Ahmad Hassan

Prof. Ahmad Hassan

Electrical Engineering, Polytechnique Montréal, Montréal, Quebec, Canada
orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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7 December 2018 in IEEE Access
Verified
Journal Article
Open access
Ahmad HassanAhmad Hassan
Ahmad Hassan
YSYvon Savaria
Yvon Savaria
MSMohamad Sawan
Mohamad Sawan
In many leading industrial applications such as aerospace, military, automotive, and deep-well drilling, extreme temperature environment is the fundamental hindrance to the use of microelectronic devices. Developing an advanced technology with robust electrical and material properties dedicated for high-temperature environments represents a significant progress allowing to control and monitor the harsh environment regions. It may avoid using cooling structures while improving the reliability of the whole electronic systems. As a wide bandgap semiconductor, gallium nitride is considered as an ideal candidate for such environments, as well as in high-power and high-frequency applications. We review in this paper the main reasons that offer superiority to GaN devices over better-known technologies such as silicon (Si), silicon-on-insulator, gallium arsenide (GaAs), silicon germanium (SiGe), and silicon carbide (SiC). The theory of operation and main challenges at high temperature are discussed, notably those related to materials and contacts. In addition, the main limitations of GaN, including the technological (thermal and chemical) and intrinsic (current collapse and device self-heating) features are provided. In addition, the GaN devices recently developed for high-temperature applications are examined.

31 May 2018 in IEEE Transactions on Very Large Scale Integration (VLSI) Systems
Verified
Journal Article
Closed access
Ahmad HassanAhmad Hassan
Ahmad Hassan
YSYvon Savaria
Yvon Savaria
Mohamad SawanMohamad Sawan
Mohamad Sawan
Several industrial applications require specific electronic systems installed in harsh environments to perform measurements, monitoring, and control tasks such as in space exploration, aerospace missions, automotive industries, down-hole oil and gas industry, and geothermal power plants. The extreme environment could be surrounding high-, low-, and wide-range temperature, intense radiation, or even a combination of above conditions. We review, in this paper, the main leading applications that demand advanced technologies to fit the unconventional requirements of extreme operating conditions, discussing their main merits and limits compared to established and emerging technologies in this field, including silicon (Si), silicon on insulator (SOI), silicon germanium (SiGe), silicon carbide (SiC) as well as III-V semiconductors particularly the gallium nitride (GaN) semiconductor. In spite of successfully exceeding extreme conditions borders by developing advanced semiconductor devices dedicated for harsh environments, especially in high-temperature applications, the packaging challenges are still limiting the reliability of the developed technologies. Those challenges are examined in this review in terms of limitations and proposed solutions.

14 April 2019 in Sensors
Verified
Journal Article
Open access
PDF file
Ahmad HassanAhmad Hassan
Ahmad Hassan
Mohamed AliMohamed Ali
Mohamed Ali
ATAref Trigui
Aref Trigui
YSYvon Savaria
Yvon Savaria
Mohamad SawanMohamad Sawan
Mohamad Sawan
A fully-integrated data transmission system based on gallium nitride (GaN) high-electron-mobility transistor (HEMT) devices is proposed. This system targets high-temperature (HT) applications, especially those involving pressure and temperature sensors for aerospace in which the environmental temperature exceeds 350 °C. The presented system includes a front-end amplifying the sensed signal (gain of 50 V/V), followed by a novel analog-to-digital converter driving a modulator exploiting the load-shift keying technique. An oscillation frequency of 1.5 MHz is used to ensure a robust wireless transmission through metallic-based barriers. To retrieve the data, a new demodulator architecture based on digital circuits is proposed. A 1 V amplitude difference can be detected between a high-amplitude (data-on) and a low-amplitude (data-off) of the received modulated signal. Two high-voltage supply levels (+14 V and −14 V) are required to operate the circuits. The layout of the proposed system was completed in a chip occupying 10.8 mm2. The HT characterization and modeling of integrated GaN devices and passive components are performed to ensure the reliability of simulation results. The performance of the various proposed building blocks, as well as the whole system, have been validated by simulation over the projected wide operating temperature range (25–350 °C).

