WorldWideScience

Sample records for amplifiers

  1. Operational amplifiers

    CERN Document Server

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  2. Low cost instrumentation amplifier

    Science.gov (United States)

    Sturman, J. C.

    1974-01-01

    Amplifier can be used for many applications requiring high input impedance and common mode rejection, low drift, and gain accuracy on order of one percent. Performance of inexpensive amplifier approaches that of some commercial instrumentation amplifiers in many specifications.

  3. Gain ranging amplifier

    International Nuclear Information System (INIS)

    A gain ranging amplifier system is provided for use in the acquisition of data. Voltage offset compensation is utilized to correct errors in the gain ranging amplifier system caused by thermal drift and temperature dependent voltage offsets, both of which are associated with amplifiers in the gain ranging amplifier system

  4. Amplified Quantum Transforms

    OpenAIRE

    Cornwell, David

    2014-01-01

    In this thesis we investigate two new Amplified Quantum Transforms. In particular we create and analyze the Amplified Quantum Fourier Transform (Amplified-QFT) and the Amplified-Haar Wavelet Transform. First, we provide a brief history of quantum mechanics and quantum computing. Second, we examine the Amplified-QFT in detail and compare it against the Quantum Fourier Transform (QFT) and Quantum Hidden Subgroup (QHS) algorithms for solving the Local Period Problem. We calculate the probabiliti...

  5. Portable musical instrument amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Christian, David E. (Danbury, CT)

    1990-07-24

    The present invention relates to a musical instrument amplifier which is particularly useful for electric guitars. The amplifier has a rigid body for housing both the electronic system for amplifying and processing signals from the guitar and the system's power supply. An input plug connected to and projecting from the body is electrically coupled to the signal amplifying and processing system. When the plug is inserted into an output jack for an electric guitar, the body is rigidly carried by the guitar, and the guitar is operatively connected to the electrical amplifying and signal processing system without use of a loose interconnection cable. The amplifier is provided with an output jack, into which headphones are plugged to receive amplified signals from the guitar. By eliminating the conventional interconnection cable, the amplifier of the present invention can be used by musicians with increased flexibility and greater freedom of movement.

  6. Amplifier for nuclear spectrometry

    International Nuclear Information System (INIS)

    The spectroscopy amplifier model AE-020 is designed to adjust suitable the pulses coming from nuclear radiation detectors. Due to is capacity and specifications, the amplifier can be used together with high and medium resolution spectroscopy system

  7. High voltage distributed amplifier

    Science.gov (United States)

    Willems, D.; Bahl, I.; Wirsing, K.

    1991-12-01

    A high-voltage distributed amplifier implemented in GaAs MMIC technology has demonstrated good circuit performance over at least two octave bandwidth. This technique allows for very broadband amplifier operation with good efficiency in satellite, active-aperture radar, and battery-powered systems. Also, by increasing the number of FETs, the amplifier can be designed to match different voltage rails. The circuit does require a small amount of additional chip size over conventional distributed amplifiers but does not require power dividers or additional matching networks. This circuit configuration should find great use in broadband power amplifier design.

  8. RF Power Amplifier Analysis

    OpenAIRE

    M. Lokay; K. Pelikan

    1993-01-01

    The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.

  9. Amplifier improvement circuit

    Science.gov (United States)

    Sturman, J.

    1968-01-01

    Stable input stage was designed for the use with a integrated circuit operational amplifier to provide improved performance as an instrumentation-type amplifier. The circuit provides high input impedance, stable gain, good common mode rejection, very low drift, and low output impedance.

  10. Semiconductor optical amplifiers

    CERN Document Server

    Dutta, Niloy K

    2013-01-01

    This invaluable look provides a comprehensive treatment of design and applications of semiconductor optical amplifiers (SOA). SOA is an important component for optical communication systems. It has applications as in-line amplifiers and as functional devices in evolving optical networks. The functional applications of SOAs were first studied in the early 1990's, since then the diversity and scope of such applications have been steadily growing. This is the second edition of a book on Semiconductor Optical Amplifiers first published in 2006 by the same authors. Several chapters and sections rep

  11. RF Power Amplifier Analysis

    Directory of Open Access Journals (Sweden)

    M. Lokay

    1993-04-01

    Full Text Available The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.

  12. Noise in Optical Amplifiers

    DEFF Research Database (Denmark)

    Jeppesen, Palle

    1997-01-01

    Noise in optical amplifiers is discussed on the basis of photons and electromagntic fields. Formulas for quantum noise from spontaneous emission, signal-spontaneous beat noise and spontaneous-spontaneous beat noise are derived.......Noise in optical amplifiers is discussed on the basis of photons and electromagntic fields. Formulas for quantum noise from spontaneous emission, signal-spontaneous beat noise and spontaneous-spontaneous beat noise are derived....

  13. Charge-sensitive amplifier

    OpenAIRE

    Startsev V. I.; Yampolsky Ju. S.

    2008-01-01

    The authors consider design and circuit design techniques of reduction of the influence of the pyroelectric effect on operation of the charge sensitive amplifiers. The presented experimental results confirm the validity of the measures taken to reduce the impact of pyroelectric currents. Pyroelectric currents are caused by the influence of the temperature gradient on the piezoelectric sensor and on the output voltage of charge sensitive amplifiers.

  14. E-537 MWPC amplifier

    International Nuclear Information System (INIS)

    The design of a fast MWPC amplifier for the beam chambers and the absorber chamber is completed and all parts are on order. A prototype 16 channel board has been built and satisfactorily tested. Artwork is completed for the board and out to be photographed. The board fabrication contract has been let. Listed below is a summary of the amplifier characteristics as well as test results obtained with the prototype

  15. Electrospun Amplified Fiber Optics

    OpenAIRE

    Morello, Giovanni; Camposeo, Andrea; Moffa, Maria; Pisignano, Dario

    2015-01-01

    A lot of research is focused on all-optical signal processing, aiming to obtain effective alternatives to existing data transmission platforms. Amplification of light in fiber optics, such as in Erbium-doped fiber amplifiers, is especially important for an efficient signal transmission. However, the complex fabrication methods, involving high-temperature processes performed in highly pure environment, slow down the fabrication and make amplified components expensive with respect to an ideal, ...

  16. A micropower electrocardiogram amplifier.

    Science.gov (United States)

    Fay, L; Misra, V; Sarpeshkar, R

    2009-10-01

    We introduce an electrocardiogram (EKG) preamplifier with a power consumption of 2.8 muW, 8.1 muVrms input-referred noise, and a common-mode rejection ratio of 90 dB. Compared to previously reported work, this amplifier represents a significant reduction in power with little compromise in signal quality. The improvement in performance may be attributed to many optimizations throughout the design including the use of subthreshold transistor operation to improve noise efficiency, gain-setting capacitors versus resistors, half-rail operation wherever possible, optimal power allocations among amplifier blocks, and the sizing of devices to improve matching and reduce noise. We envision that the micropower amplifier can be used as part of a wireless EKG monitoring system powered by rectified radio-frequency energy or other forms of energy harvesting like body vibration and body heat. PMID:23853270

  17. A vircator amplifier

    International Nuclear Information System (INIS)

    A cavity vircator has demonstrated that formation of a virtual cathode in a cavity can improve microwave production efficiency and narrow the radiation bandwidth. When the virtual cathode radiates the microwave fields grow from noise. For each cavity, there is only one or a limited number of allowable modes for a given frequency. In this paper, a novel device - a vircator amplifier is described. The device consists of a relativistic magnetron and a cavity vircator with both devices powered by a 1 MeV, 3 Ω, 65 ns FWHM pulser. The idea is to inject a signal from the magnetron before and during virtual cathode formation in a cavity. The injected signal should lock the frequency and enhance electron bunching and therefore improve efficiency further. Experiments underway to evaluate the amplifier operating characteristics are discussed. The applicability of vircator amplifiers to the next generation of high-power microwave devices are addressed

  18. STABILIZED TRANSISTOR AMPLIFIER

    Science.gov (United States)

    Noe, J.B.

    1963-05-01

    A temperature stabilized transistor amplifier having a pair of transistors coupled in cascade relation that are capable of providing amplification through a temperature range of - 100 un. Concent 85% F to 400 un. Concent 85% F described. The stabilization of the amplifier is attained by coupling a feedback signal taken from the emitter of second transistor at a junction between two serially arranged biasing resistances in the circuit of the emitter of the second transistor to the base of the first transistor. Thus, a change in the emitter current of the second transistor is automatically corrected by the feedback adjustment of the base-emitter potential of the first transistor and by a corresponding change in the base-emitter potential of the second transistor. (AEC)

  19. Principal modes in fiber amplifiers

    CERN Document Server

    Fridman, Moti; Dubinskii, Mark; Friesem, Asher A; Davidson, Nir

    2010-01-01

    The dynamics of the state of polarization in single mode and multimode fiber amplifiers are presented. The experimental results reveal that although the state of polarizations at the output can vary over a large range when changing the temperatures of the fiber amplifiers, the variations are significantly reduced when resorting to the principal states of polarization in single mode fiber amplifiers and principal modes in multimode fiber amplifiers.

  20. Helical Fiber Amplifier

    Science.gov (United States)

    Koplow, Jeffrey P.; Kliner, Dahy; Goldberg, Lew

    2002-12-17

    A multi-mode gain fiber is provided which affords substantial improvements in the maximum pulse energy, peak power handling capabilities, average output power, and/or pumping efficiency of fiber amplifier and laser sources while maintaining good beam quality (comparable to that of a conventional single-mode fiber source). These benefits are realized by coiling the multimode gain fiber to induce significant bend loss for all but the lowest-order mode(s).

  1. Radio Frequency Solid State Amplifiers

    CERN Document Server

    Jacob, J

    2015-01-01

    Solid state amplifiers are being increasingly used instead of electronic vacuum tubes to feed accelerating cavities with radio frequency power in the 100 kW range. Power is obtained from the combination of hundreds of transistor amplifier modules. This paper summarizes a one hour lecture on solid state amplifiers for accelerator applications.

  2. Electronic amplifiers for automatic compensators

    CERN Document Server

    Polonnikov, D Ye

    1965-01-01

    Electronic Amplifiers for Automatic Compensators presents the design and operation of electronic amplifiers for use in automatic control and measuring systems. This book is composed of eight chapters that consider the problems of constructing input and output circuits of amplifiers, suppression of interference and ensuring high sensitivity.This work begins with a survey of the operating principles of electronic amplifiers in automatic compensator systems. The succeeding chapters deal with circuit selection and the calculation and determination of the principal characteristics of amplifiers, as

  3. Simplified design of IC amplifiers

    CERN Document Server

    Lenk, John

    1996-01-01

    Simplified Design of IC Amplifiers has something for everyone involved in electronics. No matter what skill level, this book shows how to design and experiment with IC amplifiers. For experimenters, students, and serious hobbyists, this book provides sufficient information to design and build IC amplifier circuits from 'scratch'. For working engineers who design amplifier circuits or select IC amplifiers, the book provides a variety of circuit configurations to make designing easier.Provides basics for all phases of practical design.Covers the most popular forms for amplif

  4. Building valve amplifiers

    CERN Document Server

    Jones, Morgan

    2013-01-01

    Building Valve Amplifiers is a unique hands-on guide for anyone working with tube audio equipment--as an electronics hobbyist, audiophile or audio engineer. This 2nd Edition builds on the success of the first with technology and technique revisions throughout and, significantly, a major new self-build project, worked through step-by-step, which puts into practice the principles and techniques introduced throughout the book. Particular attention has been paid to answering questions commonly asked by newcomers to the world of the valve, whether audio enthusiasts tackling their first build or

  5. Wideband amplifier design

    CERN Document Server

    Hollister, Allen L

    2007-01-01

    In this book, the theory needed to understand wideband amplifier design using the simplest models possible will be developed. This theory will be used to develop algebraic equations that describe particular circuits used in high frequency design so that the reader develops a ""gut level"" understanding of the process and circuit. SPICE and Genesys simulations will be performed to show the accuracy of the algebraic models. By looking at differences between the algebraic equations and the simulations, new algebraic models will be developed that include parameters originally left out of the model

  6. REGENERATIVE TRANSISTOR AMPLIFIER

    Science.gov (United States)

    Kabell, L.J.

    1958-11-25

    Electrical circults for use in computers and the like are described. particularly a regenerative bistable transistor amplifler which is iurned on by a clock signal when an information signal permits and is turned off by the clock signal. The amplifier porforms the above function with reduced power requirements for the clock signal and circuit operation. The power requirements are reduced in one way by employing transformer coupling which increases the collector circuit efficiency by eliminating the loss of power in the collector load resistor.

  7. Quantum entanglement degrees amplifier

    CERN Document Server

    Wu, Xiang-Yao; Liu, Xiao-Jing; Liang, Yu; Meng, Xiang-Dong; Li, Hong; Zhang, Si-Qi

    2015-01-01

    The quantum entangled degrees of entangled states become smaller with the transmission distance increasing, how to keep the purity of quantum entangled states is the puzzle in quantum communication. In the paper, we have designed a new type entanglement degrees amplifier by one-dimensional photonic crystal, which is similar as the relay station of classical electromagnetic communication. We find when the entangled states of two-photon and three-photon pass through photonic crystal, their entanglement degrees can be magnified, which make the entanglement states can be long range propagation and the quantum communication can be really realized.

  8. DIAMOND AMPLIFIED PHOTOCATHODES.

    Energy Technology Data Exchange (ETDEWEB)

    SMEDLEY,J.; BEN-ZVI, I.; BOHON, J.; CHANG, X.; GROVER, R.; ISAKOVIC, A.; RAO, T.; WU, Q.

    2007-11-26

    High-average-current linear electron accelerators require photoinjectors capable of delivering tens to hundreds of mA average current, with peak currents of hundreds of amps. Standard photocathodes face significant challenges in meeting these requirements, and often have short operational lifetimes in an accelerator environment. We report on recent progress toward development of secondary emission amplifiers for photocathodes, which are intended to increase the achievable average current while protecting the cathode from the accelerator. The amplifier is a thin diamond wafer which converts energetic (few keV) primary electrons into hundreds of electron-hole pairs via secondary electron emission. The electrons drift through the diamond under an external bias and are emitted into vacuum via a hydrogen-terminated surface with negative electron affinity (NEA). Secondary emission gain of over 200 has been achieved. Two methods of patterning diamond, laser ablation and reactive-ion etching (RIE), are being developed to produce the required geometry. A variety of diagnostic techniques, including FTIR, SEM and AFM, have been used to characterize the diamonds.

  9. Universal Signal Conditioning Amplifier

    Science.gov (United States)

    Kinney, Frank

    1997-01-01

    The Technological Research and Development Authority (TRDA) and NASA-KSC entered into a cooperative agreement in March of 1994 to achieve the utilization and commercialization of a technology development for benefiting both the Space Program and U.S. industry on a "dual-use basis". The technology involved in this transfer is a new, unique Universal Conditioning Amplifier (USCA) used in connection with various types of transducers. The project was initiated in partnership with I-Net Corporation, Lockheed Martin Telemetry & Instrumentation (formerly Loral Test and Information Systems) and Brevard Community College. The project consists of designing, miniaturizing, manufacturing, and testing an existing prototype of USCA that was developed for NASA-KSC by the I-Net Corporation. The USCA is a rugged and field-installable self (or remotely)- programmable amplifier that works in combination with a tag random access memory (RAM) attached to various types of transducers. This summary report comprises performance evaluations, TRDA partnership tasks, a project summary, project milestones and results.

  10. Characterisation Of Low Noise Amplifier

    OpenAIRE

    MAULIK B.PATEL; ABHISEK CHOBEY; SUNIL B.PATEL

    2012-01-01

    Amplification is one of the most basic and prevalent microwave circuit functions inmodern RF and microwave systems. Early microwave amplifiers relied on tubes, such asklystrons and traveling-wave tubes, or solid-state reflection amplifiers based on thenegative resistance characteristics of tunnel or varactor diodes. But due to the dramaticimprovements and innovations in solid-state technology that have occurred since the1970s, most RF and microwave amplifiers today use transistor devices such...

  11. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther;

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  12. Amplified leak detection

    Energy Technology Data Exchange (ETDEWEB)

    Mahony, James

    2011-12-15

    Leaks are one of the major concerns for oil and gas producers. But recently, a Calgary-based company developed a tool that can find natural gas leaks in wellbores. This has relieved the oil and gas producers because the optics of finding downhole leaks just got a little brighter. Since then, there have been continuous efforts to broaden and refine fiber optics based methods. This paper presents amplified leak detection using fiber optics to identify even the smallest liquid leaks downhole. At high volumes, detection of downhole leaks in liquids is not a problem but at lower flow rates, the leaks become harder to detect, and at very low flow rates, they might not be detected at all. Hifi Engineering Inc. has developed the LeakSonar fiber optic acoustic sensor array that is specifically designed to detect and locate fluid migration in wellbores, even through multiple strings of casing.

