Insertion Loss Research Papers - Academia.edu (original) (raw)

2010, IEEE Journal of Selected Topics in Quantum Electronics

We give an overview of recent progress in passive spectral filters and demultiplexers based on silicon-on-insulator photonic wire waveguides: ring resonators, interferometers, arrayed waveguide gratings, and echelle diffraction gratings, all benefit from the high-index contrast possible with silicon photonics. We show how the current generation of devices has improved crosstalk levels, insertion loss, and uniformity due to an improved fabrication process based on 193 nm lithography.

2004, IEEE Microwave Magazine

Abstract: An IC engine is a major source of noise pollution, where exhaust noise play major contribution. That is why the reduction of exhaust noise from engines is an important issue. A muffler in the exhaust pipe is used for reducing noise. Muffler requires specific design considering various noise parameters. In this the tunable resonator is used whose length can be varied by using a piston that can be set at different positions. Noise level is also measured at the different positions of resonator to check the effect of variation of length of silencer that shows the smaller the resonator size better is insertion loss. A muffler for stationary petrol engine (engine test rig) has been designed. Sound level is measured before and muffler installation at different position of resonator piston & the effect of resonator length is studied.

Mufflers are important part of engine system and commonly used in exhaust system to minimize sound transmissions caused by exhaust gases. Design of mufflers is a complex function that affects noise characteristics, emission and fuel efficiency of engine. Therefore muffler design becomes more and more important for noise reduction. Traditionally, muffler design has been an iterative process by trial and error. However, the theories and science that has undergone development in recent years has given a way for an engineer to cut short number of iteration. This paper discusses the various functional requirements of automotive muffler like Insertion loss, Size of muffler, Backpressure, Cost and Weight. The objective of this study is to give general design guidelines for designing various parameters of muffler. This paper suggests suitable guidelines for selection of muffler grade, muffler length and diameter, Tail-pipe length according to engine cubic capacity and calculation of pressure drop in muffler on the basis of exhaust gas flow rate. It also explains the checking criteria for suitability of muffler for particular application.

2000, IEEE Transactions on Microwave Theory and Techniques

This paper reviews recent research conducted at the University of Toronto on the development of CMOS transceivers aimed at operation in the 90-170-GHz range. Unique nanoscale CMOS issues related to millimeter-wave circuit design in the 65-nm node and beyond are addressed with an emphasis on transistor and top-level layout issues, low-voltage circuit topologies, and design flow. A Doppler transceiver and two receivers fabricated in a 65-nm GPLP CMOS technology are described, along with a single pole, double throw antenna switch with better than 5-dB insertion loss and 25-dB isolation in the entire 110-170-GHz band. The first receiver has an IQ architecture with a fundamental frequency voltage-controlled oscillator, and is intended for wideband passive imaging applications at 100 GHz. The measured noise figure and downconversion gain are 7-8 and 10.5 dB, respectively, while the 3-dB bandwidth extends from 85 to 100 GHz. The second receiver has double-sideband architecture, operates in the 135-145-GHz range (the highest for CMOS receivers), and features an 8-dB gain LNA, a double-balanced Gilbert cell mixer, and a dipole antenna. The 90-94-GHz Doppler transceiver, the highest frequency reported to date in CMOS, is intended for the remote monitoring of respiratory functions. A Doppler shift of 30 Hz, produced by a slow-moving (4.8 cm/s) target located at a distance of 1 m, was measured with a transmitter output power of approximately +2 dBm and a phase noise of 90 dBc/Hz at 1 MHz offset. The range correlation effect is demonstrated for the first time in CMOS by measuring the phase noise of the received baseband signal at 10-Hz offset, clearly indicating that 1 noise has been canceled and it does not pose a problem in short-range applications, where neither a phase-locked loop nor a frequency divider are needed.

