Northern Canada AP/MTT Jt. Chapter

June 10th, 2017


The IEEE Northern Canada Section Antennas and Propagation Society and the Microwave Theory and Techniques Society Joint Chapter (IEEE NCS AP-S/MTT-S) is pleased to announce another Distinguished Lecturer seminar. Professor Karu Esselle, Electronic Engineering, Macquarie University, Sydney, Director of WiMed Research Centre, will be giving a presentation titled “Many names, many advantages – Are resonant cavity antennas the killer planar space-saving approach to get 15-25 dBi gain?“.


ICE 7-395, University of Alberta


26-June-2017 12:00PM to 01:00PM


No other antenna concept has more names. At present these antennas are known as Fabry-Perot cavity resonator antennas, Partial Reflector Surface (PRS) based antennas, Electromagnetic Band Gap (EBG) Resonator antennas (ERAs) and Two-Dimensional Leaky-Wave Antennas, and more names are forthcoming. Yet they all have more or less the same configuration consisting of a resonant cavity, formed between a partially reflecting superstructure and a fully reflecting (ground) plane. The resonant cavity is excited by a small feed antenna. Hence, they are referred to as resonant cavity antennas (RCAs) in this presentation. Since the concept of using a “partially reflecting sheet array” superstructure to significantly enhance the directivity was disclosed by Trentini in 1956, it has been an attractive concept to several antenna researchers for several reasons, including its theoretical elegance, relationships to other well-researched area such as leaky-waves, EBG, frequency selective surfaces and metasurfaces, and practical advantages as a low-cost simple way to achieve high-gain (15-25 dBi) from an efficient planar antenna without an array, which requires a feed network. The RCA concept is one of the main beneficiaries of the surge of research on electromagnetic periodic structures in the last decade, first inspired by EBG and then to some extent by metamaterials. As a result, RCAs gained a tremendous improvement in performance in the last 10 years, in addition to other advantages such as size reduction. As an example, achieving 10% gain bandwidth from such an antenna with a PSS was a major breakthrough in 2006 but now there are prototypes with gain bandwidths greater than 50%. Until recently most RCAs required an area in the range of 25-100 square wavelengths but the latest extremely wideband RCAs are very compact, requiring only 1.5-2 square wavelengths at the lowest operating frequency. Once limited to a select group of researchers, these advantages have attracted many new researchers to RCA research domain, and the list is growing fast, as demonstrated by the diversity of authors in recent RCA publications. RCAs have already replaced other types of antennas, for example as feeds for reflectors. Have they become the killer planar alternative to 3D antennas such as horns and small reflectors? If not, what needs to be done to reach that stage?
This presentation will take the audience through historical achievements of RCA technology, giving emphasis to breakthroughs in the last 10 years. Special attention is given to methods that led to aforementioned bandwidth enhancement and area reduction, dramatic improvement of gain-bandwidth product and unprecedented gain-bandwidth product per unit area demonstrated by RCAs, both theoretically and experimentally. Several choices of superstructures are discussed. These superstructures include all dielectric superstrates with axial permittivity gradients and transverse permittivity gradients and printed superstructures also known as PSSs or metasurfaces. Due to ultra-compactness of modern designs and edge radiation becoming a significant player in the principle of operation, different optimisation methods and strategies have been developed to replace previous unit-cell based methods, which were only suitable for previous larger RCAs. In particular, optimisation of RCAs using automated optimisation methods, including evolutionary algorithms such as Genetic algorithms and Particle Swarm algorithms as well as statistical optimisation algorithms, is described, illustrating the improvements that have been achieved from such optimisations by the speaker’s team and others. Near-filed phase transformation with metasurface-like phase correction structures (PCS) to enhance near-field phase uniformity, and hence far-field directivity, of conventional larger RCAs is presented, highlighting physical reasons for the phase non-uniformity. Both printed (metasurface-type) PCSs and all-dielectric PCSs are included in this discussion. The presentation will conclude with yet unresolved issues, which could be addressed in future research.


