Statement of purpose
It has long been my ambition to pursue a Ph.D. at one of the leading engineering institutions in the world. I have worked extremely hard over the past four years to familiarize myself with relevant theory and practice, and have done research in a wide variety of areas such as integrated circuits, 3D-IC, rectennas for wireless power transfer, and energy harvesting. In addition, I have published two conference papers and submitted one journal paper as well as one conference paper. I have also conducted an independent project to build a hexacopter using wireless charging methodology. Following this extensive preparation, I am now applying to join the Robotics Ph.D. Program at your institution, so as to fulfill my personal aspirations and become a leader in the scientific community. I am confident that, by joining this Ph.D. program, I will be able to realize my full potential as a researcher and make meaningful contributions to society as a whole.
Four papers on wireless power transfer and energy harvesting
I have always enjoyed seeking solutions to everyday problems. For example, when we are out and about and a battery in one of our devices requires a recharge, it is often the case that no electrical socket is available. Therefore, I joined Prof. Shih-Yuan Chen of National Taiwan University (NTU) to work on wireless charging projects and proposed four kinds of rectennas. I enjoyed being the primary contributor to a paper entitled “A 2.45-GHz High-Efficiency Loop-Shaped PIFA Rectenna for Portable Devices and Wireless Sensors,” which was accepted for the 2015 IEEE Antennas and Propagation Society International Symposium (IEEE AP-S Conference). The proposed novel asymmetric loop-shaped planar inverted-F antenna (PIFA) rectenna achieved conversion efficiency of 61.4% with a compact size of 0.066λ0 × 0.28λ0. As the first author, I had the honor of presenting it at the symposium to a group of scholars and experts. Moreover, the proposed rectenna had two resonances, offered harmonic suppression, and was easily tunable. This became the basis for a follow-up study, and I wrote a journal paper entitled “High-Efficiency Dual-Band Loop-Shaped PIFA Rectenna with Compact Size for Portable Devices and Wireless Sensors” and submitted it to IEEE Transactions on Antennas and Propagation. As the first author, I gained a thorough understanding of how to meticulously and comprehensively explain physical phenomena involving electromagnetic theory.
My third paper, entitled “Miniaturized SRRs-Loaded Loop Structure for Enhanced Wireless Power Transmission,” was accepted for the 2014 IEEE International Symposium on Antennas and Propagation. In this project, compact, metamaterial-inspired, broadside-coupled, split-ring resonators were embedded within a small loop fed by a coplanar strip to increase the effective permeability of the near zone of the loop to concentrate the magnetic flux. Moreover, the proposed structure embedded with the inner SRRs exhibited greater efficiency over a considerable frequency range and the PTE was found to improve up to 58% around 13.56MHz. I also was the first author of a fourth paper—entitled “A Compact Size Slot Loop Rectenna for Dual-Band Operation at 2.4- and 5.8-GHz ISM Bands”—which was submitted to the 2016 IEEE AP-S Conference. Traditional multi-band slot loop antennas typically operate at resonances on integral multiples of a guided wavelength. However, the proposed antenna was only 0.096λ0 × 0.096λ0.
Research project for Taiwan’s Industrial Technology Research Institute
Meanwhile, I was also interested in learning about cooperation between academia and industry. I took part in a project aimed at inventing a greenhouse sensor module system for Taiwan’s Industrial Technology Research Institute. Our team built a module using an RFID system, temperature sensor, and microcontroller, and created a mechanism for energy harvesting units. The module system did not rely on cables or batteries, a feature that was fully accounted for by the aforementioned high-efficiency dual-band loop-shaped PIFA rectenna. I also proposed a method to predict rectenna efficiency before trials started. By developing such a predictive system, which had been tested and verified in the aforementioned project “A Compact Size Slot Loop Rectenna for Dual-Band Operation at 2.4- and 5.8-GHz ISM Bands,” we were able to effectively design rectennas.