This paper examines the effect of the geometrical shapes of a defected ground-plane structure (DGS) slot on performance of the Hi-Lo microstrip low-pass filter (LPF). A three-pole LPF based on an arrowhead DGS slot has 67% less length as compared to a conventional three-pole LPF. It has insertion loss of 0.5 dB and 15-dB rejection in the stopband up to three times the cutoff frequency. Index Terms-Defected ground-plane structure (DGS) slot, low-pass filter (LPF), microstrip filter, slot in ground plane. A. S. Omar (M'87-SM'89) received the B.Sc. and M.Sc. degrees from Ain Shams University, Cairo, Egypt, in 1978 and 1982, respectively, and the Doktor-Ing. degree in electrical engineering from the

2009, Journal of Electromagnetic Waves and Applications

1999, Materials Science in Semiconductor Processing

ZnO is a wide bandgap semiconductor material with high piezoelectric coupling coecients. It can be used for making low-loss surface acoustic wave (SAW) ®lters operating at high frequency. We report MOCVD growth of epitaxial ZnO thin ®lms on R-plane sapphire substrates. The crystallinity and orientation of the ®lms, as well as the epitaxial relationship between the ZnO ®lms and the R-plane Al 2 O 3 substrate were studied using X-ray diraction techniques. An atomically sharp interface structure was revealed by high-resolution TEM. Surface morphology was investigated using ®eld emission SEM. SAW ®lters with 10 and 16 mm wavelength were fabricated. Low insertion loss and high piezoelectric coupling coecient, up to 6%, were achieved. The acoustic velocities range from 4050 to 5800 m/s, varying as a function of ZnO ®lm thickness. #

2004

Power filter manufacturers provide Insertion Loss (IL) measurement data for their products. These are usually 50 Ω / 50 Ω and sometimes the so-called "approximate worst case measurements". The aim of this work is to find out which of these data should be considered when selecting an input filter for a switched mode power supply. The results show that, the actual common mode attenuation of a filter operating with a buck converter is almost same as the IL data with 0.1 Ω / 100 Ω source and load impedance, whereas the actual differential mode IL is approximately same as the IL data for 100 Ω / 0.1 Ω conditions.

In this research, a concurrent quadband bandpass filter (BPF) for mobile broadband wireless access (m-WBWA) is designed and evaluated by using Advanced Design System (ADS). The frequency center of BPF can be operated at four specific frequencies of m-BWA which are 950 MHz and 1.85 GHz for GSM, 2.35 GHz for WiMAX, and 2.65 GHz for LTE concurrently. The BPF circuit is designed and fabricated with lumped element consists of inductor (L) and capacitor (C). The design of filter must satisfy to some requirement such as input return loss (S11) < -10 dB, insertion loss (S21) > -3 dB, bandwidth S21 of 50 MHz on center frequency 950 MHz and 100 MHz on center frequencies 1.85 GHz, 2.35 GHz, and 2.65 GHz, VSWR between 1 -2 with group delay less than 10 ns. It is shown from the results that designed filter had satisfied to the parameter standard. However, the fabricated results S11, S21, and VSWR are not satisfied to the design requirement. The operating frequencies of the fabricated quadband BPF are shifted, in average to 5 -10 MHz lead to simulation results. The simulated and fabricated filter on group delay also shown a difference but the value is still less than 10 ns.

2000, IEEE Transactions on Microwave Theory and Techniques

A tunable third-order combline bandpass filter using thin-film barium-strontium-titanate varactors and fabricated on a sapphire substrate is reported. Application of 0-200-V bias varied the center frequency of the filter from 2.44 to 2.88 GHz (16% tuning) while achieving a 1-dB bandwidth of 400 MHz. The insertion loss varied from 5.1 dB at zero bias to 3.3 dB at full bias, while the return loss exceeded 13 dB over the range. The third-order intercept of the filter was found to be 41 dBm.

In the 21st century, automobile industries are increasing at an unimaginable space. A huge problem of internal combustion (IC) engines is that it is a main cause of noise pollution. That is the reason mufflers are used to reduce the noise produced. Though mufflers are not designed to serve any primary exhaust function, they are installed within the exhaust system of most IC engines. It is designed as a soundproofing device that reduces the loudness of the pressure created by the engine. But mufflers need design and geometry considering the physics behind it which is very confounded. Established muffler design has been an iterative process by trial and error method. With recent research in this area has made it possible to do it in an analytical and experimental way.
There are two types of muffler, absorption type muffler and reactive muffler. The project dealt with the complexity behind the different mufflers and finally designed and constructed an absorption type muffler. After constructing the muffler according to our design using mild steel sheet and steel wool, we compared its performance based on three cases, no muffler condition, laboratory muffler condition and our newly designed muffler condition. Each case we calculated the insertion loss, brake specific fuel consumption (BSFC) and specific fuel consumption (SFC). And finally we showed with graphical representation that, our designed muffler performed better than the laboratory muffler condition and no muffler condition.
Of course, we did not achieve our desired result, since mild steel is no longer used as the construction material anymore and the available steel wool was not quality as we expected. However, we hope using better construction material and our design will certainly reduce the sound pressure level a great deal.

