully thermometer-coded uniform cells to achieve high linearity for wide bandwidth OFDM signals. By analyzing the amplitude and phase paths impairment, which will cause both in-band and out-of-band distortions, a 960 MHz digital delay tuner is designed for precise amplitude and phase alignment. Furthermore, two digital pre-distortion algorithms for DPA are implemented and compared. Importantly, an on-chip DC- DC converter is included for direct battery connection and power control. A boosted cascode gate bias improves PA efficiency at the low power region. The proposed design is fabricated using a 55 nm RF CMOS technology. The DPA with several peripheral blocks occupies only 0.63 mm2 active silicon area. This DPA including the digital AM filtering achieves a peak output power of +21.9 dBm with 41% efficiency. It achieves EVM of 2.9% with 20 MHz IEEE 802.11ac compliance of 256-QAM OFDM signals, and also achieves EVM of 4.5% (CC0) / 4.8% (CC1) with 2 x 20 MHz 3GPP LTE-Advanced carrier aggregation compliance of 64-QAM OFDM signals. This highly linear DPA has demonstrated high flexibility, high efficiency, and small area. To the author's knowledge, this is the first reported DPA that meets either the linearity requirements of 256-QAM OFDM signals or the signal bandwidth of 40 MHz, paving the path for wideband high data rate wireless applications using digital polar architecture. At the same time, aiming at a higher average efficiency, a two-level class- G supply modulator is investigated to dynamically switch the DPA VDD. It has successfully demonstrated an average efficiency of 34.6% for this class-G modulated DPA in a complete circuit simulation using the IEEE 802.11b signal.
Ph.D. in Electrical Engineering, December 2016
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