  13. Metatronic transistor amplifier

    Science.gov (United States)

    Chettiar, Uday K.; Engheta, Nader

    2015-10-01

    Utilizing the notion of metamaterials, in recent years the concept of a circuit and lumped circuit elements have been extended to the optical domains, providing the paradigm of optical metatronics, i.e., metamaterial-inspired optical nanocircuitry, as a powerful tool for design and study of more complex systems at the nanoscale. In this paper we present a design for a new metatronic element, namely, a metatronic transistor that functions as an amplifier. As shown by our analytical and numerical paper here, this metatronic transistor provides gain as well as isolation between the input and output ports of such two-port device. The cascadability and fan-out aspects of this element are also explored.

  14. Semiconductor DC amplifier AEP 1487

    International Nuclear Information System (INIS)

    A semiconductor dc amplifier has been designed with the object of achieving low drift without component selection or special temperature-balancing adjustments. Modulator and ac-amplifier techniques have been adopted in order to avoid the drifts that occur when transistors are directly coupled. The diode-ring modulator described in CREL-902 has been used as the input chopper. (author)

  15. Small signal microwave amplifier design

    CERN Document Server

    Grosch, Theodore

    2000-01-01

    This book explains techniques and examples for designing stable amplifiers for high-frequency applications in which the signal is small and the amplifier circuit is linear. An in-depth discussion of linear network theory provides the foundation needed to develop actual designs. Examples throughout the book will show you how to apply the knowledge gained in each chapter leading to the complex design of low noise amplifiers. Many exercises at the end of each chapter will help students to practice their skills. The solutions to these design problems are available in an accompanying solutions book

  16. International Standardization Activities for Optical Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Haruo Okamura

    2003-01-01

    International standardization activities for Optical Amplifiers at IECTC86 and ITU-T SG15 are reviewed. Current discussions include Optical Amplifier safety guideline, Reliability standard, Rest methods of Noise and PMD, Definitions of Raman amplifier parameters and OA classification.

  17. A Transformer Class E Amplifier

    Directory of Open Access Journals (Sweden)

    Mikolajewski Miroslaw

    2014-12-01

    Full Text Available In a high-efficiency Class E ZVS resonant amplifier a matching and isolation transformer can replace some or even all inductive components of the amplifier thus simplifying the circuit and reducing its cost. In the paper a theoretical analysis, a design example and its experimental verification for a transformer Class E amplifier are presented. In the experimental amplifier with a transformer as the only inductive component in the circuit high efficiency ηMAX = 0.95 was achieved for supply voltage VI = 36 V, maximum output power POMAX = 100 W and the switching frequency f = 300 kHz. Measured parameters and waveforms showed a good agreement with theoretical predictions. Moreover, the relative bandwidth of the switching frequency was only 19% to obtain output power control from 4.8 W to POMAX with efficiency not less than 0.9 in the regulation range.

  18. TARC: Carlo Rubbia's Energy Amplifier

    CERN Multimedia

    Laurent Guiraud

    1997-01-01

    Transmutation by Adiabatic Resonance Crossing (TARC) is Carlo Rubbia's energy amplifier. This CERN experiment demonstrated that long-lived fission fragments, such as 99-TC, can be efficiently destroyed.

  19. New Packaging for Amplifier Slabs

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thorsness, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suratwala, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rogowski, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-18

    The following memo provides a discussion and detailed procedure for a new finished amplifier slab shipping and storage container. The new package is designed to maintain an environment of <5% RH to minimize weathering.

  20. Transistor oscillator and amplifier grids

    OpenAIRE

    Weikle, Robert M., II; Kim, Moonil; Hacker, Jonathan B.; De Lisio, Michael P.; Popvić, Zoya B.; Rutledge, David B.

    1992-01-01

    Although quasi-optical techniques are applicable to a large variety of solid-state devices, special attention is given to transistors, which are attractive because they can be used as either amplifiers or oscillators. Experimental results for MESFET bar-grid and planar grid oscillators are presented. A MESFET grid amplifier that receives only vertically polarized waves at the input and radiates horizontally polarized waves at the output is discussed. These planar grids can be scaled for opera...

  1. A KIND OF NEW AMPLIFIER

    Institute of Scientific and Technical Information of China (English)

    YIN XUN-HE; FENG RU-PENG; REN YONG

    2000-01-01

    Chaotic characteristics in the iteration of logistic map (one-dimensional discrete dynamic system) are simulatedand analyzed. The circuit implementation of a kind of chaotic amplifier model is based on the chaotic characteristicsthat chaos is sensitively dependent on its initial conditions, and the circuit simulation result is given using simulationprogram with integrated circuit emphasis for personal computer (PSPICE), and is compared with linear amplifier.Advantages and disadvantages of such a model are indicated.

  2. Casimir force on amplifying bodies

    OpenAIRE

    Sambale, Agnes; Welsch, Dirk-Gunnar; Buhmann, Stefan Yoshi; Dung, Ho Trung

    2009-01-01

    Based on a unified approach to macroscopic QED that allows for the inclusion of amplification in a limited space and frequency range, we study the Casimir force as a Lorentz force on an arbitrary partially amplifying system of linearly locally responding (isotropic) magnetoelectric bodies. We demonstrate that the force on a weakly polarisable/magnetisable amplifying object in the presence of a purely absorbing environment can be expressed as a sum over the Casimir--Polder forces on the excite...

  3. Low-Noise Band-Pass Amplifier

    Science.gov (United States)

    Kleinberg, L.

    1982-01-01

    Circuit uses standard components to overcome common limitation of JFET amplifiers. Low-noise band-pass amplifier employs JFET and operational amplifier. High gain and band-pass characteristics are achieved with suitable choice of resistances and capacitances. Circuit should find use as low-noise amplifier, for example as first stage instrumentation systems.

  4. EMI-resilient amplifier circuits

    CERN Document Server

    van der Horst, Marcel J; Linnenbank, André C

    2014-01-01

    This book enables circuit designers to reduce the errors introduced by the fundamental limitations and electromagnetic interference (EMI) in negative-feedback amplifiers.  The authors describe a systematic design approach for application specific negative-feedback amplifiers, with specified signal-to-error ratio (SER).  This approach enables designers to calculate noise, bandwidth, EMI, and the required bias parameters of the transistors used in  application specific amplifiers in order to meet the SER requirements.   ·         Describes design methods that incorporate electromagnetic interference (EMI) in the design of application specific negative-feedback amplifiers; ·         Provides designers with a structured methodology to avoid the use of trial and error in meeting signal-to-error ratio (SER) requirements; ·         Equips designers to increase EMI immunity of the amplifier itself, thus avoiding filtering at the input, reducing the number of components and avoiding detr...

  5. Spectroscopic amplifier for pin diode

    International Nuclear Information System (INIS)

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  6. Gaussian amplifier for nuclear spectrometry

    International Nuclear Information System (INIS)

    One of the major goals of nuclear spectrometry is the determination of the energy spectrum of a radioactive source. To measure this spectrum with electronic instrumentation one need to use a nuclear spectrometry chain of which the amplifier is part of, and whose filter shaping considerably influences the final energy resolution achieved. The amplifier released accomplishes a 7th order Gaussian filter shape with Taylor series approximation synthesized by the Shifted Companion Form and mounted using only electronic components availablein Brazil. The final version has been tested and the results showed a very good performance and the energy resolution achieved was equivalent to the imported models. (Author)

  7. A wideband dc-coupled amplifier

    International Nuclear Information System (INIS)

    A method is described whereby an ac-coupled high-frequency amplifier and a dc-coupled low-frequency amplifier are connected in parallel in order to obtain a dc-coupled wideband amplifier. By using an operational amplifier which compares the output voltage with the input voltage, the low-frequency amplifier contributes to the overall gain only when the gain of the ac-coupled amplifier droops at low frequencies. Thus, no frequency splitting networks are necessary and the excellent low-frequency features of an operational amplifier are added to those of the ac-coupled wideband amplifier. As an example, a low noise amplifier is described which exhibits a hundredfold gain, a bandwidth from dc to 550 MHz, an input bias current of less than 1 nA, and an output voltage range of ±1 V

  8. Characterisation Of Low Noise Amplifier

    Directory of Open Access Journals (Sweden)

    MAULIK B.PATEL

    2012-08-01

    Full Text Available Amplification is one of the most basic and prevalent microwave circuit functions inmodern RF and microwave systems. Early microwave amplifiers relied on tubes, such asklystrons and traveling-wave tubes, or solid-state reflection amplifiers based on thenegative resistance characteristics of tunnel or varactor diodes. But due to the dramaticimprovements and innovations in solid-state technology that have occurred since the1970s, most RF and microwave amplifiers today use transistor devices such as Si or SiGeBJTs, GaAs HBTs, GaAs or InP FETs, or GaAs HEMTs. Microwave transistor amplifiersare rugged, low-cost, reliable, and can be easily integrated in both hybrid andmonolithic integrated circuitry. Transistor amplifiers can be used at frequencies inexcess of 100 GHz in a wide range of applications requiring small size, low-noise figure,broad bandwidth, and low to medium power capacity. Although microwave tubes are stillrequired for very high power and/or very high frequency applications, continuingimprovement in the performance of microwave transistors is steadily reducing the needfor microwave tubes

  9. Dielectric waveguide amplifiers and lasers

    NARCIS (Netherlands)

    Pollnau, M.

    2014-01-01

    The performance of semiconductor amplifiers and lasers has made them the preferred choice for optical gain on a micro-chip. In the past few years, we have demonstrated that also rare-earth-ion-doped dielectric waveguides show remarkable performance, ranging from a small-signal gain per unit length o

  10. Low Cost RF Amplifier for Community TV

    Science.gov (United States)

    Ch, Syafaruddin; Sasongko, Sudi Mariyanto Al; Made Budi Suksmadana, I.; Mustiko Okta Muvianto, Cahyo; Ariessaputra, Suthami

    2016-01-01

    he capability of television to deliver audio video makes this media become the most effective method to spread information. This paper presents an experiment of RF amplifier design having low-cost design and providing sufficient RF power particularly for community television. The RF amplifier consists of two stages of amplifier. The first stage amplifier was used to leverage output of TV modulator from 11dBm to enable to drive next stage amplifier. CAD simulation and fabrication were run to reach optimum RF amplifier design circuit. The associated circuit was made by determining stability circle, stability gain, and matching impedance. Hence, the average power of first stage RF amplifier was 24.68dBm achieved. The second stage used RF modules which was ready match to 50 ohm for both input and output port. The experiment results show that the RF amplifier may operate at frequency ranging from 174 to 230MHz. The average output power of the 2nd stage amplifier was 33.38 Watt with the overall gain of 20.54dB. The proposed RF amplifier is a cheap way to have a stable RF amplifier for community TV. The total budget for the designed RF amplifier is only a 1/5 compared to local design of final TV amplifier.

  11. Amplifying the evanescent field of free electrons

    OpenAIRE

    So, J.-K.; Ou, J.-Y.; Adamo, G.; García de Abajo, F. J.; MacDonald, K. F.; Zheludev, N.I.

    2013-01-01

    We provide the first experimental demonstration that the evanescent field of free electrons can be amplified by a plasmonic nanolayer in much that same way as optical evanescent fields are amplified in the ‘poor-man’s superlens’.

  12. Amplifying free-electron evanescent fields

    OpenAIRE

    So, J.-K.; Ou, J.-Y.; Adamo, G.; García de Abajo, F. J.; MacDonald, K. F.; Zheludev, N.I.

    2013-01-01

    We show experimentally for the first time that free-electron evanescent fields can be amplified by a plasmonic nanolayer in a manner analogous to the way in which optical fields are amplified in the poor-man's superlens.

  13. Analog circuit design designing high performance amplifiers

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The third volume Designing High Performance Amplifiers applies the concepts from the first two volumes. It is an advanced treatment of amplifier design/analysis emphasizing both wideband and precision amplification.

  14. Compact dual channel spectroscopy amplifier cum discriminator

    International Nuclear Information System (INIS)

    A single width NIM module having two channels of spectroscopy amplifier cum discriminator has been developed for Nuclear Physics experiments at IUAC. Each channel contains a shaping amplifier along with logic circuits to generate the energy and timing information respectively

  15. Single conversion stage amplifier - SICAM

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2005-12-15

    This Ph.D. thesis presents a thorough analysis of the so called SICAM - SIngle Converter stage AMplifier approach to building direct energy conversion audio power amplifiers. The mainstream approach for building isolated audio power amplifiers today consists of isolated DC power supply and Class D amplifier, which essentially represents a two stage solution, where each of the components can be viewed as separate and independent part. The proposed SICAM solution strives for direct energy conversion from the mains to the audio output, by dedicating the operation of the components one to another and integrating their functions, so that the final audio power amplifier represents a single-stage topology with higher efficiency, lower volume, less board space, lower component count and subsequently lower cost. The SICAM approach is both applicable to non-isolated and isolated audio power amplifiers, but the problems encountered in these two cases are different. Non-isolated SICAM solutions are intended for both AC mains-connected and battery-powered devices. In non-isolated mains-connected SICAMs the main idea is to simplify the power supply or even provide integrated power factor correction (PFC) functions, while still maintaining low component stress and good audio performance by generally decreasing the input voltage level to the Class D audio power amplifier. On the other hand, non-isolated battery-powered SICAMs have to cope with the ever changing battery voltage and provide output voltage levels which are both lower and higher than the battery voltage, while still being simple and single-stage energy conversion solutions. In isolated SICAMs the isolation transformer adjusts the voltage level on the secondary side to the desired level, so the main challenges here are decreasing the size of the magnetic core and reducing the number and size of bulky reactive components as much as possible. The main focus of this thesis is directed towards the isolated SICAMs and

  16. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.; Di Carlo, A.; Dispenza, M.; Dolfi, D.; Durand, A.; Fiorello, A.; Gohier, A.; Guiset, P.; Korantia, M.; Krozer, V.; Legagneux, P.; Marchesin, R.; Megtert, S.; Bouamrane, F.; Mineo, M.; Paoloni, C.; Pham, K.; Schnell, J.P.; Secchi, A.; Tamburri, E.; Terranova, M.L.; Ulisse, G.; Zhurbenko, Vitaliy

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...... European research, academy and industry in vacuum electronics. This paper describes the status of the project and progress towards the THz amplifier realization....

  17. Improved charge amplifier using hybrid hysteresis compensation

    Science.gov (United States)

    Amin-Shahidi, Darya; Trumper, David L.

    2013-08-01

    We present a novel charge amplifier, with a robust feedback circuit and a method for compensating piezoelectric actuator's hysteresis at low frequencies. The amplifier uses a modified feedback circuit which improves robustness to the addition of series load impedance such as in cabling. We also describe a hybrid hysteresis compensation method for enabling the charge amplifier to reduce hysteresis at low frequencies. Experimental results demonstrate the utility of the new amplifier design.

  18. Quantum Theory of Laser Amplifiers.

    Science.gov (United States)

    Mander, Gillian Linda

    Available from UMI in association with The British Library. Requires signed TDF. We calculate the input-output characteristics of a below threshold laser amplifier. Expressions are derived for the output second- and fourth-order spectral and temporal correlation functions in terms of the corresponding input quantities, and for the photocount first and second factorial moments for both homodyne and direct detection. The general results are applied to several cases of practical interest, including specific non-classical input states. We show that a maximum of twofold amplification is permitted if squeezing in the input is to survive at the output. Similarly, for preservation of photon antibunching in amplification we show that only very small gains are allowed. The model treated here provides a detailed example of the amplifier noise limitations imposed by quantum mechanics. In particular, we show that minimum noise occurs in a cavity that is asymmetric with respect to the mirror reflectivities. The latter part of this work treats the above threshold laser amplifier. The laser output is back-scattered from a moving target to provide a weak Doppler-shifted signal which re-enters the laser cavity and is amplified. We show that the three-level atomic lasing medium is equivalent to a two-level medium pumped by an inverted bath. We use the methods of quantum statistical analysis to obtain time -evolution equations for the c-number amplitudes of the laser and signal fields. We show that the results may be applied to the below threshold regime for appropriate values of the pump parameter. By considering the amplitude differential gain we show explicitly that the behaviour of the laser around threshold is characteristic of a second -order phase transition. We calculate the output intensity gain appropriate to a heterodyne detection process, and find good agreement between the predicted gain profiles and measured data for both carbon dioxide and argon-ion lasers.