2007, IEEE Microwave and Wireless Components Letters

A novel leaky-wave antenna is demonstrated and developed at Ka-band in this work based on the newly proposed half-mode substrate integrated waveguide (HWSIW). This antenna is accurately simulated by using a full-wave electromagnetic simulator and then fabricated through a single-layer printed circuit board (PCB) process. Wide bandwidth and a quasi-omnidirectional radiation pattern are obtained. The proposed antenna is therefore a good candidate for millimeter-wave applications. Measured results are in good agreement with simulated results. Index Terms-Half-mode substrate integrated waveguide (HMSIW), leaky-wave antenna (LWA), millimeter-wave antenna, quasi-omnidirectional radiation pattern.

2000, IEEE Transactions on Advanced Packaging

A transition from coplanar waveguide (CPW)-tomicrostrip with vias is often used in wafer-probe measurements. This paper shows how field and impedance matching are used to develop a wideband transition. This paper demonstrates how the presence and placement of the vias affect the bandwidth and alters the impedance of the transition. The measured results on a transition show that a wideband transition with return loss better than 10 dB and an insertion loss less than 1.5 dB up to 36.64 GHz is obtained. The measurements show excellent agreement with simulation. The work presented in this paper provides a better understanding about a CPW-to-microstrip transition with vias as well as design procedures and principles that can be utilized to facilitate the realization of a broadband CPW-to-microstrip transition with vias.

2008, Progress In Electromagnetics Research

We present here a new pattern with compact size of Ultra Wideband (UWB) microwave filter. The filter is based on quarter-wave length short-circuited stubs model. We introduced here a new schematic model by extracting all parasitic elements such as Tjunction and discontinuity in our new pattern of UWB filter. This new filter has minimal number of vias and improved frequency bandwidth, insertion loss and return loss. It is fabricated on RT Duroid 5880 with 0.508 mm of substrate thickness. The final dimension is measured as 21 mm × 14 mm. It is not only compact, but also delivers excellent scattering parameters with magnitude of insertion loss, |S 21 | lower than 0.85 dB and return loss better than −11.6 dB. The fractional bandwidth is 109% from 3.06 GHz to 10.43 GHz. In the pass band, the measured group delay varies in between 0.47 ns to 0.32 ns, showing stability with minimum variation of only 0.15 ns. † The first author is also with School of Computer and Communication Engineering,

1999, Electrical Engineering

Electrical Engineering 8i (i999) 4z9-424 9 Springer-Verlag i999 kegendre polynomials Contents Filters derived from Legendre polynomials and products of them are presented using the insertion-loss method. These have properties that lie between those based on the Butterworth and Chebyshev polynomials. Tables of element values for low-pass filter prototypes and curves of attenuation versus normalised frequency are given for design purposes. The extension of the results by frequency transformation to other types of filters is shown by designing a band-pass filter at 1.6 GHz.

1997, IEEE Transactions on Microwave Theory and Techniques

Ferroelectric materials (FEM's) are very attractive because their dielectric constant can be modulated under the effect of an externally applied electric field perpendicular to the direction of propagation of a microwave signal. FEM may be particularly useful for the development of a new family of planar phase shifters which operate up to X X X-band. The use of FEM in the microwave frequency range has been limited in the past due to the high losses of these materials tan = 0:3 at 3 GHz is typical for commercial BaTiO 3 (BTO) and due to the high electric field necessary to bias the structure in order to obtain substantial dielectric constant change. In this paper, how a significant reduction in material losses is possible is demonstrated. This is achieved by using a new sol-gel technique [1] to produce barium modified strontium titanium oxide [Ba10xSrxTiO3 (BST)], which has ferroelectric properties at room temperature. Also demonstrated is how the use of thin ceramics reduces the required bias voltage below 250 V, with almost no power consumption required to induce a change in the dielectric constant. A phase shift of 165 was obtained at 2.4 GHz, with an insertion loss below 3 dB by using a bias voltage of 250 V. Due to the planar geometry and light weight of the device, it can be fully integrated in planar microwave structures.

