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Ontario Tech acknowledges the lands and people of the Mississaugas of Scugog Island First Nation.

We are thankful to be welcome on these lands in friendship. The lands we are situated on are covered by the Williams Treaties and are the traditional territory of the Mississaugas, a branch of the greater Anishinaabeg Nation, including Algonquin, Ojibway, Odawa and Pottawatomi. These lands remain home to many Indigenous nations and peoples.

We acknowledge this land out of respect for the Indigenous nations who have cared for Turtle Island, also called North America, from before the arrival of settler peoples until this day. Most importantly, we acknowledge that the history of these lands has been tainted by poor treatment and a lack of friendship with the First Nations who call them home.

This history is something we are all affected by because we are all treaty people in Canada. We all have a shared history to reflect on, and each of us is affected by this history in different ways. Our past defines our present, but if we move forward as friends and allies, then it does not have to define our future.

Learn more about Indigenous Education and Cultural Services

Langis Roy

Langis Roy
PhD, PEng

Deputy Provost


Department of Electrical, Computer and Software Engineering
Faculty of Engineering and Applied Science

Langis Roy is an international wireless sensor technology expert leading a new era of Graduate Studies at Ontario Tech University

English, French

  • PhD - Electrical Engineering Carleton University, Ottawa, Ontario 1993
  • MEng - Electrical Engineering Carleton University, Ottawa, Ontario 1989
  • BASc - Electrical Engineering University of Waterloo, Waterloo, Ontario 1987

Advances in Tunable Microwave Ferrite-LTCC Components

Paris, France September 11, 2015

WM04 Workshop on MM-Wave Multilayer MCM/SoP and Heterogeneous Integration Techniques, European Microwave Week

Characterization of GaN-based HEMTs as Varactor Diode Devices

Paris, France September 6, 2015

European Microwave Week 2015

A Novel Multi-Layer Electromagnetic Band Gap Structure (EBG) Comprised of 3D Lattice of Square Rings

Carleton University, Ottawa, Ontario August 11, 2015

IEEE International Conference on Numerical Elec­tromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Ap­plications (NEMO)

Modeling Substrate Integrated Waveguide Structures Using Effective Material Properties

Carleton University, Ottawa, Ontario August 11, 2015

IEEE International Conference on Numerical Elec­tromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Ap­plications (NEMO),

Modeling and Simulation of a Partially-Magnetized Ferrite LTCC Circulator

Carleton University, Ottawa, Ontario August 11, 2015

IEEE International Conference on Numerical Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications

Circulateur LTCC Ferrite Large-Bande à Structures Empilées en Bande K

Bordeaux, France June 3, 2015

19èmes Journées Nationales Microondes

Health Implications of Radio-Wave Exposure

Ottawa, Ontario February 2, 2015

Discovery Café, Blackburn Community Centre

How Safe is Wireless Technology

Ottawa, Ontario October 1, 2014

Innovations in Antenna Engineering, Faculty of Engineering and Design, Carleton University Talks, Ottawa Public Library

Schottky-contact Plasmonic Rectenna for Biosensing

Ottawa, Ontario June 3, 2013

Photonics North 2013

Zero-biased Optically Controlled RF Switch in 0.13μm CMOS Technology

Singapore October 18, 2011

IEEE 2011 International Topical Meeting on Microwave Photonics Conference

A New Optically Controlled CdS-Polymer Capacitor for Tunable Microwave Components

Manchester, United Kingdom October 9, 2011

European Microwave Week 2011

A 60 GHz System-on-Package Balanced Antipodal Vivaldi Antenna with Stepped Dielectric Director (BAVA-SDD) in LTCC

Manchester, United Kingdom October 11, 2011

European Microwave Week 2011

Electric Energy and Power Educational Programs Development Workshop

Vancouver, British Columbia June 26, 2011

118th ASEE Annual Conference and Exposition

60 GHz SoP Active Array Design

Williamsburg, Virginia March 27, 2011

The 27th International Review of Progress in Applied Computational Electromagnetics

The Field-Programmable Microwave Substrate

Published in IEEE Transactions on Microwave Theory and Techniques November 1, 2016
Nathan Jess, Barry A. Syrett & Langis Roy

A novel low-loss programmable microwave waveguide is demonstrated, allowing reconfigurable microwave circuits with similar levels of programmability as that seen in field-programmable gate arrays. The waveguide is realized with a field-programmable microwave substrate (FPMS), consisting of small unit cells that can be individually reconfigured to have a range of positive dielectric constants or a negative dielectric constant. Programmable waveguides, amplifiers, and oscillators are demonstrated. The proposed FPMS concept promises a new era of programmable microwave circuit design for cognitive radio, the Internet of things, and self-healing/adaptive systems.