  19. Compact, harmonic multiplying gyrotron amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Guo, H.Z.; Granatstein, V.L.; Antonsen, T.M. Jr.; Levush, B.; Tate, J.; Chen, S.H. [Univ. of Maryland, College Park, MD (United States). Inst. for Plasma Research

    1995-12-31

    A compact, harmonic multiplying gyrotron traveling wave amplifier is being developed. The device is a three-stage tube with the output section running as a fourth harmonic gyro-TWT, the input section running as a fundamental gyro-TWT, and the middle operating at the second harmonic of the cyclotron frequency. Radiation is suppressed by servers between the sections. The operating beam of the tube is produced by a magnetron injection gun (MIG). A TE{sub 0n} mode selective interaction circuit consisting of mode converters and a filter waveguide is employed for both input and output sections to solve the mode competition problem, which is pervasive in gyro-TWT operation. The input section has an input coupler designed as a TE{sub 0n} mode launcher. It excites a signal at the fundamental cyclotron frequency (17.5 GHz), which is amplified in the first TWT interaction region. So far the device is similar to a two-stage harmonic gyro-TWT. The distinction is that in the three-stage device the second section will be optimized not for output power but for fourth harmonic bunching of the beam. A gyroklystron amplifier has also been designed. The configuration is similar to the gyro-TWT but with the traveling wave interaction structures replaced by mode selective special complex cavities. Cold test results of the wideband input coupler and the TE{sub 0n} mode selective interaction circuit have been obtained.

  20. SPS RF System Amplifier plant

    CERN Multimedia

    1977-01-01

    The picture shows a 2 MW, 200 MHz amplifier plant with feeder lines. The main RF-system of the SPS comprises four cavities: two of 20 m length and two of 16.5 m length. They are all installed in one long straight section (LSS 3). These cavities are of the travelling-wave type operating at a centre frequency of 200.2 MHz. They are wideband, filling time about 700 ns and untuned. The power amplifiers, using tetrodes are installed in a surface building 200 m from the cavities. Initially only two cavities were installed, a third cavity was installed in 1978 and a forth one in 1979. The number of power amplifiers was also increased: to the first 2 MW plant a second 2 MW plant was added and by end 1979 there were 8 500 kW units combined in pairs to feed each of the 4 cavities with up to about 1 MW RF power, resulting in a total accelerating voltage of about 8 MV. See also 7412016X, 7412017X, 7411048X.

  1. European Research on THz Vacuum Amplifiers

    DEFF Research Database (Denmark)

    Brunetti, F.; Cojocarua, C.-S.; de Rossi, A.;

    2010-01-01

    The OPTHER (OPtically Driven TeraHertz AmplifiERs) project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within this project is a consolidation of efforts at the international level from the main players of the Eu...

  2. NASA developments in solid state power amplifiers

    Science.gov (United States)

    Leonard, Regis F.

    1990-01-01

    Over the last ten years, NASA has undertaken an extensive program aimed at development of solid state power amplifiers for space applications. Historically, the program may be divided into three phases. The first efforts were carried out in support of the advanced communications technology satellite (ACTS) program, which is developing an experimental version of a Ka-band commercial communications system. These first amplifiers attempted to use hybrid technology. The second phase was still targeted at ACTS frequencies, but concentrated on monolithic implementations, while the current, third phase, is a monolithic effort that focusses on frequencies appropriate for other NASA programs and stresses amplifier efficiency. The topics covered include: (1) 20 GHz hybrid amplifiers; (2) 20 GHz monolithic MESFET power amplifiers; (3) Texas Instruments' (TI) 20 GHz variable power amplifier; (4) TI 20 GHz high power amplifier; (5) high efficiency monolithic power amplifiers; (6) GHz high efficiency variable power amplifier; (7) TI 32 GHz monolithic power amplifier performance; (8) design goals for Hughes' 32 GHz variable power amplifier; and (9) performance goals for Hughes' pseudomorphic 60 GHz power amplifier.

  3. Solid state, S-band, power amplifier

    Science.gov (United States)

    Digrindakis, M.

    1973-01-01

    The final design and specifications for a solid state, S-band, power amplifier is reported. Modifications from a previously proposed design were incorporated to improve efficiency and meet input overdrive and noise floor requirements. Reports on the system design, driver amplifier, power amplifier, and voltage and current limiter are included along with a discussion of the testing program.

  4. Solid state ku-band power amplifier

    Science.gov (United States)

    Bowers, H. C.; Lockyear, W. H.

    1972-01-01

    The design, fabrication, and testing of two types of IMPATT diode reflection amplifiers and a transmission amplifier are given. The Ku-band IMPATT diode development is discussed. Circuitry and electrical performance of the final version of the Ku-band amplifier is described. Construction details and an outline and mounting drawing are presented.

  5. low pump power photonic crystal fibre amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.; Broeng, Jes; Bjarklev, Anders Overgaard

    2003-01-01

    Designs of low pump power optical amplifiers, based on photonic crystal fibres are presented. The potential of these fibre amplifiers is investigated, and it is demonstrated that such amplifiers may deliver gains of more than 15 dB at 1550 nm with less than 1 mW of optical pump power....

  6. NIF/LMJ prototype amplifier mechanical design

    International Nuclear Information System (INIS)

    Amplifier prototypes for the National Ignition Facility and the Laser Megajoule will be tested at Lawrence Livermore National Laboratory. The prototype amplifier, which is an ensemble of modules from LLNL and Centre d'Etudes de Limeil-Valenton, is cassette-based with bottom access for maintenance. A sealed maintenance transfer vehicle which moves optical cassettes between the amplifier and the assembly cleanroom, and a vacuum gripper which holds laser slabs during cassette assembly will also be tested. The prototype amplifier will be used to verify amplifier optical performance, thermal recovery time, and cleanliness of mechanical operations

  7. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. The amplifier is constructed in a fully differential topology to maximize noise rejection. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved....... A continuous-time current-steering offset-compensation technique is utilized in order to minimize the noise contribution and to minimize dynamic impact on the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard...

  8. HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

    International Nuclear Information System (INIS)

    Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

  9. High temperature charge amplifier for geothermal applications

    Science.gov (United States)

    Lindblom, Scott C.; Maldonado, Frank J.; Henfling, Joseph A.

    2015-12-08

    An amplifier circuit in a multi-chip module includes a charge to voltage converter circuit, a voltage amplifier a low pass filter and a voltage to current converter. The charge to voltage converter receives a signal representing an electrical charge and generates a voltage signal proportional to the input signal. The voltage amplifier receives the voltage signal from the charge to voltage converter, then amplifies the voltage signal by the gain factor to output an amplified voltage signal. The lowpass filter passes low frequency components of the amplified voltage signal and attenuates frequency components greater than a cutoff frequency. The voltage to current converter receives the output signal of the lowpass filter and converts the output signal to a current output signal; wherein an amplifier circuit output is selectable between the output signal of the lowpass filter and the current output signal.

  10. Audio power amplifier design handbook

    CERN Document Server

    Self, Douglas

    2013-01-01

    This book is essential for audio power amplifier designers and engineers for one simple reason...it enables you as a professional to develop reliable, high-performance circuits. The Author Douglas Self covers the major issues of distortion and linearity, power supplies, overload, DC-protection and reactive loading. He also tackles unusual forms of compensation and distortion produced by capacitors and fuses. This completely updated fifth edition includes four NEW chapters including one on The XD Principle, invented by the author, and used by Cambridge Audio. Cro

  11. Cathode-follower power amplifier

    International Nuclear Information System (INIS)

    In circular accelerators and particularly in storage rings it is essential that the total impedance, as seen by the beam, be kept below some critical value. A model of the accelerating system was built using a single-ended cathode-follower amplifier driving a ferrite-loaded cavity. The system operated at 234.5 kHz with a peak output voltage of +-10 kV on the gap. The dynamic output impedance, as measured on the gap, was < 15 ohms

  12. High power RF solid state power amplifier system

    Science.gov (United States)

    Sims, III, William Herbert (Inventor); Chavers, Donald Gregory (Inventor); Richeson, James J. (Inventor)

    2011-01-01

    A high power, high frequency, solid state power amplifier system includes a plurality of input multiple port splitters for receiving a high-frequency input and for dividing the input into a plurality of outputs and a plurality of solid state amplifier units. Each amplifier unit includes a plurality of amplifiers, and each amplifier is individually connected to one of the outputs of multiport splitters and produces a corresponding amplified output. A plurality of multiport combiners combine the amplified outputs of the amplifiers of each of the amplifier units to a combined output. Automatic level control protection circuitry protects the amplifiers and maintains a substantial constant amplifier power output.

  13. High-efficiency solid state power amplifier

    Science.gov (United States)

    Wallis, Robert E. (Inventor); Cheng, Sheng (Inventor)

    2005-01-01

    A high-efficiency solid state power amplifier (SSPA) for specific use in a spacecraft is provided. The SSPA has a mass of less than 850 g and includes two different X-band power amplifier sections, i.e., a lumped power amplifier with a single 11-W output and a distributed power amplifier with eight 2.75-W outputs. These two amplifier sections provide output power that is scalable from 11 to 15 watts without major design changes. Five different hybrid microcircuits, including high-efficiency Heterostructure Field Effect Transistor (HFET) amplifiers and Monolithic Microwave Integrated Circuit (MMIC) phase shifters have been developed for use within the SSPA. A highly efficient packaging approach enables the integration of a large number of hybrid circuits into the SSPA.

  14. YANG-MILLS FIELD AMPLIFIER

    Directory of Open Access Journals (Sweden)

    Trunev A. P.

    2015-09-01

    Full Text Available The article presents a project of the Yang-Mills amplifier. Amplifier model is a multilayer spherical shell with increasing density towards the center. In the center of the amplifier is the core of high-density material. It is shown that in such a system, the amplitude of the Yang-Mills waves rises from the periphery to the center of several orders of magnitude. The role of the Yang-Mills field in the processes occurring in the nuclei of galaxies, stars and planets is discussed. The data modeling to strengthen the Yang-Mills field in the bowels of the planet, with an atomic explosion, and in some special devices such as the voltaic pile. To describe the mechanism of amplification chromodynamics field used as accurate results in Yang-Mills theory and numerical models developed based on an average and the exact equations as well. Among the exact solutions of the special role played by the centralsymmetric metric describing the contribution of the Yang-Mills field in the speed of recession of galaxies. Among the approximate numerical models can be noted the eight-scalar model we have developed for the simulation of non-linear color oscillations and chaos in the Yang-Mills theory. Earlier models were investigated spatio-temporal oscillations of the YangMills theory in the case of three and eight colors. The results of numerical simulation show that the nonlinear interaction does not lead to a spatial mixing of colors as it might be in the case of turbulent diffusion. Depending on the system parameters there is a suppression of the amplitude of the oscillations the first three by five colors or vice versa. The kinetic energy fluctuations or shared equally between the color components, or dominated by the kinetic energy of repressed groups of colors. In the present study, we found that amplification chromodynamic field leads to a sharp increase in the amplitude of the suppressed color, which can lead to an increase in entropy, excitation of nuclear

  15. Enhanced Gain in Photonic Crystal Amplifiers

    DEFF Research Database (Denmark)

    Ek, Sara; Semenova, Elizaveta; Hansen, Per Lunnemann;

    2012-01-01

    study of a 1 QW photonic crystal amplifier. Net gain is achieved which enables laser oscillation in photonic crystal micro cavities. The ability to freely tailor the dispersion in a semiconductor optical amplifier makes it possible to raise the optical gain considerably over a certain bandwidth. These...... results are promising for short and efficient semiconductor optical amplifiers. This effect will also benefit other devices, such as mode locked lasers....

  16. Reflection amplifiers in self-regulated learning

    OpenAIRE

    Verpoorten, Dominique

    2012-01-01

    Verpoorten, D. (2012). Reflection amplifiers in self-regulated learning. Doctoral thesis. November, 9, 2012, Heerlen, The Netherlands: Open Universiteit (CELSTEC). Datawyse / Universitaire Pers Maastricht.

  17. Dynamics of Soliton Cascades in Fiber Amplifiers

    CERN Document Server

    Arteaga-Sierra, F R; Agrawal, Govind P

    2016-01-01

    We study numerically the formation of cascading solitons when femtosecond optical pulses are launched into a fiber amplifier with less energy than required to form a soliton of equal duration. As the pulse is amplified, cascaded fundamental solitons are created at different distances, without soliton fission, as each fundamental soliton moves outside the gain bandwidth through the Raman-induced spectral shifts. As a result, each input pulse creates multiple, temporally separated, ultrashort pulses of different wavelengths at the amplifier output. The number of pulses depends not only on the total gain of the amplifier but also on the width of input pulses.

  18. Ping-pong auto-zero amplifier with glitch reduction

    Science.gov (United States)

    Larson, Mark R.

    2008-01-22

    A ping-pong amplifier with reduced glitching is described. The ping-pong amplifier includes a nulling amplifier coupled to a switching network. The switching network is used to auto-zero a ping amplifier within a ping-pong amplifier. The nulling amplifier drives the output of a ping amplifier to a proper output voltage level during auto-zeroing of the ping amplifier. By being at a proper output voltage level, glitches associated with transitioning between a ping amplifier and a pong amplifier are reduced or eliminated.

  19. Linearisation of RF Power Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck

    2001-01-01

    linearisation systems with focus on polar modulation feedback, and a chip oriented part focusing on integrating of separate building blocks of the system on a chip. The system oriented part of this thesis deals with analog feedback linearisation systems. The Polar modulation feedback system is compared with the...... more traditional Cartesian modulation feedback system in terms of loop settlement and dependencies between the feedback signals. A method to calculate the distortion functions of the linearisation system (AM/AM and AM/PM)based on the distortion functions of the power amplifier is presented. Also the...... polar loop architecture and it’s suitability to modern digital transmitters is discussed. A proposal of an architecture that is suitable for digital transmitters, which means that it has an interface to the digital back-end, defined by low-pass signals in polar form, is presented. Simulation guidelines...

  20. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  1. Amplified spontaneous emission and its restraint in a terawatt Ti:sapphire amplifier

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Amplified spontaneous emission (ASE) and its restraint in a femtosecond Ti: sapphire chirped_pulse amplifier were investigated. The noises arising from ASE were effectively filtered out in the spatial, temporal and spectral domain. Pulses as short as 38 fs were amplified to peak power of 1.4 TW. The power ratio between the amplified femtosecond pulse and the ASE was higher than 106:1.

  2. Distributed feedback laser amplifiers combining the functions of amplifiers and channel filters

    DEFF Research Database (Denmark)

    Wang, Z.; Durhuus, T.; Mikkelsen, Benny;

    1994-01-01

    A dynamic model for distributed feedback amplifiers, including the mode coupled equations and the carrier rate equation, is established. The presented mode coupled equations have taken into account the interaction between fast changing optical signal and the waveguide with corrugations. By showin...... the possibility of amplifying 100 ps pulses without pulse broadening, we anticipate that a distributed feedback amplifier can be used as a combined amplifier and channel filter in high bit rate transmission systems....

  3. A general-purpose pulse amplifier

    International Nuclear Information System (INIS)

    In the paper proposals are made for using the technique, known from analogue computation, for transforming nuclear pulses to the shape and size desired by the means of ''operational amplifiers''. By using this technique it is possible, by means of one fundamental amplifier but with different feedback networks, to have pre-amplifiers and head-amplifiers with different pulse-handling performances and optimized with respect to the parameter of greatest interest, such as linearity, stability or overloading characteristics. As this technique involves the use of parallel-feedback it is specially suited for pre-amplifiers since most detectors are current-generators. An amplifier fulfilling the requirements necessary for use as an operational amplifier is described. The most important specifications are: 90 db gain from DC-10 kHz, then falling approximately 20 db/decade until 15 MHz (30 db gain). Four tubes are used in the amplifier. For most pulse-handling applications a stabilized power-supply is unnecessary and the stability will depend solely on the stability of the feedback network used. (author)

  4. Self-pulsation in Raman fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, Martin Erland Vestergaard; Ott, Johan Raunkjær; Rottwitt, Karsten

    2009-01-01

    Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.......Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated....

  5. High efficiency, low magnetic field gyroklystron amplifiers

    International Nuclear Information System (INIS)

    The possibility of operating a gyroklystron amplifier at high efficiency and low magnetic field is considered. Two devices are discussed: A two cavity second harmonic TE02 gyroklystron amplifier operating at 19.7 GHz with subharmonic bunching, and a fundamental mode TE01 gyrotwistron at 16 GHz. The nonlinear efficiency is given for both devices

  6. BROADBAND TRAVELLING WAVE SEMICONDUCTOR OPTICAL AMPLIFIER

    DEFF Research Database (Denmark)

    2010-01-01

    Broadband travelling wave semiconductor optical amplifier (100, 200, 300, 400, 800) for amplification of light, wherein the amplifier (100, 200, 300, 400, 800) comprises a waveguide region (101, 201, 301, 401, 801) for providing confinement of the light in transverse directions and adapted for...