2005, Applied Acoustics

The paper describes an investigation about the acoustic performance of noise barriers with quadratic residue diffuser (QRD) tops, and with T-, Arrow-, Cylindrical and Y-shape profiles. A 2D Boundary Element Method (BEM) is used to calculate the barrier insertion loss. The results of rigid and with absorptive coverage are also calculated for comparisons.

1981, IEEE Transactions on Magnetics

The dc magnetic field dependence of rf permeability in ferrite, the deviations of resonance dc magnetic field and its half-width in a ferrite disk, and the destruction temperature difference of the ferrite disks are measured in order to select the ferrite material and disk for high-power microwave circulator. Also demonstrated are the design and performance of a newly developed multi-layered junction circulator with a power handling capability of CW 250 KW at 500 MHz band.

1991, Microwave and …

This paper describes a new approach for the realization of tunable/variable 111-V planar microwave integrated circuits, which employs micromachined electrostatically con-trolEd actuator technology. This technology is potentially compatible with conventional MMIC fabrication techniques, and allows precise positioning and re-positioning of metal conductors (tuning stubs, switches, capacitor plates, etc.) on an insulating substrate after fabrication is complete. % A variety of structures have been fabricated, including electrostatic micro-motors, rotating microwave switches, and variable interdigitated capacitors. A rotating microwave transmission line switch exhibited less than 0.5 dB insertion loss and greater than 35 dB isolation from dc to 45 GHz. A variable interdigitated capacitor exhibited a variation from 35 fF t+~ 100 fF. A number of aspects of the technology require further research, including improvement in starting voltages, repeatability of contacts, and microwave design.

2000, IEEE Transactions on Magnetics

We have designed and simulated a circulator circuit in which the magnetization aligns along the plane of an yttrium iron garnet (YIG) film. For an X-band frequency (8-12 GHz) circulator we have utilized a YIG slab ( 200 m thick) with saturation magnetization (4 ) and ferrimagnetic resonance (FMR) linewidth (1 ) of 139.26 kA/m and 10 Oe, respectively. Broadband circulator operation was realized for frequencies above FMR, = 5 GHz. The applied FMR field was 79.58 kA/m. The Ansoft HFSS software suite was used to simulate the circulator response. The insertion loss 21 and the isolation 12 were calculated to be 0.9 dB and 52 dB, respectively, with 15% bandwidth at the center frequency of 10.1 GHz. We believe that this in-plane circulator design may enable high performance with significant volume and weight reduction.

2010, IEEE/ASME Journal of Microelectromechanical Systems

This paper describes a bulk-micromachined electrostatically tunable Fabry-Perot interferometric filter. The device is a hybrid optical filter combining fiber optics and microelectromechanical systems (MEMS) technologies. The static mirror is a Bragg grating mirror built on the end face of an optical fiber that is integrated with a MEMS device, which includes the tunable gold-coated mirror. The MEMS device is fabricated in 100 -oriented silicon wafers using modified and optimized batch MEMS processes. A two-stage approach was used to achieve high finesse (F) and broad tunability simultaneously. In the first stage, actuator issues and mirror structural defects were corrected for by optimizing the fabrication-process parameters. In this stage, near-theoretical performance has been achieved with a pure Si MEMS tunable etalon. In stage two, optical fibers with dielectric stack mirrors from Micron Optics, Inc. have been integrated with the MEMS devices to form tunable cavities. The device insertion loss was below 15 dB and was mostly attributed to absorption losses in the gold coating. We measured a pass bandwidth of around 0.54 nm and a tuning range of nearly 120 nm resulting in an F of over 220.

