ACTIVE TERAHERTZ DIFFERENTIATOR USING PMUT ARRAY
Simple and accurate method to actively modulate THz waves in reflection mode using a PMUT array for the future of data transmission in THz telecommunications and for novel THz imaging methods
The challenge in modulating electromagnetic signals in the terahertz region of the electromagnetic spectrum
- The success of the rapid growth of information technology is closely linked to our ability to modulate and demodulate a signal, whether in the frequency or time domain.
- With the highly anticipated venue of the THz frequency range (i.e. from 0.1 THz to 10 THz) in the telecommunications world, a differentiator device that enables identifying the high frequency component of a signal, such as peak detection, is a mandatory tool to meet future real-time and high-throughput information processing.
- At the same time, with the peculiar properties of THz waves to penetrate visibly opaque materials, THz imaging applications see an increasing demand in research activities, and will undoubtedly require image differentiator functions to sharpen image rendering.
- Recent demonstrations of THz modulation have involved active semiconductor metamaterial surfaces or have used grating-based micromirrors for frequency offset tuning. However, a wideband and active differentiator in the THz frequency band has yet to be demonstrated.
- Although a few attempts have been made to introduce temporal and spatial differentiators in the THz range, none of them work dynamically in the time-domain and/or space-domain, i.e. with an external control signal, which is required to efficiently couple information from an electronic signal to the THz radiation.
Terahertz modulation system using piezoelectric micromachined ultrasonic transducers
- A simple method to differentiate a THz pulse by inducing tiny phase changes on the THz beam path using a piezoelectric micromachined ultrasonic transducer array working on its resonant response to realize the first-order temporal differentiation in the THz region.
- Each unit cell acts as a single micromirror to modulate the full THz bandwidth in the time-domain.
- The piezo-resonance is excited by an external single-frequency electric field, which induces tiny temporal (i.e. in the femtosecond timescale) variations in the THz beam path that allows undertaking a differential measurement.
- The lock-in detection of THz pulses at the PMUTs resonant frequency is proportional to the first-order derivative of the incident THz pulse
- This modulator makes it possible to carry out the fundamental mathematical operation of differentiation i.e., supplying an output proportional to the derivative of the input.
- Such differentiators are highly anticipated for the future of data transmission in THz telecommunications and for novel THz imaging methods.
- Technology developed by Prof. Francois Blanchard and Prof. Frédéric Nabki, (Department of Electrical Engineering, École de technologie supérieure (ÉTS)).
- Active surface (2D array) to produce first-order derivative function of a THz signal.
- Able to support a wide range of THz applications, from edge detection for imaging, to peak detection schemes for telecommunication systems, as well as improving the sensitivity of THz spectroscopic methods.
- As it is a matrix modulator with each of the transducers electronically controllable, development of new spatiotemporal computational information retrieval in the THz frequency range is highly anticipated.
- Imaging systems
- Therapeutics devices
- Technology available for licensing
- Provisional patent application filed
École de Technologie supérieure (ÉTS)
François Blanchard, Professor, Department of Electrical Engineering
Prof. Blanchard has joined ÉTS in 2015 and he recently obtained the ÉTS Research Chair on terahertz (THz) optoelectronic. Among his research achievements, he is internationally recognized for his research on intense terahertz pulse generation and the development of a video-rate terahertz microscope system. Since 2015, he has supervised 7 M.Sc.A, 4 Ph.D., and 2 PDFs. and has given 10 invited talks at national/international conferences. Additionally, professor Blanchard cumulates 10 years of industrial field experiences in non-destructive testing of materials.
Frédéric Nabki, Professor, Department of Electrical Engineering
Prof. Nabki received the B.Eng. degree in Electrical Engineering with Honors from McGill University in 2003, where he graduated with distinction. In 2009, he completed a Ph.D. degree in Electrical Engineering at McGill University in RFIC and MEMS. From 2008 to 2016 he was a Professor in microelectronics engineering at UQAM. He is now an Associate Professor in the Department of Electrical Engineering of the École de technologie supérieure (ETS), a constituent of the University of Quebec. Nabki’s research interests include microelectromechanical systems (MEMS) and RF/analog microelectronics, the integrating of MEMS devices with CMOS phase-locked loops, ultra-wideband transceivers, and MEMS interface circuits.