View more - The Field-Programmable Microwave Substrate

Surface Plasmon Enhanced Photodetectors Based on Internal Photoemission

Published in Journal of Photonics for Energy October 27, 2016
Mohammad Alavirad, Langis Roy & Pierre Berini

Surface plasmon photodetectors are of broad interest. They are promising for several applications including telecommunications, photovoltaic solar cells, photocatalysis, color-sensitive detection, and sensing, as they can provide highly enhanced fields and strong confinement (to subwavelength scales). Such photodetectors typically combine a nanometallic structure that supports surface plasmons with a photodetection structure based on internal photoemission or electron–hole pair creation.

View more - Surface Plasmon Enhanced Photodetectors Based on Internal Photoemission

Characterization and Analytical Modelling of GaN HEMT-Based Varactor Diodes

Published in IET Electronics Letters October 16, 2015
A. Hamdoun, L. Roy, M. Himdi & O. Lafond

Varactor diodes fabricated in 0.5 and 0.15 µm GaN HEMT (high-electron-mobility transistor) processes are modelled. The devices were characterized via DC and RF small-signal measurements up to 20 GHz, and fitted to a simple physical equivalent circuit. Approximate analytical expressions containing empirical coefficients are introduced for the voltage dependency of capacitance and series resistance. The analytical solutions agree remarkably well with the experimentally extracted C–V curves and can be used as a general model to represent the nonlinear behaviour of GaN-based varactors devices.

View more - Characterization and Analytical Modelling of GaN HEMT-Based Varactor Diodes

Study of a Ferrite LTCC Multifunctional Circulator With Integrated Winding

Published in IEEE Transactions on Components, Packaging and Manufacturing Technology July 1, 2015
Shicheng Yang, Didier Vincent, Joey R. Bray & Langis Roy

This paper shows a study of a new ferrite low-temperature cofired ceramic (LTCC) circulator with integrated winding. The external magnets used in traditional circulators must be strong to overcome the ferrite's demagnetization factor. The novel circulator presented herein uses an embedded winding within the ferrite to magnetize the material from the inside, thereby significantly reducing the demagnetization effects. Because of the controllability of the bias field, the resulting device is also multifunctional: when the windings are energized by a current, the device operates as a dynamic circulator in which the circulation direction can be changed by switching the direction of the current.

View more - Study of a Ferrite LTCC Multifunctional Circulator With Integrated Winding

Vivaldi Antenna for MM-Wave Communications

Published in High Frequency Electronics October 1, 2014
Greg Brzezina, Rony E. Amaya, Aldo Petosa & Langis Roy

The proliferation of portable devices such as smart phones, tablets, and laptops has resulted in an increased demand for mobile broadband wireless, and with the expected growth in the Internet of Things and Machine-to-Machine communications, this increase is expected to exceed the current available capacity, and higher frequency bands will also need to be adopted. Serious consideration is being given to the 60 GHz Industrial, Scientific, and Medical (ISM) band by the Wireless Gigabit Alliance (WiGig) to develop and promote the adoption of multi-gigabit speed wireless communication technology based on the IEEE 802.11ad protocol, and by industry involved in developing fifth generation (5G) communication systems. These systems will require the development of antenna array technology with beam scanning capability, since high-gain (narrow beam) patterns that can be steered to track mobile devices, or change shape to reduce interference will be needed. This paper presents the design of a tapered slot antenna, known as a balanced antipodal Vivaldi antenna, and is seen to be a promising candidate for 60 GHz wireless communications.

View more - Vivaldi Antenna for MM-Wave Communications

A New Hybrid-Polymer Optically Tunable Dielectric and its Measurement Using a Variation of the Split-Post Dielectric Resonator

Published in Microwave and Optical Technology Letters March 27, 2013
Nathan Jess, Barry Syrett, Steve McGarry & Langis Roy

An apparatus based on the split-post dielectric resonator was designed and verified for the purpose of measuring the microwave properties of optically sensitive materials. The apparatus was then used to confirm that a material consisting of micro sized photoconductive particles added to an insulating polymer would show an increase in the effective dielectric constant while under optical illumination. The semiconductor-polymer composite showed a change in dielectric constant and dielectric loss tangent from 5.5 to 6.1 and 0.05 to 0.09 respectively.

View more - A New Hybrid-Polymer Optically Tunable Dielectric and its Measurement Using a Variation of the Split-Post Dielectric Resonator

1 W, Highly Efficient, Ultra-Broadband Non-Uniform Distributed Power Amplifier in GaN

Published in IEEE Microwave and Wireless Components March 29, 2013
Xing Zhou, Langis Roy & Rony E. Amaya

This letter describes the design and implementation of a highly linear, ultra-broadband non-uniform asymmetric distributed MMIC power amplifier in GaN, delivering 1 W of output power and suitable for operation at frequencies up to 6.5 GHz. The GaN HFETs used here have a gate length of 500 nm, and breakdown-voltages exceeding 100 V while exhibiting an fT of approximately 30 GHz. A non-uniform asymmetric distributed topology is used to achieve ultra-broadband performance. CW measurements carried out at nominal bias between 0.5 GHz and 6.5 GHz yielded a maximum PAE of 38.1% at 0.5 GHz, with PAE higher than 20% over the entire band, while achieving Pout > 30 dBm.

