École Polytechnique de Montréal

About: École Polytechnique de Montréal is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Finite element method & Computer science. The organization has 8015 authors who have published 18390 publications receiving 494372 citations.

Study of a CPW inductively coupled slot antenna

Abstract: Coplanar waveguide (CPW) fed slot antennas are attractive due to fabrication simplicity and ease of integration with active devices. A new concept for exciting slots with a CPW line based on inductive coupling is presented. It is described how this coupling structure can be designed to tune the impedance of the antenna over a wide range. Single elements and arrays designed for 5- and 25-GHz operation are described. Simulated and measured characteristics are presented. This new coupling topology is particularly suitable for series-fed array configurations and broad-band design.

Applications of carbon nanotubes-based biomaterials in biomedical nanotechnology.

Abstract: One of the facets of nanotechnology applications is the immense opportunities they offer for new developments in medicine and health sciences. Carbon nanotubes (CNTs) have particularly attracted attention for designing new monitoring systems for environment and living cells as well as nanosensors. Carbon nanotubes-based biomaterials are also employed as support for active prosthesis or functional matrices in reparation of parts of the human body. These nanostructures are studied as molecular-level building blocks for the complex and miniaturized medical device, and substrate for stimulation of cellular growth. The CNTs are cylindrical shaped with caged molecules which can act as nanoscale containers for molecular species, well required for biomolecular recognition and drug delivery systems. Endowed with very large aspect ratios, an excellent electrical conductivity and inertness along with mechanical robustness, nanotubes found enormous applications in molecular electronics and bioelectronics. The ballistic electrical behaviour of SWNTs conjugated with functionalization promotes a large variety of biosensors for individual molecules. Actuative response of CNTs is considered very promising feature for nanodevices, micro-robots and artificial muscles. An description of CNTs based biomaterials is attempted in this review, in order to point out their enormous potential for biomedical nanotechnology and nanobiotechnology.

Comparative analysis of body surface potential distribution during cardiac pacing

Abstract: Body surface potential map (BSPM) pace-mapping is a system and method that can be used in medicine to localize with precision the site of origin of abnormal cardiac electrical activity and to guide the positioning of a catheter over this site of origin, such as the site of ventricular preexcitation in patients with the Wolff-Parkinson-White syndrome or the focus of ectopic activity in patients with tachycardia. Body surface potential distributions are measured with a large number of electrodes, e.g. 24 to 128, distributed over the entire torso surface. The electrical signals are first amplified, converted into digital data and treated to remove electrical or muscle artifacts. Data recorded during abnormal activation (reference beat) are aligned with data recorded during cardiac pacing (paced beat) so as to maximize the average value of the correlation coefficient between the reference and the paced potential distributions during a preset time interval following the beginning of the QRS complex. Reference and paced maps showing color-coded isopotential contour lines are displayed side by side for the same time instant. Visual analysis of these maps according to previously published criteria determines the relative position of the pacing catheter with respect to the focus of abnormal activation, and gives information so as to guide the catheter toward the focus.

Deembedding static nonlinearities and accurately identifying and modeling memory effects in wide-band RF transmitters

Abstract: In this paper, a robust modeling technique for memoryless wide-band radio frequency transmitters using a dynamic exponential weighted moving average algorithm is developed and tested. To improve the relatively limited accuracy of the conventional Wiener model in predicting the response of dynamic nonlinear transmitters, a new augmented Wiener model is proposed along with its parameter-identification procedure. The accuracy of the augmented Wiener model is compared with that of the conventional Wiener model by using an L-band 60-W peak-envelope-power GaAs field-effect-transistor push-pull amplifier-based transmitter, which is driven by a two-carrier wide-band code-division multiple-access signal.