  7. Waveguide optical amplifier for telecom applications

    OpenAIRE

    Taccheo, Stefano; Zannin, Marcelo; Ennser, Karin; Careglio, Davide; Solé Pareta, Josep; Aracil Rico, Javier

    2009-01-01

    In this paper we review progress in optical gain clamped waveguide amplifiers for applications to optical communications. We demonstrate that compact waveguide devices may offer advantages compared to standard fiber amplifiers. In particular we focus on the application of gain clamping and optical burst switching networks where physical impairments may occur due to variation of the input power. Peer Reviewed

  8. mm-wave solid state amplifiers

    Science.gov (United States)

    Wolfert, P. H.; Crowley, J. D.; Fank, F. B.

    The development of mm-wave amplifiers using InP Gunn diodes is reviewed including a low-noise eight-stage amplifier for replacement of a Ka-band TWTA and a three-stage amplifier for the 42.5 to 44.5 range with an output power of 100 mW and 20 dB associated gain. A detailed description of a three-stage amplifier for the 54 to 58 GHz range is given with 100 mW output power and 15 dB associated gain, a small signal gain of 30 dB and an N.F. of 15.5 to 16.5 dB. The design of a broad band, low-loss V-band circulator, which was used in the amplifier, is described.

  9. Detection of Non-Amplified Genomic DNA

    CERN Document Server

    Corradini, Roberto

    2012-01-01

    This book offers a state-of-the-art overview on non amplified DNA detection methods and provides chemists, biochemists, biotechnologists and material scientists with an introduction to these methods. In fact all these fields have dedicated resources to the problem of nucleic acid detection, each contributing with their own specific methods and concepts. This book will explain the basic principles of the different non amplified DNA detection methods available, highlighting their respective advantages and limitations. The importance of non-amplified DNA sequencing technologies will be also discussed. Non-amplified DNA detection can be achieved by adopting different techniques. Such techniques have allowed the commercialization of innovative platforms for DNA detection that are expected to break into the DNA diagnostics market. The enhanced sensitivity required for the detection of non amplified genomic DNA has prompted new strategies that can achieve ultrasensitivity by combining specific materials with specifi...

  10. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.;

    2002-01-01

    We have produced GaAs-based quantum-dot edge-emitting lasers operating at 1.16 mu m with record-low transparency current, high output power, and high internal quantum efficiencies. We have also realized GaAs-based quantum-dot lasers emitting at 1.3 mu m, both high-power edge emitters and low-power...... biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...... surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier is...

  11. Radiation tolerant isolation amplifiers for temperature measurement

    International Nuclear Information System (INIS)

    This paper concentrates on the selection of radiation tolerant isolation amplifiers, which are suitable for the signal conditioners for cryogenic system in the Large Hadron Collider (LHC). The evolution and the results of different commercial isolation amplifiers' parameters under neutron and gamma radiation are presented. In most cases, the tested isolation amplifiers' input offset voltage, bias currents and output offset voltage hardly changed during the radiation. The DC gain in input stage was only affected for some isolation amplifiers with a small open loop gain. Transmission coefficient showed decrease for all the tested isolation amplifiers. Also, the DC output voltage increased and the ripple voltage decreased for all the build-in isolated regulators. In addition, results on 1B41 signal conditioner showed that it was tolerant to 7-8x1012 n/cm2, which was 50% higher than the expected dose in the LHC

  12. An Implantable CMOS Amplifier for Nerve Signals

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Lehmann, Torsten

    2001-01-01

    In this paper, a low noise high gain CMOS amplifier for minute nerve signals is presented. By using a mixture of weak- and strong inversion transistors, optimal noise suppression in the amplifier is achieved. A continuous-time offset-compensation technique is utilized in order to minimize impact on...... the amplifier input nodes. The method for signal recovery from noisy nerve signals is presented. A prototype amplifier is realized in a standard digital 0.5 μm CMOS single poly, n-well process. The prototype amplifier features a gain of 80 dB over a 3.6 kHz bandwidth, a CMRR of more than 87 dB and a...

  13. Design and performance of the beamlet amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Erlandson, A.C.; Rotter, M.D.; Frank, M.D.; McCracken, R.W.

    1996-06-01

    In future laser systems, such as the National Ignition Facility (NIF), multi-segment amplifiers (MSAs) will be used to amplify the laser beam to the required levels. As a prototype of such a laser architecture, the authors have designed, built, and tested flash-lamp-pumped, Nd:Glass, Brewster-angle slab MSAs for the Beamlet project. In this article, they review the fundamentals of Nd:Glass amplifiers, describe the MSA geometry, discuss parameters that are important in amplifier design, and present our results on the characterization of the Beamlet MSAs. In particular, gain and beam steering measurements show that the Beamlet amplifiers meet all optical performance specifications and perform close to model predictions.

  14. Qubit readout with a directional parametric amplifier

    Science.gov (United States)

    Sliwa, K. M.; Abdo, B.; Narla, A.; Shankar, S.; Hatridge, M.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2014-03-01

    Josephson junction based quantum limited parametric amplifiers play an essential role in superconducting qubit measurements. These measurements necessitate circulators and isolators between the amplifier and qubit to add directionality and/or isolation. Unfortunately, this extra hardware limits both quantum measurement efficiency and experimental scalability. Here we present a quantum-limited Josephson-junction-based directional amplifier (JDA) based on a novel coupling between two nominally identical Josephson parametric converters (JPCs). The device achieves a forward gain of 11 dB with a 15 MHz dynamical bandwidth, but higher gains are possible at the expense of bandwidth. We also present measurements of a transmon qubit made with the JDA, and show minimal measurement back-action despite the absence of any isolator or circulator before the amplifier. These results provide a first step toward realizing on-chip integration of qubits and parametric amplifiers. Work supported by: IARPA, ARO, and NSF.

  15. Design of an 1800nm Raman amplifier

    DEFF Research Database (Denmark)

    Svane, Ask Sebastian; Rottwitt, Karsten

    2013-01-01

    We present the experimental results for a Raman amplifier that operates at 1810 nm and is pumped by a Raman fiber laser at 1680 nm. Both the pump laser and the Raman amplifier is polarization maintaining. A challenge when scaling Raman amplifiers to longer wavelengths is the increase in...... transmission loss, but also the reduction in the Raman gain coefficient as the amplifier wavelength is increased. Both polarization components of the Raman gain is characterized, initially for linearly co-polarized signal and pump, subsequently linearly polarized orthogonal signal and pump. The noise...... performance of the amplifier is also investigated for both configurations. Our results show an on/off gain exceeding 20 dB at 1810 nm for which the obtained effective noise figure is below 3 dB....

  16. The 60 GHz solid state power amplifier

    Science.gov (United States)

    Mcclymonds, J.

    1991-01-01

    A new amplifier architecture was developed during this contract that is superior to any other solid state approach. The amplifier produced 6 watts with 4 percent efficiency over a 2 GHz band at 61.5 GHz. The unit was 7 x 9 x 3 inches in size, 5.5 pounds in weight, and the conduction cooling through the baseplate is suitable for use in space. The amplifier used high efficiency GaAs IMPATT diodes which were mounted in 1-diode circuits, called modules. Eighteen modules were used in the design, and power combining was accomplished with a proprietary passive component called a combiner plate.

  17. Laser Cooled High-Power Fiber Amplifier

    OpenAIRE

    Nemova, Galina

    2009-01-01

    A theoretical model for laser cooled continuous-wave fiber amplifier is presented. The amplification process takes place in the Tm3+-doped core of the fluoride ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) glass fiber. The cooling process takes place in the Yb3+:ZBLAN fiber cladding. It is shown that for each value of the pump power and the amplified signal there is a distribution of the concentration of the Tm3+ along the length of the fiber amplifier, which provides its athermal operation. The influence ...

  18. Effect of Soliton Propagation in Fiber Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The propagation of optical solitons in fiber amplifiers is discussed by considering a model that includes linear high order dispersion, two-photon absorption, nonlinear high-order dispersion, self-induced Ramam and five-order nonlinear effects. Based on travelling wave method, the solutions of the nonlinear Schrdinger equations, and the influence on soliton propagation as well as high-order effect in the fiber amplifier are discussed in detail. It is found that because of existing five-order nonlinear effect, the solution is not of secant hyperbola type, but shows high gain state of the fiber amplifier which is very favourable to the propagation of solitons.

  19. Noise reduction in AC-coupled amplifiers

    OpenAIRE

    Serrano Finetti, Roberto Ernesto; Pallàs Areny, Ramon

    2014-01-01

    AC-coupled amplifiers are noisier than dc-coupled amplifiers because of the thermal noise of the resistor(s) in the ac-coupling network and the increased contribution of the amplifier input noise current i(n). Both contributions, however, diminish if the corner frequency f(c) of the high-pass filter observed by the signal is lowered, the cost being a longer transient response. At the same time, the presence of large resistors in the ac-coupling network suggests that the use of FET-input ampli...

  20. Fundamentals of RF and microwave transistor amplifiers

    CERN Document Server

    Bahl, Inder J

    2009-01-01

    A Comprehensive and Up-to-Date Treatment of RF and Microwave Transistor Amplifiers This book provides state-of-the-art coverage of RF and microwave transistor amplifiers, including low-noise, narrowband, broadband, linear, high-power, high-efficiency, and high-voltage. Topics covered include modeling, analysis, design, packaging, and thermal and fabrication considerations. Through a unique integration of theory and practice, readers will learn to solve amplifier-related design problems ranging from matching networks to biasing and stability. More than 240 problems are included to help read

  1. High Energy Single Frequency Resonant Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...

  2. Noise in phase-preserving linear amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Pandey, Shashank; Jiang, Zhang; Combes, Joshua [Center for Quantum Information and Control, University of New Mexico, Albuquerque, NM 87131-0001 (United States); Caves, Carlton M. [Center for Quantum Information and Control, University of New Mexico, Albuquerque, NM 87131-0001, USA and Centre for Engineered Quantum Systems, School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072 (Australia)

    2014-12-04

    The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state σ for the ancillary mode; σ determines the properties of the added noise.

  3. Noise in phase-preserving linear amplifiers

    Science.gov (United States)

    Pandey, Shashank; Jiang, Zhang; Combes, Joshua; Caves, Carlton M.

    2014-12-01

    The purpose of a phase-preserving linear amplifier is to make a small signal larger, so that it can be perceived by instruments incapable of resolving the original signal, while sacrificing as little as possible in signal-to-noise. Quantum mechanics limits how well this can be done: the noise added by the amplifier, referred to the input, must be at least half a quantum at the operating frequency. This well-known quantum limit only constrains the second moments of the added noise. Here we provide the quantum constraints on the entire distribution of added noise: any phasepreserving linear amplifier is equivalent to a parametric amplifier with a physical state σ for the ancillary mode; σ determines the properties of the added noise.

  4. Cryogenic Amplifier Based Receivers at Submillimeter Wavelengths

    Science.gov (United States)

    Chattopadhyay, Goutam; Reck, Theodore and; Schlecht, Erich; Lin, Robert; Deal, William

    2012-01-01

    The operating frequency of InP high electron mobility transistor (HEMT) based amplifiers has moved well in the submillimeter-wave frequencies over the last couple of years. Working amplifiers with usable gain in waveguide packages has been reported beyond 700 GHz. When cooled cryogenically, they have shown substantial improvement in their noise temperature. This has opened up the real possibility of cryogenic amplifier based heterodyne receivers at submillimeter wavelengths for ground-based, air-borne, and space-based instruments for astrophysics, planetary, and Earth science applications. This paper provides an overview of the science applications at submillimeter wavelengths that will benefit from this technology. It also describes the current state of the InP HEMT based cryogenic amplifier receivers at submillimeter wavelengths.

  5. Quantum cloning with an optical fiber amplifier

    OpenAIRE

    Fasel, Sylvain; Gisin, Nicolas; Ribordy, Grégoire; Scarani, Valerio; Zbinden, Hugo

    2002-01-01

    It has been shown theoretically that a light amplifier working on the physical principle of stimulated emission should achieve optimal quantum cloning of the polarization state of light. We demonstrate close-to-optimal universal quantum cloning of polarization in a standard fiber amplifier for telecom wavelengths. For cloning 1 --> 2 we find a fidelity of 0.82, the optimal value being 5/6 = 0.83.

  6. V-band IMPATT power amplifier

    Science.gov (United States)

    Schell, S. W.

    1985-09-01

    This program is the result of the continuing demand and future requirement for a high data rate 60-GHz communications link. A reliable solid-state transmitter which delivers the necessary power over a wide bandwidth using the present IMPATT diode technology required the development of combining techniques. The development of a 60-GHz IMPATT power combiner amplifier is detailed. The results form a basis from which future wideband, high-power IMPATT amplifiers may be developed. As a result, several state-of-the-art advancements in millimeter-wave components technology were achieved. Specific achievements for the amplifier integration were: development of a nonresonant divider/combiner circuit; reproducible multiple junction circulator assemblies; and reliable high power 60-GHz IMPATT diodes. The various design approaches and tradeoffs which lead to the final amplifier configuration are discussed. A detailed circuit design is presented for the various amplifier components, and the conical line combiner, radial line combiner, and circulator development are discussed. The performance of the amplifier, the overall achievement of the program, the implications of the results, and an assessment of future development needs and recommendations are examined.

  7. Multiple excitation regenerative amplifier inertial confinement system

    International Nuclear Information System (INIS)

    The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation

  8. An improved AC-amplifier for electrophysiology

    Directory of Open Access Journals (Sweden)

    Jorgovanović Nikola

    2009-01-01

    Full Text Available We present the design, simulation and test results of a new AC amplifier for electrophysiological measurements based on a three op-amp instrumentation amplifier (IA. The design target was to increase the common mode rejection ratio (CMRR, thereby improving the quality of the recorded physiological signals in a noisy environment. The new amplifier actively suppresses the DC component of the differential signal and actively reduces the common mode signal in the first stage of the IA. These functions increase the dynamic range of the amplifier's first stage of the differential signal. The next step was the realization of the amplifier in a single chip technology. The design and tests of the new AC amplifier with a differential gain of 79.2 dB, a CMRR of 130 dB at 50 Hz, a high-pass cutoff frequency at 0.01 Hz and common mode reduction in the first stage of the 49.8 dB are presented in this paper.

  9. The OPTHER Project: Progress toward the THz Amplifier

    DEFF Research Database (Denmark)

    Paoloni, C; Brunetti, F; Di Carlo, A;

    2011-01-01

    This paper describes the status of the OPTHER (OPtically driven TeraHertz AmplifiERs) project and progress toward the THz amplifier realization. This project represents a considerable advancement in the field of high frequency amplification. The design and realization of a THz amplifier within th...

  10. Pulsed ti: sapphire laser power amplifier

    International Nuclear Information System (INIS)

    We have demonstrated an all solid state Ti:Sapphire laser system consisting of a power oscillator and single pass amplifier. The electrical-to-optical efficiency far exceeds that of the current CW systems. The pump lasers have lower capital and operating costs than the Argon-ion laser. In the future, we plan to scale the output power to higher levels by adding a fourth pump laser and improving the output power of the current pump lasers. Modeling results suggest that a large increase in efficiency can be realized by improving the beam quality of the pump lasers, even at the cost of reduced output power. We will explore this option by adding apertures to the cavity and/or reducing the rod diameter along with optimizing the resonator design. Other improvements in efficiency which will be investigated include double passing the amplifier for better extraction. To complete this work, the laser system will be converted into a two-stage amplifier. A narrow band, lower power oscillator currently under development will be injected in to the amplifier to study the extraction and efficiency characteristics of the amplifier throughout the tuning range of Ti:Sapphire. Detailed beam quality measurements will also be made. Other work will include doubling the narrow band output for materials processing applications

  11. Single mode terahertz quantum cascade amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Y., E-mail: yr235@cam.ac.uk; Wallis, R.; Shah, Y. D.; Jessop, D. S.; Degl' Innocenti, R.; Klimont, A.; Kamboj, V.; Beere, H. E.; Ritchie, D. A. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, CB3 0HE Cambridge (United Kingdom)

    2014-10-06

    A terahertz (THz) optical amplifier based on a 2.9 THz quantum cascade laser (QCL) structure has been demonstrated. By depositing an antireflective coating on the QCL facet, the laser mirror losses are enhanced to fully suppress the lasing action, creating a THz quantum cascade (QC) amplifier. Terahertz radiation amplification has been obtained, by coupling a separate multi-mode THz QCL of the same active region design to the QC amplifier. A bare cavity gain is achieved and shows excellent agreement with the lasing spectrum from the original QCL without the antireflective coating. Furthermore, a maximum optical gain of ∼30 dB with single-mode radiation output is demonstrated.