2008, Applied Acoustics

A previous paper [Applied Acoustics 66, pp.709-730, 2005] has shown that adding a quadratic residue diffuser (QRD) to the top of a T-shape barrier can provide better barrier performance than an equivalent purely absorptive barrier. In here, we extend the study to look at the performance when a QRD is made absorptive. This paper presents an investigation on the acoustic performance of a few welled-diffusers with different absorption ability on top of a T-shape noise barrier. The absorption properties of the diffusers are modified with different sequences, by filling the wells with fiberglass, by covering the well entrance with wire meshes, and by putting perforated sheet either on the top surface or inside the wells. A 2D Boundary Element Method (BEM) is used to calculate the barrier insertion loss. The numerical and experimental results on diffuser barriers with rigid and absorptive covers are compared. Among the tested models the best method of treating diffuser barriers with absorbent agents in the QRD is found to be a perorated sheet on top or inside the diffuser wells. It is found that increasing the absorption ability of QRD by fiberglass or high resistance wire meshes has negative effect on the efficiency of a QRD barrier. It is shown that, if the increase in absorption destroys the effect of resonance in wells, it will also have negative effect on the insertion loss performance of the QRD edge barrier.

2000, Optimization Letters

The design and characterization of ring-resonator-based filters with free spectral ranges of 100 and 50 GHz by use of SiO x N y technology is presented. Fiber-to-fiber insertion losses of 4.4 dB on the drop port and 2.1 dB on the through port have been achieved for a single-ring filter. An interleaver filter for a 25-GHz spaced dense wavelength-division multiplexing system with two cascaded rings is demonstrated. The filter has a 7.4-GHz bandwidth at 21 dB and an extinction ratio of 15 dB and is polarization independent.

2011, 2011 Loughborough Antennas & Propagation Conference

This paper presents a novel one-to-eight compact feeding network based on the Wilkinson power divider for a circular antenna array. The network consists of four 1:2 conventional Wilkinson power dividers. The outputs revolve at 45° in order to satisfy the circular geometry on an FR-4 substrate. Moreover, the network size has been optimized and miniaturized targeting compact portable devices. The feeding network design targets WiFi and LTE/4G frequency bands. Designed and examined with the CST Microwave Studio, this feeding network provides suitable return loss, insertion loss and isolation parameters for the designated frequency ranges. Fabrication and measurement results closely correlate with simulation results. The design can be applied to SIMO and MIMO microwave systems.

2007, Optics and lasers in …

2009, 2009 IEEE Antennas and Propagation Society International Symposium

2000, IEEE Microwave and Wireless Components Letters

We demonstrate a compact, linear, and low loss variation hybrid phase shifter using a left-handed (LH) transmission line. For frequencies from 4.3 to 5.6 GHz, this phase shifter gives a nearly linear phase variation with voltage, with a maximum deviation of 7 5 . Within this frequency range, the maximum insertion loss is 3.6 dB, and the minimum insertion loss is 1.8 dB over a continuously adjustable phase range of more than 125 , while minimum return loss is only 10.2 dB. Furthermore, this phase shifter requires only one control line, and it consumes almost no power.

2004, Sensors, 2004. …

Design of a CMOS compatible thin ZnO film base, and a LiNbO3 wafer base, Surface Acoustics Wave (SAW) gas sensors that are highly selective and sensitive are described. Furthermore, Design an post CMOS processing fabrication steps that utilizes micro-electro-mechanical systems (MEMS) techniques to implement SAW gas sensor is presented. Rayleigh wave velocity for various ZnO film thickness is simulated and results are presented. Velocity calculation is based on a computer simulation of multiplayer (ZnO/SiO 2 /Si) structure that uses wave equations. Simulation results and experimental measurements of SAW sensors with single layer bulk LiNbO3 wafer are shown, and compared. Moreover, results of experimentation and simulation of wave velocity for a yz-cut LiNbO3 wafer is shown.

2008, 2008 European Microwave Integrated Circuit Conference

In this paper the design, fabrication and test of X-Band and 2-18GHz wideband high power SPDT MMIC switches in microstrip GaN technology are presented. Such switches have demonstrated state-of-the-art performances. In particular the X-Band switch exhibits 1dB insertion loss, better than 37dB isolation and a power handling capability at 9 GHz of better than 39dBm at 1dB insertion loss compression point; the wideband switch has an insertion loss lower than 2.2dB, better than 25dB isolation and a power handling capability of better than 38dBm in the entire bandwidth.

