Statement of Purpose for university application

1. Purposes and Background

My goal for applying to graduate school is that I want to create novel integrated circuits. When I first attended the professor Razavi short course in National Taiwan University (NTU), I was motivated. Professor Razavi gave me an unforgettable insight of the analog circuits. He comments that every detail is pretty important in analog circuits and he encouraged me to create innovative circuits by myself.

My decision to pursue graduation study in the United State is that I wanted to broaden my knowledge. After I graduated form NTU with my master’s degree in electronic engineering, I felt that my knowledge and experience about analog circuit design were not enough. I was an ambitious person and I wanted to be the best person in the field of analog circuit design. Therefore, I made up my mind to pursue the doctor of philosophy.

During my graduate studies at the Electrons department of NTU, I designed different types of analog integrated circuit such as phase locked loops, clock and data recovery circuit and analog to digital converter. These topics enrich my knowledge of analog integrated circuit and enable me to in-depth analyze and implement the circuit. My enduring studying arose from my interest of the high-speed analog integrated circuits. I regarded the high-speed analog integrated circuits as a work of art. With the intense conscious on the research, I finally acquired sufficient measurement results and presented my research on the Asia Solid State Circuits Conference (ASSCC). In addition, I also had cooperated with my colleague and we published our research on International Solid State Circuits Conference (ISSCC) and Journal of Solid State Circuits (JSSC). Furthermore, I also learned how to balance between research and life, and I finally found my interest I could dedicate myself future and career to.

2. Personal characteristic

When I pursued my master’s program at NTU, of course, I faced a lot of barrier such as how to solve the bottleneck of the circuits. Whenever I face these barriers, I always be positive and patient to solve them. For example, when I was designing the 60Gb/s transmitter with my colleague, we faced the problem that our circuit could not operate at such high speed because of the limited process. However, we worked cooperatively and orderly in order to think of the solution. Finally, we used the architecture of distributing amplifier and solved the problems.

I am always open-minded and congenial even if I face the barrier. In my views, the barrier hones my skill and irrigates my mentality, improving me to be a better person. I love the phrase by Sir Winston Leonard Spencer Churchill: Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning. This phrase always encourages and motivates me to be positive whenever I face barriers.

3. Research Experience and Academic Projects

When I was in the electronic engineering master’s program at NTU, I focused on the high-speed analog integrated circuits design. I participated in Professor Jri Lee’s laboratory for two years and Professor Tai-Cheng Lee’s laboratory for a year.

After accumulated research experience and training in lab, now I am a skillful high-speed integrated circuits engineer. I have abundant experience about design of analog integrated circuits such as phase locked loop (PLL) circuits, clock and data recovery (CDR) circuits, and analog to digital converter (ADC).

(1)PLL phase noise modeling and analyze using Matlab:
During my first year in the master’s program, I concentrated on how to analyze the phase noise of PLL circuit and used Matlab to analyze the phase noise performance in order to optimize the phase noise performance. I finished the code and compared different PLL architecture phase noise performance such as subsample PLL circuit and mixer-based phase detector PLL circuit.

(2)Implemented a 25Gb/s transmitter with 45nm TSMC Technology:
Besides, I started to handle 25Gb/s transmitter with 45nm TSMC technology project. National Science Council assigned this project to us. This project trained me the ability of working alone. I became more adept at the high-speed analog circuit and self-motivated during the project. The project broaden my knowledge of high-speed wired communication analog circuits.

(3)A 60Gb/s transmitter with TSMC 65nm:
During my second year in the master’s program, I changed to Prof. Jri Lee’ laboratory because I wanted to challenge myself and improved my ability to designed different circuits in a short period. I designed the 60Gb/s transmitter with the colleague of mine. We used the distributed amplifier architecture to accomplish the 60Gb/s multiplexer. I learned the character of distributed multiplexer and how to optimize the distributed multiplexer between the power and stage from this project. Finally, this project had published papers in ISSCC.

(4)GUI Design for a PRBS generator/BERT Prototype Board:
When I was research assistant in the professor Jri Lee’s laboratory, I developed Graphical User Interface (GUI) to control our pseudo-random bit sequence (PRBS) generator and bit error rate tester (BERT) prototype board. I used Labview to develop the GUI and wrote C code to bridge the interface between microcontroller and our PRBS generator and BERT. Developing GUI gives me invaluable experience about firmware knowledge and improves my code ability.

4. Master Thesis

My master thesis consists of three works for different purpose. The first work was the PRBS generator and BERT. I studied these circuits because the demand for inexpensive testing equipment and self-testing circuit on chip. In this work, four different PRBS lengths and four channel outputs were included in the PRBS generator. On the other hand, the BERT checked the incoming sequence from the generator and accumulated the number of error bit and calculated the bit error rate simultaneously. This work had fully verified and published on ASSCC.