  12. Ultrashort pulse amplification in cryogenically cooled amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Backus, Sterling J.; Kapteyn, Henry C.; Murnane, Margaret Mary

    2004-10-12

    A laser amplifier system amplifies pulses in a single "stage" from .about.10.sup.-9 joules to more than 10.sup.-3 joules, with average power of 1-10 watts, and beam quality M.sup.2 <2. The laser medium is cooled substantially below room temperature, as a means to improve the optical and thermal characteristics of the medium. This is done with the medium inside a sealed, evacuated or purged cell to avoid moisture or other materials condensing on the surface. A "seed" pulse from a separate laser is passed through the laser medium, one or more times, in any of a variety of configurations including single-pass, multiple-pass, and regenerative amplifier configurations.

  13. Transistorized pulse amplifiers (A.I.T.)

    International Nuclear Information System (INIS)

    The two amplifiers whose design and operation are described in this report have been studied for neutron detection units used in piles. They are designed to allow an important reduction of the volume and of the weight of the detector and its amplifier, and to simplify the operation of the detection assembly. To these characteristics can be added the mechanical and electrical robustness and the very reduced micro-phony. The first transistorized amplifier (AIT.1) is simple, very robust, and can be used for radioprotection installations. The second (AIT.4) has a better performance and makes it possible to replace the APT.2 in most of its applications (it has even been used satisfactorily in an apparatus where the micro-phony and the sensitivity to interference of the APT.2 made this latter unusable). (author)

  14. An automated test facility for neutronic amplifiers

    International Nuclear Information System (INIS)

    Neutronic amplifiers are used at the Chalk River Laboratory in applications such as neutron flux monitoring and reactor control systems. Routine preventive maintenance of control and safety systems included annual calibration and characterization of the neutronic amplifiers. An investigation into the traditional methods of annual routine maintenance of amplifiers concluded that frequency and phase response measurements in particular were labour intensive and subject to non-repeatable errors. A decision was made to upgrade testing methods and facilities by using programmable test equipment under the control of a computer. In order to verify the results of the routine measurements, expressions for the transfer functions were derived from the circuit diagrams. Frequency and phase responses were then calculated and plotted thus providing a bench-mark to which the test results can be compared. (author)

  15. Cryogenic cooling for high power laser amplifiers

    OpenAIRE

    Perin J.P.; Millet F.; Divoky M.; Rus B.

    2013-01-01

    Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz). The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 1...

  16. Transportable setup for amplifier phase fidelity measurements

    Science.gov (United States)

    Tröbs, M.; Bogan, C.; Barke, S.; Kühn, G.; Reiche, J.; Heinzel, G.; Danzmann, K.

    2015-05-01

    One possible laser source for the Laser Interferometer Space Antenna (LISA) consists of an Ytterbium-doped fiber amplifier originally developed for inter-satellite communication, seeded by the laser used for the technology demonstrator mission LISA Pathfinder. LISA needs to transmit clock information between its three spacecraft to correct for phase noise between the clocks on the individual spacecraft. For this purpose phase modulation sidebands at GHz frequencies will be imprinted on the laser beams between spacecraft. Differential phase noise between the carrier and a sideband introduced within the optical chain must be very low. We report on a transportable setup to measure the phase fidelity of optical amplifiers.

  17. Optimization of Pr3+:ZBLAN fiber amplifiers

    DEFF Research Database (Denmark)

    Pedersen, B.; Miniscalco, J. W.; Quimby, R. S.

    1992-01-01

    Experimental parameters have been measured and used in a quantitative model of Pr3+-doped fluorozirconate fiber amplifiers. The optimum cutoff wavelength was determined to be 800 nm and the gain for 400 mW of pump was found to increase from 12 to 34 dB if the NA was increased from 0.15 to 0.......25. Lengthening the metastable state lifetime from 110 to 300 μs would significantly improve amplifier performance while concentration quenching can appreciably degrade it...

  18. Beyond nonlinear saturation of backward Raman amplifiers

    Science.gov (United States)

    Barth, Ido; Toroker, Zeev; Balakin, Alexey A.; Fisch, Nathaniel J.

    2016-06-01

    Backward Raman amplification is limited by relativistic nonlinear dephasing resulting in saturation of the leading spike of the amplified pulse. Pump detuning is employed to mitigate the relativistic phase mismatch and to overcome the associated saturation. The amplified pulse can then be reshaped into a monospike pulse with little precursory power ahead of it, with the maximum intensity increasing by a factor of two. This detuning can be employed advantageously both in regimes where the group velocity dispersion is unimportant and where the dispersion is important but small.

  19. Operational amplifier circuits analysis and design

    CERN Document Server

    Nelson, J C C

    1995-01-01

    This book, a revised and updated version of the author's Basic Operational Amplifiers (Butterworths 1986), enables the non-specialist to make effective use of readily available integrated circuit operational amplifiers for a range of applications, including instrumentation, signal generation and processing.It is assumed the reader has a background in the basic techniques of circuit analysis, particularly the use of j notation for reactive circuits, with a corresponding level of mathematical ability. The underlying theory is explained with sufficient but not excessive, detail. A range of compu

  20. Ultra-low Voltage CMOS Cascode Amplifier

    DEFF Research Database (Denmark)

    Lehmann, Torsten; Cassia, Marco

    In this paper, we design a folded cascode operational transconductance amplifier in a standard CMOS process, which has a measured 69 dB DC gain, a 2 MHz bandwidth and compatible input- and output voltage levels at a 1 V power supply. This is done by a novel Current Driven Bulk (CDB) technique...

  1. Compensation techniques for operational amplifier bias current

    International Nuclear Information System (INIS)

    Two techniques are proposed for the compensation of the input current on operational amplifiers that can be used on inverting and non-inverting configurations. A qualitative analysis of temperature drift problems is made, and as a practical application, the construction of a voltage follower for high impedance measurements is presented. (Author)

  2. Stereoscopy Amplifies Emotions Elicited by Facial Expressions.

    Science.gov (United States)

    Hakala, Jussi; Kätsyri, Jari; Häkkinen, Jukka

    2015-12-01

    Mediated facial expressions do not elicit emotions as strongly as real-life facial expressions, possibly due to the low fidelity of pictorial presentations in typical mediation technologies. In the present study, we investigated the extent to which stereoscopy amplifies emotions elicited by images of neutral, angry, and happy facial expressions. The emotional self-reports of positive and negative valence (which were evaluated separately) and arousal of 40 participants were recorded. The magnitude of perceived depth in the stereoscopic images was manipulated by varying the camera base at 15, 40, 65, 90, and 115 mm. The analyses controlled for participants' gender, gender match, emotional empathy, and trait alexithymia. The results indicated that stereoscopy significantly amplified the negative valence and arousal elicited by angry expressions at the most natural (65 mm) camera base, whereas stereoscopy amplified the positive valence elicited by happy expressions in both the narrowed and most natural (15-65 mm) base conditions. Overall, the results indicate that stereoscopy amplifies the emotions elicited by mediated emotional facial expressions when the depth geometry is close to natural. The findings highlight the sensitivity of the visual system to depth and its effect on emotions. PMID:27551358

  3. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Hagen; Nielsen, Dennis; Knott, Arnold;

    2014-01-01

    using predistortion. This paper suggests linearizing a nonlinear bidirectional Cuk audio amplifier using an analog predistortion approach. A prototype power stage was built and results show that a voltage gain of up to 9 dB and reduction in THD from 6% down to 3% was obtainable using this approach....

  4. Investigation of the amplified spontaneous emission in Nd: glass disk laser amplifier

    International Nuclear Information System (INIS)

    A model program has been established to investigate the amplified spontaneous emission (ASE) in the Nd: glass disk amplifier with the Monte Carlo method and rays tracing. The distribution of ASE loading on the edge of a disk is firstly calculated. The effect of disk aspect radio on ASE gain reduction is also investigated. Allowance is made for the effect of different reflectivity under the condition of different incidence on two faces

  5. Plasmonic amplifier of the evanescent field of free electrons

    OpenAIRE

    So, J.-K.; Ou, J.Y.; Adamo, G.; García de Abajo, F. J.; MacDonald, K. F.; Zheludev, N.I.

    2013-01-01

    We show experimentally for the first time that free electron evanescent fields can be amplified by a plasmonic nanolayer in much that same way as optical evanescent fields are amplified in the poor-man's super-lens.

  6. Cryogenic cooling for high power laser amplifiers

    International Nuclear Information System (INIS)

    Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz). The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K-170 K with a heat flux of 1 MW*m-2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser. (authors)

  7. Cryogenic cooling for high power laser amplifiers

    Science.gov (United States)

    Perin, J. P.; Millet, F.; Divoky, M.; Rus, B.

    2013-11-01

    Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz). The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K-170 K with a heat flux of 1 MW*m-2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  8. Fundamentals of fiber lasers and fiber amplifiers

    CERN Document Server

    Ter-Mikirtychev, Valerii (Vartan)

    2014-01-01

    This book covers the fundamental aspects of fiber lasers and fiber amplifiers, and includes a wide range of material from laser physics fundamentals to state-of-the-art topics in this rapidly growing field of quantum electronics. Emphasis is placed on the nonlinear processes taking place in fiber lasers and amplifiers, their similarities, differences to, and their advantages over other solid-state lasers. The reader will learn basic principles of solid-state physics and optical spectroscopy of laser active centers in fibers, main operational laser regimes, and practical recommendations and suggestions on fiber laser research, laser applications, and laser product development. The book will be useful for students, researchers, and professionals who work with lasers, in the optical communications, chemical and biological industries, etc.

  9. Cryogenic cooling for high power laser amplifiers

    Directory of Open Access Journals (Sweden)

    Perin J.P.

    2013-11-01

    Full Text Available Using DPSSL (Diode Pumped Solid State Lasers as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YAG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz. The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K–170 K with a heat flux of 1 MW*m−2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser.

  10. High power single-frequency Innoslab amplifier.

    Science.gov (United States)

    Han, Ke-Zhen; Ning, Jian; Zhang, Bai-Tao; Wang, Yi-Ran; Zhang, Hai-Kun; Nie, Hong-Kun; Sun, Xiao-Li; He, Jing-Liang

    2016-07-10

    A laser diode array (LDA) end-pumped continuous-wave single-frequency Innoslab amplifier has been demonstrated. The Gaussian ray bundle method was used to model the light propagation in the Innoslab amplifier for the first time to the best of our knowledge. With discrete reflectors, the maximum output of 60 W with a linewidth of 44 MHz was achieved under the pump power of 245 W, corresponding to the optical-optical efficiency of 24.5%. The beam quality factor M2 at the output power of 51 W in the horizontal and vertical direction was measured to be 1.4 and 1.3, respectively. The long-term power instability in 2 h was less than 0.25%. PMID:27409308

  11. First lasing of the regenerative amplifier FEL

    International Nuclear Information System (INIS)

    The regenerative amplifier free-electron laser (RAFEL) is a high-gain RF-linac FEL capable of producing high optical power from a compact design. The combination of a high-gain and small optical feedback enables the FEL to reach saturation and produce a high optical power and high extraction efficiency without the risk of optical damage to the mirrors. This paper summarizes the first lasing of the regenerative amplifier FEL and describes recent experimental results. The highest optical energy achieved thus far at 16.3 μm is 1.7 J over a train of 900 micropulses. We infer pulse energy of 1.9 mJ in each 16 ps micropulse, corresponding to a peak power of 120 MW

  12. Noise Gain Features of Fiber Raman Amplifier

    Directory of Open Access Journals (Sweden)

    Georgii S. Felinskyi

    2016-01-01

    Full Text Available The formation dynamics of the optical noise in a silica single mode fiber (SMF as function of the pump power variation in the counter pumped fiber Raman amplifier (FRA is experimentally studied. The ratio between the power of amplified spontaneous emission and the power of incoherent optical noise is quantitatively determined by detailed analysis of experimental data in the pump powers range of 100–300 mW within the full band of Stokes frequencies, including FRA working wavelengths over the C + L transparency windows. It is found out the maximum of Raman gain coefficient for optical noise does not exceed ~60% of corresponding peak at the gain profile maximum of coherent signal. It is shown that the real FRA noise figure may be considerably less than 3 dB over a wide wavelength range (100 nm at a pump power of several hundreds of mW.

  13. SINGLE CONVERSION ISOLATED IMPEDANCE TRANSFORMATION AMPLIFIER

    DEFF Research Database (Denmark)

    2003-01-01

    The invention relates to a switch mode power amplifier. A first and a second change-over switch are inserted between a DC voltage supply and a primary side of an isolation transformer. Two secondary windings are connected to a power output terminal. A first and a second secondary side power switch...... are adapted to connect the two secondary windings to the power connector of the power output terminal. The pulse width modulation means is adapted to generate control signals for the driver means of the first and the second change-over switch so as to cause every second pulse to be inverted. The pulse...... width modulation means is also adapted to generate a third and a fourth control signal for said driver means of the power switches of said first and said second secondary. The invention also relates to a method of controlling a switch mode power amplifier...

  14. Application module of universal amplifier in education process

    OpenAIRE

    CHALOUPEK, Pavel

    2013-01-01

    This thesis deals with the teaching and implementation module for teaching in secondary schools and their role in education. Following the theory being discussed in relation to a valid educational program. Learning amplifier module implemented by the assignment to DPS. The activity of the amplifier module to simulate in Multisim simulation program. Next is made circuitry design in discrete amplifier module. There evaluated the feasibility and simulation of realizations amplifier module in sec...

  15. Noise and saturation properties of semiconductor quantum dot optical amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2002-01-01

    We present a detailed theoretical analysis of quantum dot optical amplifiers. Due to the presence of a reservoir of wetting layer states, the saturation and noise properties differ markedly from bulk or QW amplifiers and may be significantly improved.......We present a detailed theoretical analysis of quantum dot optical amplifiers. Due to the presence of a reservoir of wetting layer states, the saturation and noise properties differ markedly from bulk or QW amplifiers and may be significantly improved....

  16. Pump to signal noise transfer in parametric fiber amplifiers

    DEFF Research Database (Denmark)

    Lund-Hansen, Toke; Rottwitt, Karsten; Peucheret, Christophe; Lali-Dastjerdi, Zohreh; Rishøj, Lars Søgaard; Svane, Ask Sebastian; Andersen, Lasse Mejling; Cristofori, Valentina

    2010-01-01

    Fiber optic parametric amplifiers have been suggested due to their potential low spontaneous emission. However, by nature the parametric amplifier only work in a forward pumped configuration, which result in transfer of relative intensity noise in the pump to the signal.......Fiber optic parametric amplifiers have been suggested due to their potential low spontaneous emission. However, by nature the parametric amplifier only work in a forward pumped configuration, which result in transfer of relative intensity noise in the pump to the signal....

  17. Radiation and particle detector and amplifier

    Science.gov (United States)

    Schmidt, K. C. (Inventor)

    1973-01-01

    A radiation or charged particle detector is described which incorporates a channel multiplier structure to amplify the detected rays or particles. The channel multiplier structure has a support multiplying element with a longitudinal slot along one side. The element supports a pair of plates positioned contiguous with the slot. The plates funnel the particles or rays to be detected into the slotted aperture and the element, thus creating an effectively wide aperture detector of the windowless type.

  18. Amplifying the Hawking Signal in BECs

    Directory of Open Access Journals (Sweden)

    Roberto Balbinot

    2014-01-01

    Full Text Available We consider simple models of Bose-Einstein condensates to study analog pair-creation effects, namely, the Hawking effect from acoustic black holes and the dynamical Casimir effect in rapidly time-dependent backgrounds. We also focus on a proposal by Cornell to amplify the Hawking signal in density-density correlators by reducing the atoms’ interactions shortly before measurements are made.