View more - 1 W, Highly Efficient, Ultra-Broadband Non-Uniform Distributed Power Amplifier in GaN

Schottky-Contact Plasmonic Dipole Rectenna Concept for Biosensing

Published in Optics Express February 25, 2013
Mohammad Alavirad, Saba Siadat Mousavi, Langis Roy & Pierre Berini

Nanoantennas are key optical components for several applications including photodetection and biosensing. Here we present an array of metal nano-dipoles supporting surface plasmon polaritons (SPPs) integrated into a silicon-based Schottky-contact photodetector.

View more - Schottky-Contact Plasmonic Dipole Rectenna Concept for Biosensing

Ultra Low Power CMOS-Based Sensor for On-Body Radiation Dose Measurements

Published in IEEE Journal on Emerging and Selected Topics in Circuits and Systems March 15, 2012
M. Arsalan, A. Shamim, M. Shams, N. G. Tarr & L. Roy

For the first time, a dosimeter employing two floating gate radiation field effect transistors (FGRADFET) and operating at mere 0.1 V is presented. The novel dosimeter requires no power during irradiation and consumes only 1 during readout. Besides the low power operation, structural changes at the device level have enhanced the sensitivity of the dosimeter considerably as compared to previous designs. The dosimeter is integrated with a wireless transmitter chip, thus eliminating all unwanted communication and power cables. It has been realized monolithically in DALSA's 0.8 complementary metal-oxide-semiconductor process and characterized with X-ray and γ-ray sources.

View more - Ultra Low Power CMOS-Based Sensor for On-Body Radiation Dose Measurements

5 GHz LTCC-Based Aperture- Coupled Wireless Transmitter for SoP Applications

Published in PIER C January 1, 2012
L. Roy

A novel System-on-Package (SoP) implementation is presented for a transmitter (TX) module which makes use of electromagnetic coupling between the TX chip and the package antenna. The TX chip is realized in 0.13 μm CMOS process and comprises an on-chip antenna, which serves as the oscillator's inductor as well. The TX chip is housed in a Low Temperature Co-fired Ceramic (LTCC) package with a patch antenna. The on-chip antenna feeds the LTCC patch antenna through aperture coupling, thus negating the need for RF buffer amplifiers, matching elements, baluns, bond wires and package transmission lines. This is the first ever demonstration of wireless-interconnect between on-chip and package antennas which increases the gain and range of the TX module manyfold with respect to the on-chip antenna alone.

Appointed to the Board of Directors

Canadian Association for Graduate Studies (CAGS) January 1, 2017

Appointed to this role for a two-year term from 2017 to 2018, Dr. Roy is committed to the promotion of graduate education and university research through meetings, publications and advocacy. CAGS brings together 58 Canadian universities with graduate programs and the three federal research-granting agencies, as well as other institutions and organizations with an interest in graduate studies.

Appointed to the Strategic Engagement Editorial Board

Council of Ontario Universities (COU) January 1, 2017

Dr. Roy has been appointed to this COU board for a two-year term from 2017 to 2018. The board is part of a year-long campaign to engage students and parents in province-wide dialogue about future economic needs across all sectors, and determine how universities can contribute to a brighter future for everyone.

Appointed to the NSERC Advisory Committee on University-Industry Grants (ACUIG)

January 1, 2017

Dr. Roy has been appointed to the ACUIG for a three-year term, from 2017 to 2019. This multidisciplinary committee has broad experience in university-industry interactions. The ACUIG makes funding recommendations for large scale NSERC Collaborative Research and Development applications as well as Industrial Research Chair applications, taking into account the recommendations of site visit committees and external peer reviews.

Appointed to the NSERC Research Tool and Instrument Selection Committee

January 1, 2016

An appointed member of this committee from 2016 to 2018, Dr. Roy plays a role in evaluating and awarding Research Tools and Instruments (RTI) grants which foster and enhance the discovery, innovation and training capability of university researchers in the natural sciences and engineering (NSE).

Best Conference Paper Award

European Wireless Technology Conference (EuWiT) October 27, 2008

Awarded for his co-authored paper entitled, Wireless Interconnect Between On-Chip and LTCC Antennas for System-in-Package Applications, at the EuWiT conference held in Amsterdam, Netherlands.

Institute of Electrical and Electronics Engineers (IEEE)

Ontario Aerospace Consortium

Professional Engineers Ontario