Professor Karu Esselle, IEEE ‘M (1992), SM (1996), F (2016), received BSc degree in electronic and telecommunication engineering with First Class Honours from the University of Moratuwa, Sri Lanka, and MASc and PhD degrees in electrical engineering from the University of Ottawa, Canada. He is a Professor of Electronic Engineering, Macquarie University, Sydney, Director of WiMed Research Centre (one of the two) and the Past Associate Dean – Higher Degree Research (HDR) of the Division of Information and Communication Sciences. He has also served as a member of the Dean’s Advisory Council and the Division Executive from 2003 to 2008 and as the Head of the Department several times. He is also the chair of the Board of management of Australian Antenna Measurement Facility, and elected Chair of both IEEE New South Wales (NSW) Section, and IEEE NSW AP/MTT Chapter, in 2016 and 2017. He directs the Centre for Collaboration in Electromagnetic and Antenna Engineering, and has been selected as one of the three new Distinguished Lecturers of IEEE AP Society for 2017-2020. He is the first Australian AP Distinguished Lecturer (DL) in almost two decades, and the second Australian AP DL ever. When Professor Esselle was elected to the IEEE Antennas and Propagation Society Administrative Committee for a three year term in 2014, he became the only person residing in the Asia-Pacific (IEEE Region 10) to be elected to this highly competitive position in a period of at least six years (2010-2015). He was elevated to IEEE Fellow grade for his contributions to resonance-based antennas. He is also a Fellow of Engineers Australia.

Professor Esselle has authored almost 500 research publications and his papers have been cited over 4,000 times. He is the first Australian antenna researcher ever to reach Google Scholar h-index of 30 and his current h-index is the highest among Australian antenna researchers when Google Scholar errors are corrected. Since 2002, his research team has been involved with research grants, contracts and PhD scholarships worth over 15 million dollars. Professor Esselle has been invited to serve as an international expert/ research grant assessor by several nationwide research funding bodies overseas. He has been invited by Australian and overseas universities to assess applications for promotion to professorial levels. Thirty six international experts who examined the theses of his recent PhD graduates ranked them in the top 5% or 10%. Professor Esselle has provided expert assistance to more than a dozen companies including Intel, Hewlett Packard Laboratory (USA) and Cisco Systems (USA). He is an Associate Editor of IEEE Transactions on Antennas and Propagation and IEEE Access. His research activities are posted in the web at .

May 2nd, 2017

The IEEE Northern Canada Section Antennas and Propagation Society and the Microwave Theory and Techniques Society Joint Chapter (IEEE NCS AP-S/MTT-S) is pleased to announce another Distinguished Lecturer seminar. Dr. Walid Ali-Ahmad, VP of Technology at Qualcomm, Inc. will be giving a presentation titled “Advanced RF Front-End and Transceiver Systems Design Overview for Carrier Aggregation based 4G/5G Radios “.


ICE 7-395, University of Alberta


15-May-2017 11:00AM to 12:30PM


Over the past few years, there has been an explosion in the mobile data usage mostly due to the increasing number of tablets and smartphones in use. To support such demand, wider transmission bandwidths are needed, and hence, the technique of Carrier Aggregation (CA) has been introduced in 4G cellular systems. This enables scalable bandwidth expansion beyond the single LTE carrier by aggregating two or more LTE component carriers of similar or different baseband bandwidth, which can be chosen from the same 3GPP frequency band (intra-band) or different 3GPP frequency bands (inter-band). Furthermore, CA is supported by both FDD and TDD modes, and this offers the optimum flexibility in the way the spectrum is utilized and how the network scheduling is configured. In order to push towards 5G data rates (>1Gbps), leveraging more antennas and transmitting more bits per symbol to increase spectral efficiency requires the use of MIMO and higher-order modulation techniques. This presentation focuses on discussing the RF system architectural challenges for Advanced-LTE based user equipment (UE) radio, and the resultant increased complexity in the radio due to the use of CA, MIMO, and higher order modulation techniques; furthermore, concurrency and coexistence scenarios with other radio access technologies (RAT) are considered in how they further add to the complexity of the RF front-end and to its linearity requirements.


Walid Ali-Ahmad is currently a VP of Technology at Qualcomm, Inc; he is involved in the architecture and RF systems design of advanced RF front-ends and transceiver systems for 4G and 5G User Equipment (UE). Before July 2014, he was a senior director of Technology at Mediatek, and led the architecture and RF systems design of low-cost 2G/3G/LTE integrated transceivers and SoCs for China market feature phones and smartphones. He was a visiting professor in the ECE department at UC San Diego during Winter term 2016, and was an associate professor in the Electrical Engineering department at the American University of Beirut between Sept 2004 and Sept 2007, with a focus on applied electromagnetics and communication circuits and systems. Between July 1997 and July 2004, he was a principal member of Technical staff at Maxim Integrated products, and led the systems development of the first low-cost low-power WCDMA direct-conversion transceiver IC in SiGe BiCMOS. He holds several patents in the area of RF front-end tuning, and has published many articles and given many talks in the area of RF systems design for cellular and millimeter-wave radio systems. He is a senior IEEE member, and has been part of the IEEE RFIC conference steering committee since 2012; he is currently the RFIC’2017 TPC chair.

