COM DEV Canada

Kanata, Canada

COM DEV Canada

Kanata, Canada

Time filter

Source Type

Bourgoin J.-P.,University of Waterloo | Meyer-Scott E.,University of Waterloo | Higgins B.L.,University of Waterloo | Helou B.,University of Waterloo | And 8 more authors.
New Journal of Physics | Year: 2013

Optical quantum communication utilizing satellite platforms has the potential to extend the reach of quantum key distribution (QKD) from terrestrial limits of ∼200 km to global scales. We have developed a thorough numerical simulation using realistic simulated orbits and incorporating the effects of pointing error, diffraction, atmosphere and telescope design, to obtain estimates of the loss and background noise which a satellite-based system would experience. Combining with quantum optics simulations of sources and detection, we determine the length of secure key for QKD, as well as entanglement visibility and achievable distances for fundamental experiments. We analyse the performance of a low Earth orbit satellite for downlink and uplink scenarios of the quantum optical signals. We argue that the advantages of locating the quantum source on the ground justify a greater scientific interest in an uplink as compared to a downlink. An uplink with a ground transmitter of at least 25 cm diameter and a 30 cm receiver telescope on the satellite could be used to successfully perform QKD multiple times per week with either an entangled photon source or with a weak coherent pulse source, as well as perform long-distance Bell tests and quantum teleportation. Our model helps to resolve important design considerations such as operating wavelength, type and specifications of sources and detectors, telescope designs, specific orbits and ground station locations, in view of anticipated overall system performance. © IOP Publishing and Deutsche Physikalische Gesellschaft.


Roy N.,COM DEV Canada | McCormick G.,University of Toledo | Devabhaktuni V.,University of Toledo | Raut R.,Concordia University at Montréal
Journal of Circuits, Systems and Computers | Year: 2010

Low-noise amplifiers (LNAs) are critical to a wide variety of electronic circuits. In the design phase preceding fabrication, an LNA needs to be designed for a given set of specifications (e.g., gain, noise-figure, power consumption, etc.), which tend to be application-dependent. Typically, LNA design using commercial computer-aided design (CAD) tools can be human-intensive and requires a certain degree of expertise. This paper presents a systematic multi-phase CAD approach for the design of LNAs. In the first phase, a quick pre-analysis of the given LNA specifications is carried out leading to the selection of an appropriate LNA topology. In the second phase, an initial design of the LNA is generated employing an appropriate design procedure. Finally, the initial design is adjusted/fine-tuned so as to meet/exceed the given specifications, where necessary. The advantages of the proposed approach are shown through several practical LNA design examples in 0.18 μm CMOS technology. © 2010 World Scientific Publishing Company.


Aase J.G.,University of Calgary | Burchill J.K.,University of Calgary | Knudsen D.,University of Calgary | Hackett J.P.,COM DEV Canada | Moffat B.,COM DEV Canada
Optical Engineering | Year: 2011

A detector consisting of two biased microchannel plates and a P20 or P43 phosphor screen was illuminated with 500-eV electrons in order to characterize the size and amplitude of individual microchannel plate (MCP) firings as a function of phosphor-to-MCP distance d and voltage Vacc. The P43 phosphor was significantly brighter (71%) than P20 at Vacc = 4250 V, and brighter but less so (4%) at Vacc = 8000 V. Events were Gaussian-shaped with full widths at half maximum of order 0.27 mm for V acc = 4250 V and d = 2 mm. Widths decreased by 23% to 28% when V acc was increased to 8000 V, and increased between 9 to 34% when doubling d, depending on Vacc and phosphor type. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).


Raut R.,Concordia University at Montréal | Devabhaktuni V.,University of Toledo | Roy N.,COM DEV Canada
Journal of Circuits, Systems and Computers | Year: 2010

In this paper, we present a fast and simple SPICE-based technique for the performance characterization of BJT mixers. First, exploiting fundamental concepts, an AC equivalent circuit of a radio-frequency bipolar junction transistor mixer is derived. Second, this equivalent circuit is used to estimate the conversion gain, noise-figure, and nonlinearity characteristics of the mixer. The proposed technique has been validated using simulations on integrated and discrete transistor based mixer circuits. © 2010 World Scientific Publishing Company.


Delamer S.,COM DEV Canada | Beaton S.,COM DEV Canada | Aldridge D.,COM DEV Canada | Klimas P.,COM DEV Canada | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The development of the James Webb Space Telescope (JWST) is an international collaboration led by NASA in partnership with the European Space Agency and the Canadian Space Agency (CSA). The Canadian contribution to the mission is the Fine Guidance Sensor (FGS). The FGS-Guider images two fields of view onto two detectors. For testing, Optical Ground Support Equipment telescopes are used to simulate the image from the Observatory's Optical Telescope Element. The FGS Engineering Test Unit (ETU) comprises 2 functioning Guider channels: one fully functional channel with a Teledyne H2RG HgCdTe 5 micron cutoff detector, and another with an H2RG multiplexer in place of a detector. This paper reports on the results of cryogenic vacuum testing of the alignment of the final ETU instrument configuration. Images at ambient (from the H2RG multiplexer) and at cryo (from detector and H2RG multiplexer) were analysed to determine best focus and FGS field of view at cryogenic temperatures. The ETU test results for best focus, tip/tilt of focal planes, field of view location and size are well matched to the budgets and predictions and meet requirements for the FGS-Guider. © 2010 SPIE.


