Session 1: Design of Filtering Power Amplifiers
In the radio frequency transmitters, power amplifier (PA) is usually followed by bandpass filter to suppress the intermodulation. Because of the inter-connecting mismatching and loss between PAs and filters, the efficiency of the system is degraded. To solve this problem, filtering power amplifier is proposed and designed. This tutorial speech will give the details of filtering Class AB PA. After that, for the bandwidth enhancement, continuous mode filtering PA with wide bandwidth and dual-band-band filtering PA will be taken into consideration. The designs exhibit good frequency selectivity and high power added efficiency (PAE). More importantly, comparing to the conventional power amplifiers, the proposed designs possesse wide bandwidth of 31.1% with PAE higher than 60% and two passbands with PAE of 70.2% and 69.6%.
Speaker: Dr. Yuan Chun Li, South China University of Technology
Yuan Chun Li received the B.S. degree in electronic engineering from Anhui University, Hefei, China, in 2006, the M.S. degree in electronic engineering from the University of Science and Technology of China, Hefei, in 2009, and the Ph.D. degree in electronic engineering from the City University of Hong Kong, Hong Kong, in2012. From Oct. 2012 to Jun. 2015, she was a Research Fellow with the City University of Hong Kong.
She is currently an Associate Professor with the School of Electronic and Information Engineering, South China University of Technology. Her research interests include RF and microwave passive and active circuits, and monolithic microwave integrated circuits. Recently, she has focused on the co-design of the multifunction devices, including filtering baluns, filtering amplifier and so on.
Session 2: Ultra low Profile antenna design and technologies for Ceiling Mount Distributed Antenna System
Today wireless evolution has had a massive impact on the way we communicate with the rising usage of the data streaming and its demand to stay connected at any location at any time. According to statistics from American Telephone and Telegraph (AT&T), nearly 80 percent of all wireless call originate or terminate inside buildings. To meet the needs of the indoor coverage and the rising demand for capacity, Distributed Antenna System (DAS) has been widely accepted as a promising solution by the industry. In recent years, ultra-low profile antennas for indoor distributed antenna system (DAS) have gained increased popularity due to high expectation of aesthetically pleasing profile when integrated into the ceiling design of the building. This has become a new class of requirement in which stable and highly omnidirectional radiation pattern with vertical polarization has been gradually superseded by quasi-omnidirectional with horizontal polarization and aesthetically attractive characteristics. Although the requirement of the omni-directionality reduced but it may still be a concern if the typical antenna approach may have deep null in the azimuth plane that causes blind spot of the coverage. Other than the radiation pattern concern, the spectrum has been kept adding into the long-term evolution (LTE) frequency range as it progresses towards the next generation. In addition to that some regional authority has put the public safety DAS as additional requirement in the indoor coverage that may include the band such as Very High Frequency (VHF), Ultra High Frequency (UHF) and 800MHz. This poses a greater challenge to cover even wider bandwidth e.g. from 350MHz-6000 MHz to support both cellular and public safety application with a reasonable radiation pattern. To maximize the throughput and capacity of a modern DAS system, low Passive Intermodulation has become a necessary requirement. Unfortunately, PIM levels are difficult to calculate, or measure and thus very little explicit documentation exists on the subject. The tutorial is dedicated to Ultralow Profile antenna design and technologies for Ceiling Mount Distributed Antenna System and describes the main challenges and features as well as example of realization of the antenna design in the industry.
Speaker: Ng Kok Jiunn, Laird Technologies(M) Sdn. Bhd
Ng Kok Jiunn was born in Teluk Intan, Perak, Malaysia in 1977. He received the B.Eng. and M.S. degrees in electrical, electronic and system engineering from the National University of Malaysia, in 2000 and 2004 respectively. He is currently pursuing the Ph.D. degree in National University of Malaysia. From 2004 to 2006, he was a Research Engineer with the Anscom Sdn. Bhd. He has involved in concealment solution and initial setup of the research team for Base-station Antenna. He was RF Engineer with Laird Technology (M) Sdn. Bhd. and Senior RF engineer with Amphenol Antenna Solution (M) Sdn. Bhd in year 2006 and 2007 respectively. He has worked various antennas for wireless router, embedded antenna for portable device such as Laptop, handphone, dongle and etc. Since 2008, he has been with Laird Technologies(M) Sdn. Bhd. He was the leader for the antenna design team until 2013 and currently he is Snr. Staff Engineer for Advance Technology Group in Antenna Division. He holds more than 10 patents in various antenna designs including embedded antennas, MIMO antenna, portable radio antenna, LTE Distributed Antenna System platform, vehicular antenna etc. His research interests include embedded antenna, portable land mobile antenna, MIMO antenna, DAS antenna, array antenna, and Low PIM antenna. He is a member of IEEE.
Session 3: Design Considerations of Passive UHF RFID Tags
Fast growth has been seen in the radio frequency identification (RFID) industry in recent years due to the rapid advancements of semiconductor technology. This has significantly lowered the manufacturing costs of the microchip and it has significantly contributed to the rapid increase of the RFID applications in access control, retailing, asset identification, and transportation. Dipolar antennas are commonly used for designing various UHF tags as they can provide broader spatial coverage for better accessibility. When a dipolar tag is brought closer to metallic surface, however, the image current that is being induced is equal in magnitude but opposite in phase, causing its radiation performances to deteriorate significantly. In this talk, the development trends, design methodologies, and tradeoffs of different types of UHF tag antennas will be discussed. It will be shown that designing a UHF tag requires making tradeoffs between radiation efficiency, impedance bandwidth, and tag size. The market trends will also be analyzed.
Speaker: Prof. Dr. Eng-Hock Lim
Eng-Hock Lim was born in Selangor, Malaysia. He received his B. Sc. (Electrical Engineering) from National Taiwan Ocean University, M. Eng. (Electrical and Electronic Engineering) from Nanyang Technological University, and Ph.D. (Electronic Engineering) from City University of Hong Kong. He served as the Associate Editor of the IEEE Transactions of Antennas and Propagation from 2013 to 2016. Currently, he is a Professor at Universiti Tunku Abdul Rahman, where he is serving as the Chairperson of the Center for Communication Systems and Networks. He is the IEEE Malaysia Distinguished Lecturer for 2019-2020. His current research interests include RFID antenna design, reflectarrays/transmitarrays, and multifunctional antennas.