Mojgan Daneshmand and Pedram Mousavi Memorial Student Seminar Series in Electromagnetics
IEEE NCS AP-S/MTT-S Joint Chapter as a part of the ECE Departmental Seminar Series for March 2021
Date: Wednesday, March 17, 2021, Wednesday, March 24, 2021, Wednesday, March 31, 2021
Time: 3:00 PM Eastern Daylight Time
Duration: 1 hour
To Join: Visit this Link
March 17
Adam Maunder: Metamaterial Liner for Magnetic Resonance Imaging
Abstract: There are a number of challenges to ultra-high field MRI (>4.7T): signal inhomogeneity, increased localized heating and challenging RF coil design with increased tuning complexity/instability. Travelling wave MRI, using the bore of the MRI scanner a waveguide, was developed as potential way to improve the homogeneity of MR signal excitation/reception and reduce the localized heating in the body. However, previous implementations have suffered from low efficiency and it requires a bore size sufficiently large to support propagating waves at the 1H Larmor frequency. A method of reducing the cut-off frequency for propagation with a thin metamaterial liner has been developed at the University of Alberta, permitting efficient MR excitation with the benefits of travelling wave MRI for reducing the cut-off frequency for propagation with a thin metamaterial liner has been developed at the University of Alberta, permitting efficient MR excitation with the benefits of travelling wave MRI for any field strength. This presentation introduces the framework developed to design metamaterial liners for below-cutoff propagation and the preliminary results of designs for whole-body 1H MRI and dual tuned 1H and 23Na head imaging at 4.7T.
Azita Goudarzi: Wideband High-Gain Resonant Cavity Antennas (RCA)
Abstract: Resonant cavity antennas (RCAs) are suitable candidates to achieve high-directivity with a low-cost and easy fabrication process. Since the PRS is a resonant structure, the bandwidth of RCA is narrow. Many investigations have been carried out to enhance the PRS bandwidth. Using a PRS with positive reflection phase gradient is a potential solution to increase the bandwidth of the RCAs. In this presentation, the study directions of the RCAs with the recent investigations and applicable examples are reviewed and followed by proposing a new wideband RCA with circular polarization. The proposed RCA uses a PRS structure whose reflection phase has a positive slope and a novel main radiator to illuminate the PRS layer.
March 24
Nabil Khalid: Battery-less RFID Based Wireless Sensors for 5G IoT
worked at RWR Pvt. Ltd., Islamabad, Pakistan from 2013 to 2014 as a design engineer in the RF/Microwave department. His focus was on designing industrial-grade power amplifiers. From 2015 to 2017, Nabil worked at Next-generation and Wireless Communications Laboratory (NWCL) as a research assistant, and being a TUBITAK scholar, he received his Master of Science in Electrical and Computer Engineering from Koc University, Istanbul, Turkey. His focus was on developing the physical layer of THz Band wireless communications. Following that, he joined Intelligent Wireless Technologies Laboratory (IWT) in 2017 as a research assistant where his work, under the supervision of Prof. Pedram Mousavi, was focused on designing battery-less wireless sensors for 5G IoT applications. In 2020, as an Alberta Innovates Scholar, Nabil started pursuing his Ph.D. degree under the supervision of Prof. Ashwin Iyer at the Electrical and Computer Engineering Department, University of Alberta, Edmonton, Canada. He is focused on designing Battery-less wireless sensors.
Abstract: A novel zero-power wireless sensor architecture is proposed and demonstrated. The proposed wireless sensor, which is a passive sensor, combines UHF RFID and a capacitive sensor to enable the reading of physical and chemical parameters wirelessly, without compromising much on the read-range of conventional RFID tags. The sensor alters the phase of the backscattered RFID signal, which is detected at the receiver using a non-coherent IQ demodulator. Due to the universal nature of this architecture, any type of sensor, such as temperature, humidity, water level sensor, can be realized.
Mahdi Bedani: Design of Over-the-Air Measurement Systems for Characterization of 5G Communication Devices
Abstract: A portable near field (NF) measurement system is implemented in a mini anechoic chamber to debug and characterize the integrated devices deployed in the fifth generation (5G) communication technology. In this system, the NF data of the device under test (DUT) is acquired through novel methods and the obtained data is utilized to evaluate the performance of various wireless sub-systems such as micro-millimeter wave circuits and integrated antennas. The main advantage of the proposed setup over the conventional systems is its capability to characterize Integrated (Reconfigurable, Active, Phase Array …) Antennas where there is no access to the antenna to measure, separately. Since the integrated antennas are planed to be deployed in large scale in 5G technology, providing the telecommunication companies with such an economical measurement setup enables them to test their wireless products quickly and accurately, which is critical for those who are seeking opportunities in the 5G market.
March 31
Christopher Barker: Power-conserving field transformations using passive metasurfaces
Abstract: The ability of metasurfaces to manipulate waves over short distances make these devices attractive for applications ranging from microwaves to optics. These metasurfaces have a great ability to manipulate wavefronts making them desirable for applications such as antenna radomes and cloaking. However, these applications can be limited due to a requirement of local power conservation over the surface. This presentation will show how local power conservation effects the ability to achieve a desired field pattern and how recent works have been able to satisfy this constraint while still producing a desired field transformation.
Navid Hosseini: Selective Multivariable Analysis of Multicomponent Mixtures Using Harmonics of Planar EM Sensors
Christopher Barker: Power-conserving field transformations using passive metasurfaces
Abstract: In recent years, selectivity have been a subject of many researches due to its practical challenges. The main issue is the limited number of output data which confines the degree of freedom for solving the more unknown of the problem.
The microwave resonators as the detecting devices can be useful for gathering the required information in the experiment. Their resonance shift is one of the features that is mostly utilized for sensing purposes. But for detection of multi-variable parameters, more than one independent feature is required. For overcoming this bottleneck, a new material characteristic is demanded for generating and defining the new independent features.
The rings are type of resonating structures that generate multiple harmonics in their frequency response. In order to make these elements changing independently, the variant permittivity profile of the materials under the test as a new parameter can be considered.