Independent hexacopter project
More recently, a video by Amazon and presentations by Raffaello D'Andrea about quadcopters caught my attention. Even though there is tremendous market potential for such machines, flight time, i.e., battery life, remains a major hurdle. Therefore, I decided to start an independent project to build a multirotor that can recharge wirelessly via a charging pad without human intervention, allowing for an extended journey of multiple hops. A major issue with quadcopters is safety. If one of the four motors fails, the machine will descend immediately. However, with two extra motors, a hexacopter can be created, enhancing the aircraft’s capabilities and allowing users to attach heavy loads or pesticide sprayers, or affix high-performance CPUs and GPUs as well as two cameras, one of which is a depth camera. Generally, there is a roughly 50cm error for a GPS sensor. Therefore, I have used IR tracking to land the hexacopter precisely on a wireless charging pad, which is often located in a sheltered location that increases the chance of lost GPS signal. I have put an omni-antenna on the charging pad and a rotating high-directivity antenna array with a motor and an Arduino computer on the hexacopter. This is similar to how ships at sea find a lighthouse. Moreover, the hexacopter can calculate its power consumption from the starting point to the charging pad. This means the hexacopter will be able to calculate how much it needs to be charged to be able to travel to the next charging pad. Details of this project, as well as my published and draft papers, can be found on my website (www.Jiunn-Kai-Huang.com). I continue to update this website on a regular basis.
Research project on integrated circuits for digital phase lock loop
I volunteered to work on a project with Prof. Liu in my sophomore year at NTU. In this project, I made a traditional analog phase lock loop into an all-digital field and verified mathematical behavior by Matlab. I also applied HSpice to do a closed-loop simulation to substantiate the entire system by changing Verilog to Verilog-A and combined it with an analog circuit with which I used PAR to combine the digital circuit. Lastly, I leveraged Calibre to verify DRC and LVS and run a post-layout simulation. This project gave me a solid foundation in integrated circuits, and helped me gain invaluable experience in working independently.
Research project on 3D-IC communication
Having learned about integrated circuit procedures, I began contemplating whether it would be possible to transform the aforementioned into a three-dimensional package. I decided to do a project with Prof. Tzong-Lin Wu of NTU. I started by looking into ways of compensating for the loss of through-silicon-via—a key point in 3D-IC communication. I constructed a precise TSV model in Agilent Advanced Design System and ANSYS High Frequency Structure Simulator. I also derived mathematical models of RC and RL equalizers to enhance the performance, comparing it with Matlab. I was able to specifically control how much the equalizer would compensate the |S21| at a certain frequency, and further improve the eye diagram. I also provided a standard operating procedure for both the RC and RL equalizers, from which others could easily create the equalizer with certain parameters.
Extracurricular activities and working experience
At NTU, I joined a number of clubs, including the coffee, electric guitar, and photography clubs. In fact, photography has become one of my main hobbies. I also volunteered to tutor children from rural areas, teaching many students for free. The emotional reward in helping these children was far greater than any monetary reward that could have been offered. Moreover, I served as head of the marketing and design department at the Pan Asia Model United Nations 2013 held at Taipei 101, leading a group of 16 in promoting this event and organizing four days of activities for more than 450 university students from around the world. From October 2014 to October 2015, I fulfilled my alternative military service at the ROC Ministry of Foreign Affairs (MOFA). I worked as a photographer and video consultant for the ROC National Day celebrations, and performed photography-related tasks involving senior officials such as President Ma Ying-jeou and Minister of Foreign Affairs David Y. L. Lin. I also helped MOFA resolve various technology problems pertaining to mobile apps, web design, and network security. Because of my strong work ethic and professionalism, I received a recommendation letter from MOFA Spokesperson Eleanor P. Wang.
Because of my dedication to research, as well as my sense of purpose, my professors at NTU strongly encouraged me to apply to your institution, one of the world’s foremost centers of scientific innovation. I firmly believe that my academic credentials, research achievements, leadership qualities, and creative mindset make me an ideal candidate for your esteemed institution. I am particularly interested in the area of energy harvesting, circuits, applied physics, microsystems, electromagnetics, and nanotechnology. I am also keen to explore other fascinating areas such as embedded control systems and connection science and engineering. I very much hope to become a member of your community and contribute to moving the field of electrical engineering and computer science forward for the benefit of society.