  19. Design and simulation of a gyroklystron amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, M. S., E-mail: mschauhan.rs.ece@iitbhu.ac.in; Swati, M. V.; Jain, P. K. [Centre of Research in Microwave Tubes, Department of Electronics Engineering, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005 (India)

    2015-03-15

    In the present paper, a design methodology of the gyroklystron amplifier has been described and subsequently used for the design of a typically selected 200 kW, Ka-band, four-cavity gyroklystron amplifier. This conceptual device design has been validated through the 3D particle-in-cell (PIC) simulation and nonlinear analysis. Commercially available PIC simulation code “MAGIC” has been used for the electromagnetic study at the different location of the device RF interaction structure for the beam-absent case, i.e., eigenmode study as well as for the electron beam and RF wave interaction behaviour study in the beam present case of the gyroklystron. In addition, a practical problem of misalignment of the RF cavities with drift tubes within the tube has been also investigated and its effect on device performance studied. The analytical and simulation results confirmed the validity of the gyroklystron device design. The PIC simulation results of the present gyroklystron produced a stable RF output power of ∼218 kW for 0% velocity spread at 35 GHz, with ∼45 dB gain, 37% efficiency, and a bandwidth of 0.3% for a 70 kV, 8.2 A gyrating electron beam. The simulated values of RF output power have been found in agreement with the nonlinear analysis results within ∼5%. Further, the PIC simulation has been extended to study a practical problem of misalignment of the cavities axis and drift tube axis of the gyroklystron amplifier and found that the RF output power is more sensitive to misalignments in comparison to the device bandwidth. The present paper, gyroklystron device design, nonlinear analysis, and 3D PIC simulation using commercially available code had been systematically described would be of use to the high-power gyro-amplifier tube designers and research scientists.

  20. Design and simulation of a gyroklystron amplifier

    International Nuclear Information System (INIS)

    In the present paper, a design methodology of the gyroklystron amplifier has been described and subsequently used for the design of a typically selected 200 kW, Ka-band, four-cavity gyroklystron amplifier. This conceptual device design has been validated through the 3D particle-in-cell (PIC) simulation and nonlinear analysis. Commercially available PIC simulation code “MAGIC” has been used for the electromagnetic study at the different location of the device RF interaction structure for the beam-absent case, i.e., eigenmode study as well as for the electron beam and RF wave interaction behaviour study in the beam present case of the gyroklystron. In addition, a practical problem of misalignment of the RF cavities with drift tubes within the tube has been also investigated and its effect on device performance studied. The analytical and simulation results confirmed the validity of the gyroklystron device design. The PIC simulation results of the present gyroklystron produced a stable RF output power of ∼218 kW for 0% velocity spread at 35 GHz, with ∼45 dB gain, 37% efficiency, and a bandwidth of 0.3% for a 70 kV, 8.2 A gyrating electron beam. The simulated values of RF output power have been found in agreement with the nonlinear analysis results within ∼5%. Further, the PIC simulation has been extended to study a practical problem of misalignment of the cavities axis and drift tube axis of the gyroklystron amplifier and found that the RF output power is more sensitive to misalignments in comparison to the device bandwidth. The present paper, gyroklystron device design, nonlinear analysis, and 3D PIC simulation using commercially available code had been systematically described would be of use to the high-power gyro-amplifier tube designers and research scientists

  1. Design and simulation of a gyroklystron amplifier

    Science.gov (United States)

    Chauhan, M. S.; Swati, M. V.; Jain, P. K.

    2015-03-01

    In the present paper, a design methodology of the gyroklystron amplifier has been described and subsequently used for the design of a typically selected 200 kW, Ka-band, four-cavity gyroklystron amplifier. This conceptual device design has been validated through the 3D particle-in-cell (PIC) simulation and nonlinear analysis. Commercially available PIC simulation code "MAGIC" has been used for the electromagnetic study at the different location of the device RF interaction structure for the beam-absent case, i.e., eigenmode study as well as for the electron beam and RF wave interaction behaviour study in the beam present case of the gyroklystron. In addition, a practical problem of misalignment of the RF cavities with drift tubes within the tube has been also investigated and its effect on device performance studied. The analytical and simulation results confirmed the validity of the gyroklystron device design. The PIC simulation results of the present gyroklystron produced a stable RF output power of ˜218 kW for 0% velocity spread at 35 GHz, with ˜45 dB gain, 37% efficiency, and a bandwidth of 0.3% for a 70 kV, 8.2 A gyrating electron beam. The simulated values of RF output power have been found in agreement with the nonlinear analysis results within ˜5%. Further, the PIC simulation has been extended to study a practical problem of misalignment of the cavities axis and drift tube axis of the gyroklystron amplifier and found that the RF output power is more sensitive to misalignments in comparison to the device bandwidth. The present paper, gyroklystron device design, nonlinear analysis, and 3D PIC simulation using commercially available code had been systematically described would be of use to the high-power gyro-amplifier tube designers and research scientists.

  2. Electrically Pumped Vertical-Cavity Amplifiers

    DEFF Research Database (Denmark)

    Greibe, Tine

    2007-01-01

    In this work, the design of electrically pumped vertical cavity semiconductor optical amplifiers (eVCAs) for use in a mode-locked external-cavity laser has been developed, investigated and analysed. Four different eVCAs, one top-emitting and three bottom emitting structures, have been designed and...... discussed. The thesis concludes with recommendations for further work towards the realisation of compact electrically pumped mode-locked vertical externalcavity surface emitting lasers....

  3. CMOS RF Power Amplifiers for Wireless Communications

    OpenAIRE

    Fritzin, Jonas

    2011-01-01

    The wireless market has experienced a remarkable development and growth since the introduction of the first modern mobile phone systems, with a steady increase in the number of subscribers, new application areas, and higher data rates. As mobile phones and wireless connectivity have become consumer mass markets, the prime goal of the IC manufacturers is to provide low-cost solutions. The power amplifier (PA) is a key building block in all RF transmitters. To lower the costs and allow full int...

  4. Quantum noise in ideal operational amplifiers

    OpenAIRE

    Courty, Jean-Michel; Grassia, Francesca; Reynaud, Serge

    1998-01-01

    We consider a model of quantum measurement built on an ideal operational amplifier operating in the limit of infinite gain, infinite input impedance and null output impedance and with a feddback loop. We evaluate the intensity and voltage noises which have to be added to the classical amplification equations in order to fulfill the requirements of quantum mechanics. We give a description of this measurement device as a quantum network scattering quantum fluctuations from input to output ports.

  5. Amplifying youth voices in the developing world.

    Science.gov (United States)

    Fotenos, Saori; Rohatgi, Deepti

    2007-01-01

    Low-literacy youth in the slums of Brazil have been historically unequipped to share their ideas on how to improve their lives, because outside of the spoken word, it is difficult for them to express their thoughts persuasively. The Amplifying Voices afterschool video program piloted at Projeto Uerê in Rio de Janeiro shows that youth can leverage technological tools to voice their perspectives on social issues relevant to themselves and their communities. PMID:18271053

  6. X-band magnicon amplifier experiment

    International Nuclear Information System (INIS)

    The magnicon, a ''scanning beam'' microwave amplifier tube related to the gyrocon, is of interest as a possible replacement for klystron amplifiers in future linear accelerators. It consists of a multicavity deflection system, whose purpose is to spin up an electron beam to high transverse momentum (α ≡ υperpendicular / υz approx-gt 1), followed by an output cavity that employs a cyclotron resonant mechanism to extract principally the transverse beam momentum. The deflection cavities are designed to produce an electron beam whose entry point and guiding center rotate in space about the cavity axis at the drive frequency. The output cavity employs a synchronously rotating mode, making possible a highly efficient interaction. This paper presents an overview of magnicon theory and design considerations, and discusses the progress of an experimental program to develop a frequency-doubling magnicon amplifier at X-band. This magnicon will require a sequence of 3 or 4 deflection cavities, in order to generate the required transverse momentum, followed by an output cavity operating at twice the drive frequency. The initial experiment was designed to measure the gain between two such deflection cavities operating in the TM110 mode a 5.7 GHz. These cavities were powered by a 170A, 500 keV electron beam immersed in an 8.1 kG magnetic field. In low power amplifier experiments, a gain of ∼15 dB was observed in the preferred circular polarization, at a frequency shift of approximately -0.18%, and a gain of ∼3 dB in the opposite circular polarization, at a frequency shift of approximately +0.06%. These results are in good agreement with theory and numerical simulation. The complete magnicon experiment is presently under design, and will also be discussed

  7. Amplifier/compressor fiber Raman lasers.

    Science.gov (United States)

    Islam, M N; Mollenauer, L F; Stolen, R H; Simpson, J R; Shang, H T

    1987-10-01

    We show that the chirp from cross-phase modulation (XPM) dominates the operation of fiber Raman lasers (FRL's). Thus a FRL in the anomalous group-velocity regime is best described as a XPM-chirped Raman amplifier followed by a linear fiber compressor. While the output of such a laser is generally a narrow pulse with a broad pedestal, we show both experimentally and by computer simulation that negligible background is achievable. PMID:19741882

  8. Gyro-amplifiers modeling with MAGY

    Science.gov (United States)

    Levush, Baruch; Nguyen, Khanh; Botton, Moti; Vlasov Antonsen, Alexander, Jr.

    1999-11-01

    Recent modeling results of several experiments on gyroklystron amplifier at the Naval Research Laboratory are presented. Modeling was performed using the quasi three-dimensional, self-consistent code MAGY[1] . Amplifiers in both Ka- and W-bands have been studied [2,3]. Using known experimental input parameters, code-predicted salient amplifier performance characteristics, e.g. efficiency, bandwidth, drive curve, have been found to be in good agreement with experimental results. Self-consistent phenomena, such as effects of window reflections on bandwidth and higher-order-mode interaction in uptaper, will also be presented. MAGY has also been used to design gyro-TWTs. The code has been successfully benchmarked against linear theory. Issues such as absolute instability, backward-wave oscillations, and effect of reflection in gyro-TWTs have been investigated. Detailed results of design trade-off studies for a Ka-band gyro-TWT will also be presented and discussed. [1] M. Botton, et al.,IEEE Trans. Plasma Sci.,Vol.26(1998) [3] J.P. Calame, et al.,Phys. of Plasmas,Vol.6(1999) [4] M. Blank, et al.,Submitted to Phys. of Plasmas (1999)

  9. High Power 35GHz Gyroklystron Amplifiers

    Science.gov (United States)

    Choi, Jin; McCurdy, A.; Wood, F.; Kyser, R.; Danly, B.; Levush, B.; Parker, R.

    1997-05-01

    High power coherent radiation sources at 35GHz are attractive for next generation high gradient particle accelerators. A multi-cavity gyroklystron amplifier is considered a promising candidate for high power millimeter wave generation. Experiments on two-cavity and three cavity gyroklystron amplifiers are underway to demonstrate a 140kW, 35GHz coherent radiation amplification. Though this power is low compared with that needed for colliders, many of the issues associated with the bandwidth of such devices can be addressed in the present experiments. High bandwidth is important to permit the rapid phase shifts required for RF pulse compression schemes presently under investigation. Large signal calculations (P.E. Latham, W. Lawson, V. Irwin, IEEE Trans. Plasma Sci., Vol. 22, No. 5, pp. 804-817, 1994.) predict that the two-cavity gyroklystron produces a peak power of 140kW, corresponding to 33% efficiency. Calculations also show that a stagger tuned three cavity circuit increases a bandwidth to more than 0.7%. Experimental results of the amplifier will be presented and compared with the theory.

  10. The development of DUV chemically amplified resists

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, J.W.; Fedynyshyn, T.H.; Small, R.D. [Shipley Co. Inc., Marlboro, MA (United States)

    1993-12-31

    The development of deep ultraviolet (DUV) resists has necessitated the introduction of new concepts in resist materials and chemistry. Successful DUV resist systems now employ the concept of chemical amplification. This catalytic reaction leads to a substantial enhancement in the imaging dose. Another benefit of chemical amplified resists is that they allow the design of materials which can be transparent to DUV exposure wavelengths, yet they can still have high sensitivity. Commercial and prototype positive- and negative-tone resists are now readily available and these resists have been used in pilot production to make the most advanced integrated circuits with {le}0.35 {mu}m design rules. At Shipley, we have undertaken to develop both negative- and positive-tone chemically amplified resists for DUV lithography. These resists are capable of high resolution (0.3 {mu}m), fast photospeed ({le}30 mJ/sq. cm), and excellent etch resistance. This presentation will discuss the chemical and lithographic properties of the Shipley negative- and positive-tone DUV chemically amplified resists. General discussion of the importance of activation energy for the catalytic process, catalytic chain length, and environmental stability will be given.

  11. Charge sensitive amplifies. The state of arts

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kunishiro [Clear Pulse Co., Tokyo (Japan)

    1996-07-01

    In the radiation detectors, signals are essentially brought with charges produced by radiation, then it is naturally the best way to use a charge sensitive amplifier (CSA) system to extract those signals. The CSA is thought to be the best amplifier suitable to almost all the radiation detectors, if neglecting economical points of view. The CSA has been only applied to special fields like radiation detection because the concept of `charges` is not so universal against the concepts of `voltage` and `current`. The CSA, however, is low in noise and a high speed amplifier and may be applicable not only to radiation measurement but also piezoelectric devices and also bolometers. In this article, noise in the CSA, basic circuit on the CSA, concepts of `equivalent noise charge` (ENC), a method for the ENC, and importance of the `open-loop gain` in the CSA to achieve better performance of it and how to realize in a practical CSA were described. And, characteristics on a counting rate of the CSA, various circuit used in the CSA, and CSAs which are commercially available at present and special purpose CSAs were also introduced. (G.K.)

  12. Polarization of Tapered Semiconductor Travelling-Wave Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Huang Dexiu; Li Hong

    2001-01-01

    The polarization of a tapered semi-conductor travelling-wave amplifier has been investigated with the transfer matrix method based on convective equation. It is shown that the apparent polarization mode competition exists, and polarization-independent tapered semiconductor travellingwave amplifiers can be obtained through the optimization of amplifier parameters.

  13. Digital system provides superregulation of nanosecond amplifier-discriminator circuit

    Science.gov (United States)

    Forges, K. G.

    1966-01-01

    Feedback system employing a digital logic comparator to detect and correct amplifier drift provides stable gain characteristics for nanosecond amplifiers used in counting applications. Additional anticoincidence logic enables application of the regulation circuit to the amplifier and discriminator while they are mounted in an operable circuit.

  14. Analysis of multipass laser amplifier systems for storage laser media

    International Nuclear Information System (INIS)

    The performance characteristics of single pass and multipass storage laser amplifiers are presented and compared. The effects of the multipass amplifier parameters on the extraction characteristics are examined. For a wide range of conditions the multipass amplifier is found to provide high energy gain and high efficiency simultaneously. This is a significant advantage over the single pass laser amplifier. Finally, three specific storage laser amplifier systems, flashlamp pumped V:MgF2, XeF laser pumped Tm:Glass, and photolytically pumped Selenium, are examined. The performance characteristics for each of the three systems are calculated and compared

  15. Analysis of multipass laser amplifier systems for storage laser media

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, J.F.

    1980-03-25

    The performance characteristics of single pass and multipass storage laser amplifiers are presented and compared. The effects of the multipass amplifier parameters on the extraction characteristics are examined. For a wide range of conditions the multipass amplifier is found to provide high energy gain and high efficiency simultaneously. This is a significant advantage over the single pass laser amplifier. Finally, three specific storage laser amplifier systems, flashlamp pumped V:MgF/sub 2/, XeF laser pumped Tm:Glass, and photolytically pumped Selenium, are examined. The performance characteristics for each of the three systems are calculated and compared.

  16. Characterization of a Common-Gate Amplifier Using Ferroelectric Transistors

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; MacLeod, Todd C.; Ho, Fat D.

    2011-01-01

    In this paper, the empirical data collected through experiments performed using a FeFET in the common-gate amplifier circuit is presented. The FeFET common-gate amplifier was characterized by varying all parameters in the circuit, such as load resistance, biasing of the transistor, and input voltages. Due to the polarization of the ferroelectric layer, the particular behavior of the FeFET common-gate amplifier presents interesting results. Furthermore, the differences between a FeFET common-gate amplifier and a MOSFET common-gate amplifier are examined.

  17. Characterization of a Common-Source Amplifier Using Ferroelectric Transistors

    Science.gov (United States)

    Hunt, Mitchell; Sayyah, Rana; MacLeond, Todd C.; Ho, Pat D.

    2010-01-01

    This paper presents empirical data that was collected through experiments using a FeFET in the established common-source amplifier circuit. The unique behavior of the FeFET lends itself to interesting and useful operation in this widely used common-source amplifier. The paper examines the effect of using a ferroelectric transistor for the amplifier. It also examines the effects of varying load resistance, biasing, and input voltages on the output signal and gives several examples of the output of the amplifier for a given input. The difference between a commonsource amplifier using a ferroelectric transistor and that using a MOSFET is addressed.