May 1st, 2017

Thanks to all of our presenters who helped to make these student seminars a success. All of the presenters were ranked by our audiences, all of which were awarded cash prizes. After tallying the audience’s ratings, we are pleased to announce the rankings:

First Place:

Cameron Hough, “Biological dosimetry of THz radiation for potential biomedical application”


Second Place:

Elham Baladi, “Devices and Methods Using Apertures Lined with Thin ENNZ Metamaterial Liners”


Third Place:

David Sawyer, “Choke Ring Structures for Ground Penetrating Radar”

Our thanks also go out to all of our volunteers for organizing these events and helping to make them a success. Please watch our website for updates on next events!

April 24th, 2017

The IEEE Northern Canada Section Antennas & Propagation Society and the Microwave Theory & Techniques Society (IEEE NCS APS/MTTS) joint chapter would like to invite you to attend the next installment of our invited talks.  Professor Lotfollah Shafai from the University of Manitoba will be giving a presentation titled “Challenges of Antenna Miniaturization“.


ICE 8-207, University of Alberta


01-May-2017 01:00PM to 2:00PM


Wireless communication is becoming an essential part of almost all new technologies, especially in personal communication, remote sensing, autonomous navigation, medical imaging and structural or personal health monitoring, to name a few. Since the dominant means of information exchange is electromagnetic waves, they need antennas to transmit and receive the waves and electronics to process them. However, antennas must interface two separate bounded and unbounded media, where waves have distinct and different sizes. Consequently, to interact efficiently with waves their dimensions have become wavelength dependent, limiting their size reductions. This is the major impediment for antenna miniaturization. On the other hand, advancement of traditional technologies and emergence of new ones require ongoing size reductions to incorporate more features and operate at lower cost. This size discrepancy, thus, has made antennas the “Achilles’ heel” of technology progress, and is not limited to any particular area. Any small reduction in the antenna size, without deteriorating their performance, will provide a major progress in related technologies. This presentation will address planar antennas, and highlight the penalties paid for their miniaturization using traditional design methods, and provide examples of new design techniques that can overcome them.


Lotfollah Shafai B.Sc. from University of Tehran in 1963 and M.Sc. and Ph.D., from University of Toronto, in 1966 and 1969. In November 1969, he joined the Department of Electrical and Computer Engineering, University of Manitoba as a Lecturer, Assistant Professor 1970, Associate Professor 1973, Professor 1979, and Distinguished Professor 2002, and Distinguished Professor Emeritus 2016. His assistance to industry was instrumental in establishing an Industrial Research Chair in Applied Electromagnetics at the University of Manitoba in 1989, which he held until July 1994.
In 1986, he established the symposium on Antenna Technology and Applied Electromagnetics, ANTEM, at the University of Manitoba, which has grown to be the premier Canadian conference in Antenna technology and related topics.
He has been the recipient of numerous awards. In 1978, his contribution to the design of the first miniaturized satellite terminal for the Hermes satellite was selected as the Meritorious Industrial Design. In 1984, he received the Professional Engineers Merit Award and in 1985, “The Thinker” Award from Canadian Patents and Development Corporation. From the University of Manitoba, he received the “Research Awards” in 1983, 1987, and 1989, the Outreach Award in 1987 and the Sigma Xi Senior Scientist Award in 1989. In 1990 he received the Maxwell Premium Award from IEE (London) and in 1993 and 1994 the Distinguished Achievement Awards from Corporate Higher Education Forum. In 1998 he received the Winnipeg RH Institute Foundation Medal for Excellence in Research. In 1999 and 2000 he received the University of Manitoba Research Award. He is a life Fellow of IEEE and a life Fellow of The Royal Society of Canada. He was a recipient of the IEEE Third Millenium Medal in 2000 and in 2002 was elected a Fellow of The Canadian Academy of Engineering. In 2003 he received the IEEE Canada “Reginald A. Fessenden Medal” for “Outstanding Contributions to Telecommunications and Satellite Communications”, and a Natural Sciences and Engineering Research Council (NSERC) Synergy Award for “Development of Advanced Satellite and Wireless Antennas”. He held a Canada Research Chair in Applied Electromagnetics from 2001 to 2015, and was the International Chair of Commission B of the International Union of Radio Science (URSI) for 2005-2008. In 2009 he was elected a Fellow of the Engineering Institute of Canada, and was the recipient of IEEE Chen-To-Tai Distinguished Educator Award. In 2011 he received the Killam Prize in Engineering from The Canada Council, for his “outstanding Canadian career achievements in engineering, and his research on antennas”. In 2013 he received The “John Kraus antenna Award” from IEEE Antennas and Propagation Society “For contributions to the design and understanding of small high efficiency feeds and terminals, wideband planar antennas, low loss conductors, and virtual array antennas”. In 3014 he was the recipient of Edward E. Altshuler Best paper Prize from IEEE APS Magazine. His students have received numerous Best paper awards from IEEE, and young scientist awards from URSI.