Haley C.S.,COM DEV Canada | Evans C.,COM DEV Canada | Grant E.,COM DEV Canada | Norman R.,COM DEV Canada | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

The Fine Guidance Sensor (FGS) on the James Webb Space Telescope (JWST) has a science observing capability provided by the Tunable Filter Imager (TFI). The TFI incorporates dielectric coated Fabry-Perot etalon plates with a small vacuum gap. The separation of the plates is controlled by the Etalon Control Electronics (ECE) board, using piezoelectric actuators (PZTs) and capacitive displacement sensors (CDS). The TFI measures over the wavelength range of 1.6 to 4.9 microns with a spectral resolution of R∼100. We present the key components of the etalon system and the approach for characterizing and testing the system. Initial results from assembly-level testing are also presented. © 2010 SPIE.


Haley C.,COM DEV Canada | Roy N.,COM DEV Canada | Osman Z.,COM DEV Canada | Rowlands N.,COM DEV Canada | Scott A.,COM DEV Canada
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

The Fine Guidance Sensor (FGS) on the James Webb Space Telescope (JWST) has a science observing capability that was to be provided by a tunable Fabry-Pérot etalon incorporating dielectric coated etalon plates with a small vacuum gap and piezoelectric actuators (PZTs). The JWST etalon was more challenging than existing ground-based operational systems due to the low-order gap, the extremely wide waveband and the environmental specifications. Difficulties were encountered in providing the required performance due to variability in the mechanical gap after exposure to the vibration, shock and cryogenic cycling environments required for the JWST mission. The risks associated with operating the flight model etalon in the space environment, along with changes in scientific priorities, resulted in the etalon being replaced by the grism-based Near-Infrared Imager and Slitless Spectrograph (NIRISS). We describe here the performance of the etalon system and the unresolved risks that contributed to the decision to change the flight instrument. © 2012 SPIE.


Ingraham P.,University of Montréal | Doyon R.,University of Montréal | Beaulieu M.,University of Montréal | Rowlands N.,COM DEV Canada | Scott A.,COM DEV Canada
Publications of the Astronomical Society of the Pacific | Year: 2011

The scanning capability of a tunable filter represents an attractive option for performing high-contrast imaging through spectral differential imaging (SDI), a speckle-suppression technique widely used by current ground based high-contrast imaging instruments. The performance of such a tunable filter is illustrated through the Tunable Filter Imager (TFI), which used to be part of the science instrument complement of the James Webb Space Telescope (JWST). The TFI features a low-order Fabry-Perot etalon that enables imaging spectroscopy at an average resolving power of 100. Also included is a high-contrast imaging mode featuring a Lyot coronagraph aided by spectral differential imaging(SDI).Using a TFI prototype etalon, we demonstrate the calibration technique to be used in the parallelization of the etalons reflective plates and then evaluate the etalon's ability to perform speckle suppression through SDI. The improvement in contrast ranges from a factor of ~10 at working angles greater than 11λ=D, increasing up to a factor of ~60 at 5λ=D. These results are consistent with a Fresnel optical propagation model, which we use to show that the contrast improvement is limited by the test bed, and not the etalon. Our results demonstrate that a tunable filter such as the JWST TFI is an attractive solution for performing speckle suppression in space through multi-wave length imaging. © 2011. The Astronomical Society of the Pacific. All rights reserved.


Bender A.N.,McGill University | Cliche J.-F.,McGill University | De Haan T.,McGill University | Dobbs M.A.,McGill University | And 7 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

Frequency domain multiplexing (fMux) is an established technique for the readout of transition-edge sensor (TES) bolometers in millimeter-wavelength astrophysical instrumentation. In fMux, the signals from multiple detectors are read out on a single pair of wires reducing the total cryogenic thermal loading as well as the cold component complexity and cost of a system. The current digital fMux system, in use by POLARBEAR, EBEX, and the South Pole Telescope, is limited to a multiplexing factor of 16 by the dynamic range of the Superconducting Quantum Interference Device pre-amplifier and the total system bandwidth. Increased multiplexing is key for the next generation of large format TES cameras, such as SPT-3G and POLARBEAR2, which plan to have on the of order 15,000 detectors. Here, we present the next generation fMux readout, focusing on the warm electronics. In this system, the multiplexing factor increases to 64 channels per module (2 wires) while maintaining low noise levels and detector stability. This is achieved by increasing the system bandwidth, reducing the dynamic range requirements though active feedback, and digital synthesis of voltage biases with a novel polyphase filter algorithm. In addition, a version of the new fMux readout includes features such as low power consumption and radiation-hard components making it viable for future space-based millimeter telescopes such as the LiteBIRD satellite. © 2014 SPIE.

Loading COM DEV Canada collaborators
Loading COM DEV Canada collaborators