  18. Low noise amplifier for ZnS(Ag) scintillation chamber

    International Nuclear Information System (INIS)

    A new pulse amplifier that can be used with standard photomultiplier tubes coupled with Zn(Ag) scintillation chamber is presented. The amplifier based on an IC operational amplifier LF 356N consists of a low-noise charge sensitive preamplifier and pulse shaping circuits for optimization of signal to noise ratio. Temperature instability is ≤ 0.05%/oC. Dynamic range for linear output signals is equal +7 V. The presented amplifier is used in a measuring head for 0.17 L Lucas chambers developed in Department of Nuclear Instruments and Methods of the INCT in laboratory investigations aimed to develop methods and instruments for measurement of radon concentration in the air. The amplifier can also be employed for measurement of ionizing radiation by means of other scintillators coupled to PM tube. The amplifier is followed by a pulse discriminator with adjustable discrimination level. The amplifier output signal and discriminator output pulses are fed to external devices. (author)

  19. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating, high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,at the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10 8 ―5×10 9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10 7 ―10 14 fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polari- zation and wavelength,and even quantum properties of photon.In the cascaded system of electro- magnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  20. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    LI JingZhen

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating,high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,st the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10~8-5×10~9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10~7-10~(14) fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polarization and wavelength,and even quantum properties of photon.In the cascaded system of electromagnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  1. High sensitivity amplifier/discriminator for PWC's

    International Nuclear Information System (INIS)

    The facility support group at Fermilab is designing and building a general purpose beam chamber for use in several locations at the laboratory. This pwc has 128 wires per plane spaced 1 mm apart. An initial production of 25 signal planes is anticipated. In proportional chambers, the size of the signal depends exponentially on the charge stored per unit of length along the anode wire. As the wire spacing decreases, the capacitance per unit length decreases, thereby requiring increased applied voltage to restore the necessary charge per unit length. In practical terms, this phenomenon is responsible for difficulties in constructing chambers with less than 2 mm wire spacing. 1 mm chambers, therefore, are frequently operated very near to their breakdown point and/or a high gain gas containing organic compounds such as magic gas is used. This argon/iso-butane mixture has three drawbacks: it is explosive when exposed to the air, it leaves a residue on the wires after extended use and is costly. An amplifier with higher sensitivity would reduce the problems associated with operating chambers with small wire spacings and allow them to be run a safe margin below their breakdown voltage even with an inorganic gas mixture such as argon/CO2, this eliminating the need to use magic gas. Described here is a low cost amplifier with a usable threshold of less than 0.5 μA. Data on the performance of this amplifier/discriminator in operation on a prototype beam chamber are given. This data shows the advantages of the high sensitivity of this design

  2. Feedback analysis of transimpedance operational amplifier circuits

    DEFF Research Database (Denmark)

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op......-amps is explained. It is demonstrated in a simple manner that the constant gain-bandwidth product of the conventional op-amp and the constant bandwidth of the CFB op-amp are both in accordance with basic feedback theory and that the differences between the traditional op-amp and the CFB op-amp are due to...

  3. Undulations from amplified low frequency surface waves

    International Nuclear Information System (INIS)

    We study the linear scattering of gravity waves in longitudinal inhomogeneous stationary flows. When the flow becomes supercritical, it is known that counterflow propagating shallow waves are blocked and converted into deep waves. Here we show that in the zero-frequency limit, the reflected waves are amplified in such a way that the free surface develops an undulation, i.e., a zero-frequency wave of large amplitude with nodes located at specific places. This amplification involves negative energy waves and implies that flat surfaces are unstable against incoming perturbations of arbitrary small amplitude. The relation between this instability and black hole radiation (the Hawking effect) is established

  4. Undulations from amplified low frequency surface waves

    CERN Document Server

    Coutant, Antonin

    2012-01-01

    We study the scattering of gravity waves in longitudinal stationary flows. When the flow velocity becomes supercritical, counterflow propagating waves are amplified in such a way that, in the zero-frequency limit, the free surface develops an undu- lation, i.e., a zero-frequency wave of large amplitude with nodes located at specific places. From this, we show that the unperturbed flat surface is unstable against perturbations of arbitrary small amplitude. We then show that this instability also appears when treating low frequency waves by a stochastic ensemble. The relation between the generation of undulations and black hole radiation (the Hawking effect) is discussed.

  5. Envelope tracking power amplifiers for wireless communications

    CERN Document Server

    Wang, Zhancang

    2014-01-01

    Envelope tracking technology is seen as the most promising efficiency enhancement technology for RF power amplifiers for 4G and beyond wireless communications. More and more organizations are investing and researching on this topic with huge potential in academic and commercial areas.This is the first book on the market to offer complete introduction, theory, and design considerations on envelope tracking for wireless communications. This resource presents you with a full introduction to the subject and covers underlying theory and practical design considerations.

  6. Development of 3 kW at 325 MHz solid-state RF power amplifier using four power amplifier modules

    Science.gov (United States)

    Ramarao, B. V.; Sonal, S.; Mishra, J. K.; Pande, M.; Singh, P.; Kumar, G.; Mukherjee, J.

    2014-01-01

    A high power solid-state RF power amplifier of 3 kW at 325 MHz has been developed using only four RF power amplifier modules of 850 W power output each. The design and characterization of RF power modules have been presented. A four way Wilkinson power combiner adds the output of four power amplifier modules with a total transmission loss of less than 6%. The combined power amplifier has a power gain of 20.2 dB at 1-dB compression point, and the corresponding output power is 2.8 kW at 325 MHz. The drain efficiency of the power amplifier is 65.3% at 3 kW. All the harmonics of this amplifier are below -40 dBc. The amplifier has better characteristics like fewer numbers of active devices per kilo watt, high efficiency, high gain, and ruggedness etc for RF accelerator applications.

  7. Silicon on Insulator MESFETs for RF Amplifiers.

    Science.gov (United States)

    Wilk, Seth J; Balijepalli, Asha; Ervin, Joseph; Lepkowski, William; Thornton, Trevor J

    2010-03-01

    CMOS compatible, high voltage SOI MESFETs have been fabricated using a standard 3.3V CMOS process without any changes to the process flow. A 0.6μm gate length device operates with a cut-off frequency of 7.3GHz and a maximum oscillation frequency of 21GHz. There is no degradation in device performance up to its breakdown voltage, which greatly exceeds that of CMOS devices on the same process. Other figures of merit of relevance to RF front-end design are presented, including the maximum stable gain and noise figure. An accurate representation of the device in SPICE has been developed using the commercially available TOM3 model. Using the SOI MESFET model, a source degenerated low noise RF amplifier targeting operation near 1GHz has been designed. The amplifier was fabricated on a PCB board and operates at 940MHz with a minimum NF of 3.8dB and RF gain of 9.9dB while only consuming 5mW of DC power. PMID:20657816

  8. 35 GHz gyroklystron amplifier development at NRL

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.J. [Science Applications International Corp., McLean, VA (United States); Ganguly, A.K. [Omega-P, Inc., New Haven, CT (United States); Blank, M. [Naval Research Lab., Washington, DC (United States). Vacuum Electronics Branch] [and others

    1996-12-31

    Experiments on a two-cavity gyroklystron are underway to demonstrate a 140 kW, 35 GHz gyroklystron amplifier, operating at a fundamental beam cyclotron mode and a TE{sub 011} cylindrical cavity mode. A high power electron beam of 70 kV, 6.6A is produced from a magnetron-injection-gun which is optimally designed for the TE{sub 01} mode at 35 GHz. Drift tubes consisting of lossy ceramic rings (80% BeO, 20% SiC) are designed to suppress undesired oscillations. A drive power is injected into the first cavity through a multi-hole coaxial coupler. A capacitive probe is placed directly before the input cavity to measure the beam velocity ratio. Large signal nonlinear calculations predict a peak efficiency of 30% (extracted power = 140 kW) and a saturated gain of 20dB over a 0.3% bandwidth at {alpha} = 1.5, {Delta}v{sub z}/v{sub z} = 20% at 13.3 kG and Q{sub 1} = Q{sub 2} = 200. Design parameters and initial hot-test results of the amplifier will be presented.

  9. 35 GHz, 4-Cavity Gyroklystron Amplifier Experiment

    Science.gov (United States)

    Garven, M.; Calame, J. P.; Danly, B. G.; Levush, B.; Wood, F.

    1998-11-01

    Gyroklystron amplifiers operating in the Ka-band are attractive sources for the next generation of millimeter wave radars and are currently under investigation at the Naval Research Laboratory (NRL). A four-cavity, 35 GHz gyroklystron experiment has been designed to demonstrate higher saturated gain (50dB) than previous experiments at NRL( J. J. Choi et al, IEEE Trans. Plasma Sci. 26(3), 416, 1998.). Non-linear, time-dependent simulations of the 4-cavity gyroklystron amplifier design using MAGYKL(P. E. Latham et al IEEE Trans. Plasma Sci. 22, 804, 1994.) predict 35% efficiency, 225 kW peak power, 50 dB saturated gain and a -3 dB bandwidth of 0.6%. For this four-cavity gyroklystron, the interaction between the TE_01 mode and a 70 kV, 9 A electron beam was studied with α=1.3 and an rms perpendicular velocity spread of 9%. Initial studies have shown that variations in magnetic field and voltage affect the trade-offs between power, bandwidth and efficiency. Theoretical design studies and experimental progress will be presented.

  10. Ultrastable low-noise current amplifier

    CERN Document Server

    Drung, Dietmar; Becker, Ulrich; Scherer, Hansjörg; Ahlers, Franz Josef

    2014-01-01

    An ultrastable low-noise current amplifier (ULCA) is presented. The ULCA is a non-cryogenic instrument based on specially designed operational amplifiers and resistor networks. It involves two stages, the first providing a 1000-fold current gain and the second performing a current-to-voltage conversion via an internal 1 MOhm reference resistor or, optionally, an external standard resistor. The ULCA's transfer coefficient is extremely stable versus time, temperature and current amplitude within the full dynamic range of +/-5 nA. A low noise level of 2.4 fA/sqrt(Hz) helps to keep averaging times low at small input currents. A cryogenic current comparator is used to calibrate both input current gain and output transresistance, providing traceability to the quantum Hall effect. Typically, within one day after calibration, the uncertainty contribution from short-term fluctuations of the transresistance is below one part in 10^7. The long-term stability is expected to be better than one part in 10^5 over a year. A ...

  11. ANALYSIS OF INTERNALLY GENERATED NOISE OF BIOELECTRIC AMPLIFIERS

    Institute of Scientific and Technical Information of China (English)

    Mashhour Mustafa; Bani Amer

    2003-01-01

    This paper deals with internally generated noise of bioelectric amplifiers that are usually used for processing of bioelectric events. The main purpose of this paper is to present a procedure for analysis of the effects of internal noise generated by the active circuits and to evaluate the output noise of the author's new designed bioelectric amplifier that caused by internal effects to the amplifier circuit itself in order to compare it with the noise generated by conventional amplifiers. The obtained analysis results of internally generated noise showed that the total output noise of bioelectric active circuits does not increase when some of their resistors have a larger value. This behavior is caused by the different transfer functions for the signal and the respective noise sources associated with these resistors. Moreover, the new designed bioelectric amplifier has an output noise less than that for conventional amplifiers. The obtained analysis results were also experimentally verified and the final conclusions were drawn.

  12. Gender Differences on the Use of Amplifiers in Academic Writings

    Institute of Scientific and Technical Information of China (English)

    申利芬

    2012-01-01

      This study aims to investigate the use of amplifiers in term of gender and disciplinary groups in academic research arti⁃cles, which is based on the British Academic Written English Corpus (BAWE).18 amplifiers were examined across two dimen⁃sions:gender and disciplinary groups. The results show amplifiers are more common in males’ academic writings than in those of females in general, amplifiers are used more often in AH discipline. However, not all amplifiers show significant gender differ⁃ences between men and women. Six words show a significant difference between male and female writers:pretty, by far, perfect⁃ly, quite, a great deal, totally, which are used more often by males. However, the interesting is in LS discipline, most amplifiers are used more often by female than male writers and males tend to use by far more frequently than females.

  13. Self-bias technique improves amplifier gain and noise figure

    Science.gov (United States)

    Fithian, Michael J.

    1988-05-01

    A nover self-bias technique, which provides optimum amplifier performance from low-noise GaAs FET amplifiers, is described. The self-bias scheme employs small thin-film substrates to mount packaged FETs to amplifier's main microstrip substrates. The substrates, which feature high dielectric constant, are placed under each FET source lead. The use of self-biased amplifiers results in several benefits. Thus, with a single bias supply, proper bias sequencing is not requried among amplifier stages; in a self-bias layout, the active devices are not damaged by a bias-supply failure; finally, proper self-biasing is not complex, requiring only two resistors per stage. The results of an experimental testing of the self-bias technique, evaluated for a 5.0 to 5.6 GHz low-noise amplifier with the aid of commercially available CAD software, are presented.

  14. Measurement of microdosimetric spectra using an amplifier with logarithmic response

    International Nuclear Information System (INIS)

    A 3-1/2 decade logarithmic pulse amplifier was developed for use in microdosimetry. A block diagram of the instrument is given. The input shaping amplifier is designed to accept output pulses from a charge sensitive preamplifier with a maximum full scale amplitude of 8 volts. Output of the shaping amplifier is a bipolar, positive lobe leading RC shaped pulse with a maximum linear range approximately 200 millivolts. Following the logarithmic converter is a voltage amplifier which is used to increase the signal level before it is applied through the linear gate to the output buffer-amplifier. The signal at the output connector is a positive pulse compatible with most conventional pulse height analyzers. The gain of the linear amplifier is adjustable over 10 to 1 range by means of front panel controls

  15. Acid evaporation property in chemically amplified resists

    Science.gov (United States)

    Hashimoto, Shuichi; Itani, Toshiro; Yoshino, Hiroshi; Yamana, Mitsuharu; Samoto, Norihiko; Kasama, Kunihiko

    1997-07-01

    The lithographic performance of a chemically amplified resist system very much depends on the photo-generated acid structure. In a previous paper, we reported the molecular structure dependence of two typical photo-generated acids (aromatic sulfonic acid and alkyl sulfonic acid) from the viewpoints of lithographic performance and acid characteristics such as acid generation efficiency, acid diffusion behavior and acid evaporation property. In this paper, we evaluate the effect of the remaining solvent in a resist film on the acid evaporation property. Four types of two-component chemically amplified positive KrF resists were prepared consisting of tert-butoxycarbonyl (t-BOC) protected polyhydroxystyrene and sulfonic acid derivative photo-acid generator (PAG). Here, a different combination of two types of PAGs [2,4-dimethylbenzenesulfonic acid (aromatic sulfonic acid) derivative PAG and cyclohexanesulfonic acid (alkyl sulfonic acid) derivative PAG] and two types of solvents (propylene glycol monomethyl ether acetate; PGMEA and ethyl lactate; EL) were evaluated. The aromatic sulfonic acid was able to evaporate easily during post exposure bake (PEB) treatment, but the alkyl sulfonic acid was not. The higher evaporation property of aromatic sulfonic acid might be due to the higher vapor pressure and the longer acid diffusion length. Furthermore, the amount of aromatic sulfonic acid in the PGMEA resist was reduced by more than that in the EL resist. The amount of acid loss also became smaller at a higher prebake temperature. The concentration of the remaining solvent in the resist film decreased with the increasing prebake temperature. We think that the acid evaporation property was affected by the remaining solvent in the resist, film; the large amount of remaining solvent promoted the acid diffusion and eventually accelerated the acid evaporation from the resist film surface in the PGMEA resist. In summary, the acid evaporation property depends on both the acid

  16. Direct coupled amplifiers using field effect transistors

    International Nuclear Information System (INIS)

    The concept of the uni-polar field effect transistor (P.E.T.) was known before the invention of the bi-polar transistor but it is only recently that they have been made commercially. Being produced as yet only in small quantities, their price imposes a restriction on use to circuits where their peculiar properties can be exploited to the full. One such application is described here where the combination of low voltage drift and relatively low input leakage current are necessarily used together. One of the instruments used to control nuclear reactors has a logarithmic response to the mean output current from a polarised ionisation chamber. The logarithmic signal is then differentiated electrically, the result being displayed on a meter calibrated to show the reactor divergence or doubling time. If displayed in doubling time the scale is calibrated reciprocally. Because of the wide range obtained in the logarithmic section and the limited supply voltage, an output of 1 volt per decade change in ionisation current is used. Differentiating this gives a current of 1.5 x 10-8 A for p.s.D. (20 sec. doubling time) in the differentiating amplifier. To overcome some of the problems of noise due to statistical variations in input current, the circuit design necessitates a resistive path to ground at the amplifier input of 20 M.ohms. A schematic diagram is shown. 1. It is evident that a zero drift of 1% can be caused by a leakage current of 1.5 x 10-10 A or an offset voltage of 3 mV at the amplifier input. Although the presently used electrometer valve is satisfactory from the point of view of grid current, there have been sudden changes in grid to grid voltage (the valve is a double triode) of up to 10 m.V. It has been found that a pair of F.E.T's. can be used to replace the electrometer valve so long as care is taken in correct balance of the two devices. An investigation has been made into the characteristics of some fourteen devices to see whether those with very different

  17. Thermodynamic indistinguishability and field state fingerprint of quantum optical amplifiers

    OpenAIRE

    Perl, Yossi; Band, Yehuda B.; Boukobza, Erez

    2016-01-01

    Dissipation tends to wash out dynamical features observed at early evolution times. In this paper we analyze a resonant single--atom two--photon quantum optical amplifier both dynamically and thermodynamically. A detailed thermodynamic balance shows that the non--linear amplifier is thermodynamically equivalent to the linear amplifier discussed in (Phys. Rev. A, 74 (2006), 063822). However, by calculating the Wigner quasi--probability distribution for various initial field states, we show tha...