March 23rd, 2017

We are pleased to announce the first session in our student seminar series 2017. Two of our students will be presenting on  WednesdayMarch 29 from 12:00 pm – 1:00 pm in ICE 8-207. 

Speaker #1: David Sawyer – “Choke Ring Structures for Ground Penetrating Radar

Background: Ground penetrating radar (GPR) is a mature and successful technology that replaces expensive excavation and prospecting with simple scanning and imaging. Due to the high degree of loss in the ground at microwave frequencies, GPR systems are extremely susceptible stray reflections and interference (known as clutter), which can overwhelm signals of interest. For common GPR antennas such as dipoles, shielding, such as with a metallic cavity, is an attractive way to isolate the antenna from the above-ground environment. However, currents induced on the shield by the antenna can travel around the shield and re-radiate, acting as a source of clutter and offsetting these benefits. Choke rings are a well-known structure used for global positioning systems that reduce multi-path interference that work by suppressing currents along a plane. This work presents choke-ring structures as a way to suppress these currents for GPR and demonstrates that good bandwidth and time-domain performance may be achieved through the use of resistive, rather than perfectly metallic structures.

Biography: David Sawyer graduated from the University of Alberta with a B.Sc. in engineering physics in 2015, and as of 2017 is currently in the process of his M.Sc. in the area of microwave circuits. His current work is involved in the areas of metamaterial surfaces, small antennas, and ground penetrating radar, considering both frequency and time domain results. His work in this area has recently been accepted for publication at the AP-S Symposium on Antennas and Propagation. Some of David’s interests include fundamental limitations in electromagnetics, as well as numerical and mathematical methods in electromagnetics. David’s interests also extend to the arts. He currently helps run the University of Alberta Mixed Chorus as part of their executive, and is also a member of a local dance performance team.

Speaker #2: Mitchell Semple – “Optical Implementation of a Miniaturized ENNZ-Metamaterial-Lined Aperture Array


Abstract: Aperture arrays have been used as frequency selective surfaces and to demonstrate extraordinary transmission, and have been proposed for a multitude of applications. The operation of these devices requires large areas as they depend on either aperture size or array periodicity, respectively, on the order of a wavelength. It has recently been demonstrated that lining each circular aperture in an array with a thin epsilon-negative and near-zero (ENNZ) metamaterial dramatically lowers its resonance frequency while the aperture itself remains largely empty, obviating the need for both large apertures and large aperture spacing. Thus, aperture-array-based devices could be miniaturized in the microwave regime (E. Baladi, J. G. Pollock, and A. K. Iyer, Opt. Express, vol. 23, no. 16, 2015).
An optical implementation of the ENNZ-metamaterial-lined aperture array, simulated using COMSOL Multiphysics, will be presented. Challenges in achieving an optical implementation included the reliance of the microwave design on lumped circuit elements and near-ideal conductor properties, which cannot be reproduced directly at optical frequencies. The proposed optical aperture array was designed to improve transmission at optical-telecommunications wavelengths of λ = 1.55 μm (f = 193 THz) through apertures of size λ/5 and spacing λ/4. For a patterned gold surface with minimum feature size of 10 nm, an 8.7 dB transmission improvement over the unlined case was realized.

Biography: Mitchell graduated from the University of Alberta in 2016 with a B.Sc. in Electrical Engineering. He has previously worked on integrating molecular junctions into guitar distortion pedals as amplifier feedback elements and is currently an M.Sc. student working on plasmonic metamaterials.

Free pizza and refreshments will be served.

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