The second work was about ultra wide band receiver for V-by-One high speed standard. This work was an analog front-end receiver composed by adaptive equalizer and referenceless CDR circuits. Besides, this work has been proven that the function is correct and robust even if the chip is packaged. The receiver achieves broadband operation range from 600Mb/s to 4Gb/s with 200mW power consumption using the standard Complementary Metal-Oxide-Semiconductor (CMOS).

The last one is designing a 24Gb/s receiver for 3Gb/s Serial Digital Interface application. The receiver includes CDR circuit, analog equalizers, de-multiplexer circuits. In this receiver, I proposed a method for voltage controlled oscillator to select the optimal frequency band which is nearest input data frequency without the reference frequency clock signal and I solved the problems that the conventional frequency detector encounters under the large jitter operation.

5. Work Experience

After graduation from NTU, I became research assistant in the professor Jri Lee‘s laboratory and continued to design various integrated circuits because I felt that I should gain some practical experience about working in a research department and, at the same time I gained some first-hand knowledge of what the life of being a research assistant in university. During this time, I made up my mind to continuously pursue the doctor of philosophy and prepared for presentation on ASSCC in the meantime. I love to research and conduct the challenging project.

After I finished my military service. I got an interview opportunity working at Broadcom International LCC. I applied the interview and I became an employee in Broadcom. I learned a lot of practical experience about designing the innovative analog circuits. I love every minute of my work. Especially, I have the opportunity to acquire the cutting edge knowledge and discuss the circuits with my colleagues. Although I enjoy the work, I realize that I am not going to be satisfied with the current work under the direction of others. I decided to pursue the doctor of philosophy and expanded my horizon.

6. Extracurricular Activity

In addition to conducting research, I am interested in different extracurricular activities. I had ever joined the electrical engineer soccer team at National Tsing Hua University (NTHU). Besides, I also joined the science club to taught the student about the various life science and the principle rule of science in the science camp.

7. Research Interests and Future plan

My research interest is to explore the high-speed analog integrated circuits such as PLL circuits, CDR circuits and ADCs. I am fascinated by high-speed integrated circuits and eager to be trained in a Ph.D. program with the topics such as these:

1) PLL circuits:
PLL circuits are incorporated into large-scale integrated circuit now. PLL circuits are one of important circuit in system on chip. The various architectures of PLL circuits could be applied for different specification. However, designing high-speed PLL circuits with reasonable power consumption is still challenge. I believe the challenge isn’t the bottleneck and I believe there exists a lot of new methods waiting me to explore. Further, I have the related design experience with PLL circuits when I pursued my master science degree at NTU. I am confident that I can afford for this topic.

2) CDR circuits:
CDR circuits are used to recover the timing and data information from the incoming data sequence at the receiver in wired communication system. Various type of CDR architecture exists including fully analog, fully digital and hybrid based. Different CDR architectures have their pros and cons. But currently designing high speed CDR circuits with low power consumption is still pretty difficult. In today’s tendency, the data rate of wired communication continue to increase so designing the high speed CDR circuits will meet with today’s tendency. In addition, I have ever designed the CDR circuit for 25Gb/s receiver when I pursued my master degree at NTU. I still want to devote myself to explore different method to design high-speed CDR circuits.

3) ADCs:
High-speed low power ADCs have found extensive usage in various systems, RF, backplane transceivers. Especially in recently, Internet of Thing requires high-speed low power ADCs to communicate with each other. Furthermore, ADCs are the key interface between the analog signal and digital signal. For me, I want to develop my depth and breadth of the ADCs and I had ever design ADC during my undergraduate’s project. I am confident that I can afford for this topic.

My immediate goal is that I want to receive graduate training and increase my ability to formulate interesting and important research questions, to address them in a rigorous way, and to improve mt research ability. My long-term goal is I hope to continuously expand on these researches and develop some innovative system or circuit. I believe that I can make some cutting edge study in the field of analog integrated circuits. I constantly learn the newest concept of analog circuit and read the updated journal article. To know the analog integrated circuit more, I will keep learning until I was too old to read. Furthermore, I hope to interact more people, share them with my novel idea and discuss the analog circuit knowhow with them.

8. Preparation for the program and why I choose the program

I have certain characteristics that make me suitable for this program. My background knowledge is sufficient to solve any problem I will encounter during pursue the doctor of philosophy. Besides, based on my working experience and extracurricular experience, I am excellent at making friend and cooperating with different people. My working experience gives me abundant knowledge about how to precisely design the integrated circuit and where is the tradeoff. My programming skill and mathematics allow me to analyze the problem for more advance study. I always keep me conscious on every detail to find the potential problem and avoid it. The dedicated attitude makes me creative and productive, and I like to be pioneer in any field. To sum up, I think myself can afford this program.