A W-band direct-detection-based receiver front-end for millimeter-wave passive imaging in a 0.18m BiCMOS process is presented. The proposed system is comprised of a direct-detection front-end architecture employing a balanced LNA with an embedded Dicke switch, power detector, and baseband circuitry. The use of a balanced LNA with an embedded Dicke switch minimizes front-end noise figure, resulting in a great imaging resolution. The receiver chip achieves a measured responsivity of 20-43 MV/W with a front-end 3-dB bandwidth of 26 GHz, while consuming 200 mW. The calculated NETD of the SiGe receiver chip is 0.4 K with a 30 ms integration time. This work demonstrates the possibility of silicon-based system-on-chip solutions as lower cost alternatives to compound semiconductor multi-chip imaging modules.

2011, Applied Acoustics

This article describes an objective methodology for measuring the noise attenuation of earmuff hearing protectors using as a reference the method known as microphone-in-real-ear (MIRE). The methodology implements the insertion loss (IL) paradigm, in which IL is measured using miniature microphones, specially designed to comply with ANSI and ISO standards for the MIRE technique. The results for four different hearing protectors are compared with the subjective method known as real-ear-attenuation-atthreshold (REAT). Correction factors are included in the methodology to account for external effects such as physiological noise and bone conduction. The objective method predicted well the real protection of the earmuffs and the proposed methodology showed lower standard deviation values than the REAT method.

2012, … and Frequency Control, …

This paper reports on the design, fabrication, and characterization of a small form factor, piezoelectrically transduced, tunable micromechanical resonator for real-time clock (RTC) applications (32.768 kHz). The device was designed to resonate in an out-of-plane flexural mode to simultaneously achieve low-frequency operation and reduced motional resistance in a small die area. Finite element simulations were extensively used to optimize the structure in terms of size, insertion loss, spurious-mode rejection, and frequency tuning. Microresonators with an overall die area of only 350 × 350 µm were implemented on a thin-film AlN on silicon-on-insulator (SOI) substrate with AlN thickness of 0.5 µm, device layer of 1.5 µm, and an electrostatic tuning gap size of 1 µm. A frequency tuning range of 3100 ppm was measured using dc voltages of less than 4 V. This range is sufficient to compensate for frequency variations of the microresonator across temperature from −20°C to 100°C. The device exhibits low motional impedance that is completely independent of the frequency tuning potential. Discrete electronics were used in conjunction with the resonator to implement an oscillator, verifying its function

1996, Ultrasonics, Ferroelectrics and …

2006, IEEE Transactions on Microwave Theory and Techniques

This paper presents a compact system-on-package-based front-end solution for 60-GHz-band wireless communication/sensor applications that consists of fully integrated three-dimensional (3-D) cavity filters/duplexers and antenna. The presented concept is applied to the design, fabrication, and testing of V-band (receiver (Rx): 59-61.5 GHz, transmitter (Tx): 61.5-64 GHz) transceiver front-end module using multilayer low-temperature co-fired ceramic technology. Vertically stacked 3-D low-loss cavity bandpass

2009, Proceedings of the Ieee

Experimental results have demonstrated the feasibility of the kind of high-speed, efficient optical modulators that are needed for optical interconnection devices. ABSTRACT | The evolution of silicon optical modulators is recalled, from the first effect demonstrations to the characterization of high-performance devices integrated in optical waveguides. Among possibilities to achieve optical modulation in silicon-based materials, the carrier depletion effect has demonstrated good capacities. Carrier depletion in Si and SiGe/ Si structures has been theoretically and experimentally investigated. Large phase modulation efficiency, low optical loss, and large cutoff frequency are obtained by considering simultaneously optical and electrical structure performances. Integrated Mach-Zehnder interferometers and resonators are compared to convert phase modulation into intensity modulation. Finally, recent results on high-speed and low-loss silicon optical modulator using an asymmetric Mach-Zehnder interferometer are presented. It is based on a p-doped slit embedded in the intrinsic region of a lateral pin diode integrated in a silicon-on-insulator waveguide. This design allows a good overlap between the optical mode and carrier density variations. An insertion loss of 5 dB has been measured with a À3 dB bandwidth of 15 GHz.

