In collaboration with the Poly-Grames Research Center, IEEE Student Branch of Polytechnique and INRS, STARaCom, and Academy of Science of the Royal Society of Canada, the IEEE Montreal Section and MTT Montreal IEEE Chapter are organizing THz Science and Technology Seminar (TSTS) Series, which will be delivered exclusively online by distinguished THz researchers, engineers, and leaders in the world to present state-of-the-art THz R&D progress, education, and applications. This TSTS series is made possible thanks to the sponsorship and conclusion of the NSERC-Huawei Industrial Research Chair Program. Near-field Terahertz Networking Abstract: The recent dramatic growth in interest in the use of high-frequency (millimeter-wave and terahertz) carrier waves for wireless communications has spurred a great deal of research activity. In some cases, such as fixed point-to-point backhaul, systems operating above 100 GHz are already in or nearing commercial deployment. On the other hand, significant research challenges remain for the deployment of local area networks, which must manage factors such as user mobility and line-of-sight blockage of directional beams. Interestingly, such networks may often be able to operate in a regime in which most or all of the broadcast sector is located in the near field of the transmitter. This possibility opens up a host of new ideas for wave front engineering, in particular wave fronts that can only exist in the electromagnetic near field. Here, we discuss a few examples, focusing on the class of wave fronts that can be engineered to curve around an intervening obstacle, delivering data to a user located in the shadow of the obstacle. This near-field effect presents an intriguing alternative to the popular notion of intelligent reflecting surfaces for blockage mitigation. Co-sponsored by: PolyGrames, STARaCom, Academy of Science of the Royal Society of Canada Speaker(s): , Professor Daniel Mittleman Virtual: https://events.vtools.ieee.org/m/386141

The ability of electromagnetic waves to penetrate through various building materials, together with advances in design of ultra-wideband compact radar modules, has made see-thru-wall technology, also known as Through-the-wall radar imaging (TWRI), of increasing importance in a wide range of both civilian and defense applications. In this lecture, an overview of various TWRI technologies, including the latest research in several areas important in the design of TWRI systems, will be presented. Electromagnetic-based techniques for wall parameter estimation to mitigate the adverse wall effects and enhance the efficient imaging and classification of targets within and/or behind walls will be discussed. For efficient imaging, details of fast polarimetric and tomographic based imaging algorithms for both 2D and 3D scenarios will be given, and imaging results for various realistic scenarios using both numerical simulations and laboratory measurements will be presented, Development of wideband and ultrawideband antenna arrays, which are essential in successful implementation of see-thru-wall technology, together with hardware descriptions of two constructed portable systems will conclude the presentation. Throughout, I will include a personal perspective from my own two-decade journey in this interdisciplinary research area. Speaker(s): Prof. Ahmad Hoorfar, Bldg: Pavillon Principal, B 600.16, la Galerie Rolland, 2500 Chem. de Polytechnique, Montréal, Quebec, Canada, H3T 1J4

The problem of imaging of objects within or through multilayered dielectric media appears in many areas, including those in ground-penetrating radar (GPR) imaging, through-the-wall radar imaging (TWRI), intra-wall and subsurface imaging, and medical imaging. These general areas cover many important defense and civilian applications such as those in counterterrorism and law enforcement operations, firefighting, earthquake rescue missions, detection of buried subsurface objects and minerals in GPR, millimeter wave imaging of concealed weapons and contraband carried by personnel, to name a few. In many situations, however, the dielectric media induce shadowing effects on targets, resulting in image degradation and errors in geo-locating or, possibly, complete masking of targets. Furthermore, in most practical situations the imaging of targets should be done in real-time, requiring the development of fast data acquisition schemes as well as highly efficient microwave imaging techniques that can fully account for wave propagation through various dielectric layers or walls. In this lecture, a comprehensive overview of various image reconstruction techniques for objects in stratified media will be given for both SAR-based and multiple-input multiple-output (MIMO) based systems, and for both real-time imaging and sparsity-based imaging scenarios. For the former, we will describe the use of efficient 2D and 3D Diffraction Tomography (DT) techniques which use first order Born approximation together with successive implementations of spatial fast-Fourier transform (FFT) and inverse-FFT (IFFT), to arrive at high-resolution images. Such fast-imaging techniques, however, do not address the problem posed by long data acquisition time associated with most microwave-imaging scenarios. To address this problem, assuming a sparse target space, one can resort to the use of Compressive Sensing (CS) to significantly reduce the number of antennas and/or collected frequency points. In our implementation of CS, the wall or multilayered media effects are accurately and efficiently accounted for in the sparse-image reconstruction through the use of approximate expressions for the Green’s functions of multi-layered lossy dielectric medium. In particular, the use of total variation minimization (TVM) and its advantages over the l1-norm minimization, which is often used in the standard radar implementation of CS, will be detailed. Numerical and experimental results for DT-based and CS-based radar imaging in various GPR and TWRI scenarios will be given in the presentation. Speaker(s): Prof. Ahmad Hoorfar, Bldg: Pavillon Principal, B 600.16, la Galerie Rolland, 2500 Chem. de Polytechnique, Montréal, Quebec, Canada, H3T 1J4

An InAs/InP quantum-dash mode-locked laser (QD-MLL) with phase-locked comb lines is an excellent optical source and a microwave source for, respectively, optical and wireless transmission. In this talk, a duplex radio over fiber (RoF) link using a QD-MLL for RoF transmission is reported. A few implementation issues including phase noise impairment, MIMO transmission, and photonic integrated implementation will be discussed. RoF links with integrated sensing and communication (ISAC) functions for next generation wireless communications (6G) applications will also be discussed. Laser à verrouillage de mode InAs/InP tirets quantiques (Quantum-Dash) pour radio duplex sur liaisons fibre optique Un laser à verrouillage de mode quantique InAs/InP (QD-MLL) avec des lignes de peigne à verrouillage de phase est une excellente source optique et une source micro-ondes pour, respectivement, la transmission optique et sans fil. Dans cet exposé, une liaison radio duplex sur fibre (RoF) utilisant un QD-MLL pour la transmission RoF est rapportée. Quelques problèmes de mise en œuvre, notamment la dégradation du bruit de phase, la transmission MIMO et la mise en œuvre photonique intégrée, seront abordés. Les liens RoF avec des fonctions intégrées de détection et de communication (ISAC) pour les applications de communications sans fil (6G) de nouvelle génération seront également abordés. Co-sponsored by: National Research Council, Canada. Optonique. Speaker(s): Prof. Jianping Yao (University of Ottawa), Virtual: https://events.vtools.ieee.org/m/388262

Webinar by the IEEE Montreal Section Power and Energy Chapter The IEEE Montreal Section is inviting all interested IEEE members and non-members to this webinar. Speaker(s): Dr. David Laverty, Reader (Full Professor) Virtual: https://events.vtools.ieee.org/m/388158