23 December 2021 in Electronics
Verified
Journal Article
Open access
PDF file
Ahmad HassanAhmad Hassan
Ahmad Hassan
JNJean-Paul Noël
Jean-Paul Noël
YSYvon Savaria
Yvon Savaria
Mohamad SawanMohamad Sawan
Mohamad Sawan
As a wide bandgap semiconductor, Gallium Nitride (GaN) device proves itself as a suitable candidate to implement high temperature (HT) integrated circuits. GaN500 is a technology available from the National Research Council of Canada to serve RF applications. However, this technology has the potential to boost HT electronics to higher ranges of operating temperatures and to higher levels of integration. This paper summarizes the outcome of five years of research investigating the implementation of GaN500-based circuits to support HT applications such as aerospace missions and deep earth drilling. More than 15 integrated circuits were implemented and tested. We performed the HT characterization of passive elements integrated in GaN500 including resistors, capacitors, and inductors up to 600 °C. Moreover, we developed for the first time several digital circuits based on GaN500 technology, including logic gates (NOT, NAND, NOR), ring oscillators, D Flip-Flop, Delay circuits, and voltage reference circuits. The tested circuits are fabricated on a 4 mm × 4 mm chip to validate their functionality over a wide range of temperatures. The logic gates show functionality at HT over 400 °C, while the voltage reference circuits remain stable up to 550 °C.

3 October 2020 in Sensors
Verified
Journal Article
Open access
PDF file
OEOUAFAA ETTAHRI
OUAFAA ETTAHRI
AOAZIZ OUKAIRA
AZIZ OUKAIRA
Mohamed AliMohamed Ali
Mohamed Ali
Ahmad HassanAhmad Hassan
Ahmad Hassan
MNMorteza Nabavi
Morteza Nabavi
ALAhmed Lakhssassi
Ahmed Lakhssassi
This paper proposes a real-time thermal monitoring method using embedded integrated sensor interfaces dedicated to industrial integrated system applications. Industrial sensor interfaces are complex systems that involve analog and mixed signals, where several parameters can influence their performance. These include the presence of heat sources near sensitive integrated circuits, and various heat transfer phenomena need to be considered. This creates a need for real-time thermal monitoring and management. Indeed, the control of transient temperature gradients or temperature differential variations as well as the prediction of possible induced thermal shocks and stress at early design phases of advanced integrated circuits and systems are essential. This paper addresses the growing requirements of microelectronics applications in several areas that experience fast variations in high-power density and thermal gradient differences caused by the implementation of different systems on the same chip, such as the new-generation 5G circuits. To mitigate adverse thermal effects, a real-time prediction algorithm is proposed and validated using the MCUXpresso tool applied to a Freescale embedded sensor board to monitor and predict its temperature profile in real time by programming the embedded sensor into the FRDM-KL26Z board. Based on discrete temperature measurements, the embedded system is used to predict, in advance, overheating situations in the embedded integrated circuit (IC). These results confirm the peak detection capability of the proposed algorithm that satisfactorily predicts thermal peaks in the FRDM-KL26Z board as modeled with a finite element thermal analysis tool (the Numerical Integrated elements for System Analysis (NISA) tool), to gauge the level of local thermomechanical stresses that may be induced. In this paper, the FPGA implementation and comparison measurements are also presented. This work provides a solution to the thermal stresses and local system overheating that have been a major concern for integrated sensor interface designers when designing integrated circuits in various high-performance technologies or harsh environments.

25 February 2022 in IEEE Access
Verified
Journal Article
Open access
Mohamed AliMohamed Ali
Mohamed Ali
Ahmad HassanAhmad Hassan
Ahmad Hassan
MHMohammad Honarparvar
Mohammad Honarparvar
MNMorteza Nabavi
Morteza Nabavi
YAYves Audet
Yves Audet
YSYvon Savaria
Yvon Savaria
We present in this paper design considerations and implementation challenges of a proposed versatile SoC/SiP sensor interface intended for industrial applications. The proposed interface involves high-voltage circuits such as class-D power amplifiers, gate drivers, level shifters, and electrical isolators. Also, it includes low-voltage blocks like programmable gain amplifiers and ADCs. In addition, DC-to-DC converters are used to supply the various building blocks of the projected sensor interface. The key challenges for implementing each block are discussed in this paper. Also, the technological aspects to support the proposed SoC/SiP solution are given. Moreover, the different available packaging technologies to implement the intended SiP solution are discussed in addition to the thermal aspects associated with the system packaging.