2000, IEEE Transactions on Microwave Theory and Techniques

We will demonstrate an alternative topology for the feedforward amplifier. This amplifier does not use a delay element, thus providing an efficiency enhancement and a size reduction by employing a distributed-element negative group-delay circuit. The insertion loss of the delay element in the conventional feedforward amplifier seriously degrades the efficiency. Usually, a high-power coaxial cable or a delay-line filter is utilized for a low loss, but the insertion loss, cost, and size of the delay element still act as a bottleneck. The proposed negative group-delay circuit removes the necessity of the delay element required for a broadband signal suppression loop. With the fabricated two-stage distributed-element negative group-delay circuit with 30 MHz of bandwidth and 9 ns of group delay for a wideband code-division multiple-access downlink band, the feedforward amplifier with the proposed topology experimentally achieved 19.4% power-added efficiency and 53.2-dBc adjacent channel leakage ratio with 44-dBm average output power.

2016

Entrevue avec Marie-Jeanne Blain, candidate au doctorat, anthropologie, Université de Montréal (Sous la direction de Sylvie Fortin, chercheure METISS et professeure, Département d’anthropologie, Université de Montréal et la codirection de... more

Entrevue avec Marie-Jeanne Blain, candidate au doctorat, anthropologie, Université de Montréal
(Sous la direction de Sylvie Fortin, chercheure METISS et professeure, Département d’anthropologie, Université
de Montréal et la codirection de Fernando Alvarez, professeur, CHU Sainte-Justine et département de pédiatrie,
Université de Montréal)

1986, Optics Letters

An all-fiber-optic frequency shifter is demonstrated that uses mode coupling between the LP 01 and LP 11 modes by a traveling acoustic flexural wave guided along the optical fiber. The input and output leads of this frequency shifter are single-mode fibers. Unity mode-conversion efficiency for cw operation is achieved at 8-MHz frequency shift with about 0.25 W of electrical input power. Carrier and image sideband suppression of 15 and 35 dB, respectively, are demonstrated. 0146-9592/86/060389-03$2.00/0

2009

This paper presents a new design of miniaturized wideband bandpass filter using microstrip hairpin in multilayer configuration for X-band application. The strong coupling required for wideband filter is realized by arranging five hairpin resonators in two layers on different dielectric substrates. Since adjacent resonator lines are placed at different levels, there are two possible ways to change coupling strength by varying the overlapping gap between two resonators; vertically and horizontally. In this paper, simulated and measured result for a wideband filter of 4.4 GHz bandwidth at 10.2 GHz center frequency with fifth order Chebyshev response is proposed. The filter is fabricated on 0.254 mm thickness R/T Duroid 6010 and R/T Duroid 5880 with dielectric constant 10.2 and 2.2 respectively using standard photolithography technique. Two filter configurations based on vertical (Type 1) and horizontal (Type 2) coupling variation to optimize the coupling strength are presented and compared. Both configurations produce very small and compact filter size, at 5.0 × 14.6 mm 2 and 3.2 × 16.1 mm 2 for the first and second proposed filter type respectively. The measured passband insertion losses for both filters are less than 2.3 dB and the passband return loss is better than −16 dB for filter Type 1 and −13 dB for filter Type 2. Very small and compact filter is achieved where measured results show good agreement with the simulated responses.

2004, IEEE Photonics Technology Letters

Silica planar waveguide echelle grating demultiplexers with 48 channels and 256 channels are described and demonstrated. Polarization effects due to stress birefringence and polarization-dependent grating efficiency have been eliminated using a modified polarization compensator and grating design. The devices have a polarization-dependent wavelength shift of less than 10 pm, and a polarization-dependent loss below 0.2 dB. The 48-channel device has a measured crosstalk of 35 dB, an insertion loss better than 4 dB, and a uniformity of 1 dB across the -band.

2003, The Journal of the Acoustical Society of America

A case is presented for the important role of cavitation in stone comminution and tissue injury in shock wave lithotripsy (SWL). Confocal hydrophones and a coincidence algorithm were used to detect cavitation in kidney parenchyma. Elevated hydrostatic pressure dissolved cavitation nuclei and suppressed cell injury and stone comminution in vitro. A low-insertionloss, thin, mylar film nearly eliminated stone erosion and crack formation only when in direct contact with the stone. This result indicates not only that cavitation is important in both cracking and erosion but also that bubbles act at the surface. Time inversion of the shock wave by use of a pressure-release reflector reduced the calculated pressure at bubble collapse and the measured depth of bubble-induced pits in aluminum. Correspondingly tissue injury in vivo was nearly eliminated. Cavitation was localized and intensified by the use of synchronously triggered, facing lithotripters. This dual pulse lithotripter enhanced comminution at its focus and reduced lysis in surrounding blood samples. Enhancement of comminution was lost when stones were placed in glycerol, which retarded bubble implosion.

2011

A tri-band dual-mode chip filter, which is fabricated in a commercial pHEMT GaAs technology and suitable for millimeter-wave applications, is presented in this paper. This filter is constructed by using stacked ring resonators with individual perturbations and feeding capacitors; thus, fractional bandwidths and center frequencies of three pass bands can be flexibly controlled. A model of the tri-band filter that considers coupling effects between stacked ring resonators is first proposed, and then a synthesis method that can determine values of all elements of a typical dual-mode ring filter based on specifications of required characteristics is also described. According to the proposed design method, filter designers can quickly determine the layout pattern of the tri-band dual-mode filter which employs proper metal-insulator-metal (MIM) capacitors to obtain the desired filter performance. To verify the proposed design concept, an experimental prototype, locating three pass bands at 60 GHz, 77 GHz and 100 GHz, respectively, was fabricated on GaAs substrate. The size of the filter is about 0.46×0.91 mm2 and the measured insertion losses in the three passbands are less than 2.4 dB, 2.7 dB and 3.5 dB. The associated return losses are greater 18 dB, 17 dB and 8 dB over the frequency bands of interest.

2000, IEEE Transactions on Microwave Theory and Techniques

A very compact planar fully integrated circulator operating at millimeter wavelength has been designed using a magnetic substrate combining a polymer membrane with an array of ferromagnetic nanowires. The original feature of this substrate, called magnetic nanowired substrate (MNWS), relies on the fact that the circulation effect is obtained without requiring any biasing dc magnetic field. This leads to a significant reduction of device dimensions since no magnetic field source is needed, and a realistic ability for integration with monolithic microwave integrated circuits. The circulator design is performed by an efficient analytical model including a self design of the impedance matching network. This model also allows a physical understanding of the circulation mechanism through the access to the electromagnetic field patterns inside the circulator substrate. Based on the excellent agreement between the theoretical and experimental results, the model is used to predict the improvement of circulator performances resulting from a reduction of dielectric and conductor losses. Insertion losses lower than 2 dB with an isolation higher than 45 dB are expected for MNWS circulators with a low-loss substrate and thick metallic layers.

2003

An electrostatically actuated broadband ohmic microswitch has been developed that has applications from DC through the microwave region. The microswitch is a 3terminal device based on a cantilever beam and is fabricated using an all-metal, surface micromachining process. It operates in a hermetic environment obtained through a waferbonding process. Characteristics of the wafer-level packaged switch include DC on-resistance of less than 1 Ohm with an actuation voltage of 80 V, lifetime of greater than 10 10 cycles with on-resistance variation of less than 0.2 Ohm and current handling capability of 1 Ampere. Key RF characteristics at 2 GHz include an insertion loss of 0.32 dB and isolation of 33 dB for our 4-contact microswitch. Preliminary measurements at higher microwave frequencies are extremely promising with full characterization and planned product improvements underway.

2000, IEEE Transactions on Magnetics

2008, IEEE Transactions on Microwave Theory and Techniques

This paper presents a new method of designing tightly coupled directional couplers on printed circuit board substrates. The coupler is realized by placing a piece of floating metal plate on parallel-coupled microstrip lines to enhance the coupling between the lines. This structure yields a tightly coupled directional coupler without wire bonding and using high-resolution fabrication processes. A design procedure based on closed-form design equations of the parallel-coupled microstrips is proposed to design the new coupler. An -band 3-dB coupler constructed from the new structure is fabricated and measured to verify the proposed design procedure. Another wideband coupler, comprising two sections of conventional microstrip couplers and one section of the new type coupler, is also fabricated and measured to demonstrate the flexibility of connecting the new structure and conventional microstrip structures or devices. The measurements of the two couplers demonstrate that the coupler operates properly with approximately 54% and 94% fractional bandwidth, respectively, showing good agreement with the electromagnetic simulations. Additionally, a broadband filter consisting of four sections of the proposed coupling structure is fabricated and tested. The measured insertion losses are around 0.8 dB associated with return losses of greater than 15 dB over a frequency range of 4.5-7.1 GHz, corresponding to a fractional bandwidth of 45%.