  18. A high performance switching audio amplifier using sliding mode control

    OpenAIRE

    Pillonnet, Gael; Cellier, Rémy; Abouchi, Nacer; Chiollaz, Monique

    2008-01-01

    International audience The switching audio amplifiers are widely used in various portable and consumer electronics due to their high efficiency, but suffers from low audio performances due to inherent nonlinearity. This paper presents an integrated class D audio amplifier with low consumption and high audio performances. It includes a power stage and an efficient control based on sliding mode technique. This monolithic class D amplifier is capable of delivering up to 1W into 8Ω load at les...

  19. Design and experimental investigation of charge amplifiers for ultrasonic transducers

    OpenAIRE

    Hansen, Svein Kristian Esp

    2014-01-01

    Amplifiers are used in all types of electrical circuits to boost signal and there is a huge variety in designs used for different applications. For ultrasonic applications our group has previously used commercial available transimpedance amplifiers that converts a current to a voltage, but these amplifiers have a linear response over its frequency range. To preserve as much information as possible for lower frequencies a flat frequency response is preferable. The main goa...

  20. Modeling and design techniques for RF power amplifiers

    CERN Document Server

    Raghavan, Arvind; Laskar, Joy

    2008-01-01

    The book covers RF power amplifier design, from device and modeling considerations to advanced circuit design architectures and techniques. It focuses on recent developments and advanced topics in this area, including numerous practical designs to back the theoretical considerations. It presents the challenges in designing power amplifiers in silicon and helps the reader improve the efficiency of linear power amplifiers, and design more accurate compact device models, with faster extraction routines, to create cost effective and reliable circuits.

  1. A Review of High Voltage Drive Amplifiers for Capacitive Actuators

    DEFF Research Database (Denmark)

    Huang, Lina; Zhang, Zhe; Andersen, Michael A. E.

    2012-01-01

    This paper gives an overview of the high voltage amplifiers, which are used to drive capacitive actuators. The amplifiers for both piezoelectric and DEAP (dielectric electroactive polymer) actuator are discussed. The suitable topologies for driving capacitive actuators are illustrated in detail......, including linear as well as switched mode amplifiers. In the past much attention has been paid on the driver for piezoelectric actuator. As DEAP is a type of new material, there is not much literature reference for it....

  2. Design of a Broadband Amplifier for High Speed Applications

    OpenAIRE

    Camargo, E.; Virk, R.S.; Hajji, R.; Parker, S; Ohnishi, H

    2002-01-01

    This paper provides comprehensive insight into the design approach followed for an amplifier dedicated to high speed base band signals. To demonstrate the methodology, an amplifier consisting of nine PHEMT cascode cells within a distributed amplifier topology was designed. The resulting frequency response is 40 GHz at the 3-dB point, and the output voltage for a 43 Gbps eye diagram is 7.3 Vpp at the chip terminal.

  3. InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz

    Science.gov (United States)

    Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, William; Dang, Linh; Li, Danny; Cavus, Abdullah; To, Richard; Lai, Richard

    2009-01-01

    Two single-stage InP heterojunction bipolar transistor (HBT) amplifiers operate at 184 and 255 GHz, using Northrop Grumman Corporation s InP HBT MMIC (monolithic microwave integrated circuit) technology. At the time of this reporting, these are reported to be the highest HBT amplifiers ever created. The purpose of the amplifier design is to evaluate the technology capability for high-frequency designs and verify the model for future development work.

  4. The spectacular human nose: An amplifier of individual quality?

    OpenAIRE

    Åse Kristine Rognmo Mikalsen; Ivar Folstad; Nigel Gilles Yoccoz; Bruno Laeng

    2014-01-01

    Amplifiers are signals that improve the perception of underlying differences in quality. They are cost free and advantageous to high quality individuals, but disadvantageous to low quality individuals, as poor quality is easier perceived because of the amplifier. For an amplifier to evolve, the average fitness benefit to the high quality individuals should be higher than the average cost for the low quality individuals. The human nose is, compared to the nose of most other primates, extraordi...

  5. The solid-state Ku-band power amplifier

    Science.gov (United States)

    Geller, B. D.

    1975-01-01

    A survey of IMPATT diodes and negative resistance amplifiers is presented. The first phase of the amplifier effort is discussed in which a single diode reflection amplifier delivering 0.5 watt at 15 GHz with 10-dB gain over a 1-GHz band was developed. The design of a dominant mode resonant combiner is described along with the characterization of the IMPATT diodes. Results are given on the complete amplifier and on the thermal and graceful failure characteristics of the unit.

  6. Pulse-distortion in a quantum-dot optical amplifier

    DEFF Research Database (Denmark)

    Romstad, Francis Pascal; Borri, Paola; Mørk, Jesper; Hvam, Jørn Märcher; Heinrichsdorff, F.; Mao, M.-H.; Bimberg, Dieter

    2000-01-01

    Distortion of a -150fs optical pulse after propagation through an InAs/InGaAs quantum-dot optical amplifier is measured for different input energies an bias currents. Pulse distortion is observed and compared with results on a bulk amplifier.......Distortion of a -150fs optical pulse after propagation through an InAs/InGaAs quantum-dot optical amplifier is measured for different input energies an bias currents. Pulse distortion is observed and compared with results on a bulk amplifier....

  7. Parametric Amplifiers for Microwave Kinectic Inductance Detector (MKID) Readout Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Find numerical solutions to the non-linear partial differential equations describing our amplifier transmission lines. Optimize periodic choke structure to block...

  8. Multi Carrier Modulation Audio Power Amplifier with Programmable Logic

    DEFF Research Database (Denmark)

    Christiansen, Theis; Andersen, Toke Meyer; Knott, Arnold;

    2009-01-01

    amplifiers while keeping the performance measures to excellent levels is therefore of high interest. In this paper a class D audio amplifier utilising Multi Carrier Modulation (MCM) will be analysed, and a prototype Master-Slave Multi Carrier Modulated (MS MCM) amplifier has been constructed and measured for...... performance and out of band spectral amplitudes. The basic principle in MCM is to use programmable logic to combine two or more Pulse Width Modulated (PWM) audio signals at different switching frequencies. In this way the out of band spectrum will be lowered compared with conventional class D amplifiers...

  9. Design of Class-E Radio Frequency Power Amplifier

    OpenAIRE

    Al-Shahrani, Saad Mohammed

    2000-01-01

    Power amplifiers (PA) are typically the most power-consuming building blocks of RF transceivers. Therefore, the design of a high-efficiency radio frequency power amplifier is the most obvious solution to overcoming the battery lifetime limitation in the portable communication systems. A power amplifierà ­s classes (A, AB, B, C, F, E, etc), and design techniques (Load-pull and large-signal S-parameters techniques) are presented. The design accuracy of class-A power amplifier based on the s...

  10. Modeling a Common-Source Amplifier Using a Ferroelectric Transistor

    Science.gov (United States)

    Sayyah, Rana; Hunt, Mitchell; MacLeond, Todd C.; Ho, Fat D.

    2010-01-01

    This paper presents a mathematical model characterizing the behavior of a common-source amplifier using a FeFET. The model is based on empirical data and incorporates several variables that affect the output, including frequency, load resistance, and gate-to-source voltage. Since the common-source amplifier is the most widely used amplifier in MOS technology, understanding and modeling the behavior of the FeFET-based common-source amplifier will help in the integration of FeFETs into many circuits.

  11. Controlling the dynamic range of a Josephson parametric amplifier

    International Nuclear Information System (INIS)

    One of the central challenges in the development of parametric amplifiers is the control of the dynamic range relative to its gain and bandwidth, which typically limits quantum limited amplification to signals which contain only a few photons per inverse bandwidth. Here, we discuss the control of the dynamic range of Josephson parametric amplifiers by using Josephson junction arrays. We discuss gain, bandwidth, noise, and dynamic range properties of both a transmission line and a lumped element based parametric amplifier. Based on these investigations we derive useful design criteria, which may find broad application in the development of practical parametric amplifiers. (orig.)

  12. Operational characteristics of the NRL gyroklystron amplifier

    International Nuclear Information System (INIS)

    The high-energy physics community is considering the development of 1 TeV accelerators. Size and cost of such devices can be greatly reduced by operating at 10 GHz. Present tube technology seems incapable of meeting the power requirements at this frequency. A strong candidate for a drive tube to meet these requirements is a gyroklystron amplifier (GKA) due to its high gain, efficiency and power capabilities. The Naval Research Laboratory (NRL) is presently conducting GKA research to evaluate their performance characteristics. Operation of a 54 kW, 30% efficient, 4.5 GHz 3-cavity GKA is described. Experiments to evaluate the effects on the output phase of varying drive voltage, beam current, magnetic field and drive power and to examine phase-locked oscillator performance are discussed. The results of present GKA experiments serve to emphasize the applicability of the GKA to the next generation of linear accelerators

  13. CARM-klystron amplifier for accelerator applications

    Science.gov (United States)

    Gold, Steven H.; Fliflet, Arne W.

    2001-05-01

    We consider the possibility of a cyclotron-autoresonance-maser (CARM) klystron configuration for accelerator applications as an alternative to the gyroklystron amplifier. The potential advantages, compared to gyroklystrons, include: 1) comparable efficiencies at lower values of the electron beam pitch ratio α, which should improve the beam quality and make the device substantially more stable against the excitation of parasitic mode, 2) operation far from cutoff, which should reduce the fields at cavity walls, allowing higher power operation, and 3) operation at lower magnetic fields for the same cyclotron harmonic number. However, there are two significant issues associated with the design of efficient, high-power CARMs. First, because of the higher value of kZ, compared to gyroklystrons, CARMs are substantially more sensitive to parallel velocity spread (pitch-angle spread). Second, conventional cavities support a variety of near-cutoff modes, which can compete with the CARM interaction. Therefore, one must consider either Bragg resonators or quasioptical cavity configurations.

  14. Gain Characteristics of Fiber Optical Parametric Amplifier

    Institute of Scientific and Technical Information of China (English)

    高明义; 姜淳; 胡卫生

    2004-01-01

    The theory model of fiber optical parametric amplifier (FOPA) was introduced, which is based on optical nonlinear effect. And then numerical simulation was done to analyze and discuss the gain spectral characteristics of one-pump and two-pump FOPA. The results show that for one-pump FOPA, when pump wavelength is near to fiber zero-dispersion wavelength(ZDW), the gain flatness is better, and with the increase of the pump power, fiber length and its nonlinear coefficient, the gain value will increase while the gain bandwidth will become narrow. For two-pump FOPA, when the pump central wavelength is near to fiber ZDW, the gain flatness is better. Moreover, by decreasing the space of two pumps wavelength, the gain flatness can be improved. Finally, some problems existing in FOPA were addressed.

  15. New developments in relativistic klystron amplifiers

    International Nuclear Information System (INIS)

    A relativistic klystron amplifier that employed cavities with inductively loaded wide gaps and a novel converter has achieved 50% energy efficiency, a significant advance over the previous state of the art of 20%. The new device was immersed in a 3 kG magnetic field and contained two innovations: (1) Wide gaps which include an inductively loaded return current structure that was opaque to the unmodulated beam space charge but transparent to the RF field. (2) A novel converter that was made of a 'leaky' cavity with a radially-converging inductively-loaded structure that was inserted in the output wide-gap. This structure reduced the potential energy residing in the electron beam and maximized RF output energy. (author). 4 figs., 13 refs

  16. Current feedback operational amplifiers and their applications

    CERN Document Server

    Senani, Raj; Singh, A K; Singh, V K

    2013-01-01

    This book describes a variety of current feedback operational amplifier (CFOA) architectures and their applications in analog signal processing/generation. Coverage includes a comprehensive survey of commercially available, off-the-shelf integrated circuit CFOAs, as well as recent advances made on the design of CFOAs, including design innovations for bipolar and CMOS CFOAs.  This book serves as a single-source reference to the topic, as well as a catalog of over 200 application circuits which would be useful not only for students, educators and researchers in apprising them about the recent developments in the area but would also serve as a comprehensive repertoire of useful circuits for practicing engineers who might be interested in choosing an appropriate CFOA-based topology for use in a given application.

  17. High-energy regenerative thin disk amplifier

    Czech Academy of Sciences Publication Activity Database

    Chyla, Michal; Smrž, Martin; Mocek, Tomáš

    Melville: AIP, 2012 - (Osvay, K.; Dombi, P.; Fülöp, J.; Varjú, K.), s. 84-87. (AIP Conference Proceedings. 1462). ISBN 978-0-7354-1066-4. ISSN 0094-243X. [Light at Extreme Intensities 2011. Szeged (HU), 14.11.2011-18.11.2011] R&D Projects: GA MŠk ED1.1.00/02.0061; GA MŠk ED2.1.00/01.0027 Grant ostatní: ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; HILASE(XE) CZ.1.05/2.1.00/01.0027 Institutional support: RVO:68378271 Keywords : Yb: YAG * thin-disk * regenerative amplifier * high energy * picosecond pulses * CPA Subject RIV: BH - Optics, Masers, Lasers

  18. Cryogenic cooling for high power laser amplifiers

    International Nuclear Information System (INIS)

    The Extreme Light Infrastructure (ELI) will be a new scientific European infrastructure devoted to scientific research in lasers field, dedicated to the investigation and applications of laser-matter interaction at the highest intensity level (more than 6 orders of magnitude higher than today’s laser intensity). The ELI project, a collaboration of 13 European countries, will comprise three branches: Ultra High Field Science that will explore laser-matter interaction, attosecond Laser Science designed to conduct temporal investigation of electron dynamics in atoms, molecules, plasmas and solids at attosecond scale, High Energy Beam Science devoted to the development and usage o f dedicated beam lines with ultra short pulses of high energy radiation. Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-cIass lasers with enhanced repetition rates are developed. Each of the Yb YaG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz), The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100K-170K with a heat flux of 1 MW*m-2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser. (author)

  19. Cryogenic cooling for high power laser amplifiers

    International Nuclear Information System (INIS)

    The Extreme Light Infrastructure (ELI) will be a new scientific European infrastructure devoted to scientific research in lasers field, dedicated to the investigation and applications of laser-matter interaction at the highest intensity level (more than 6 orders of magnitude higher than today's laser intensity). The ELI project, a collaboration of 13 European countries, will comprise three branches: Ultra High Field Science that will explore laser-matter interaction, atto-second Laser Science designed to conduct temporal investigation of electron dynamics in atoms, molecules, plasmas and solids at atto-second scale, High Energy Beam Science devoted to the development and usage of dedicated beam lines with ultra short pulses of high energy radiation. Using DPSSL (Diode Pumped Solid State Lasers) as pumping technology, PW-class lasers with enhanced repetition rates are developed. Each of the Yb YaG amplifiers will be diode-pumped at a wavelength of 940 nm. This is a prerequisite for achieving high repetition rates (light amplification duration 1 millisecond and repetition rate 10 Hz). The efficiency of DPSSL is inversely proportional to the temperature, for this reason the slab amplifier have to be cooled at a temperature in the range of 100 K-170 K with a heat flux of 1 MW.m-2. This paper describes the thermo-mechanical analysis for the design of the amplification laser head, presents a preliminary proposal for the required cryogenic cooling system and finally outlines the gain of cryogenic operation for the efficiency of high pulsed laser. (authors)

  20. Development of 3 kW at 325 MHz solid-state RF power amplifier using four power amplifier modules

    International Nuclear Information System (INIS)

    A high power solid-state RF power amplifier of 3 kW at 325 MHz has been developed using only four RF power amplifier modules of 850 W power output each. The design and characterization of RF power modules have been presented. A four way Wilkinson power combiner adds the output of four power amplifier modules with a total transmission loss of less than 6%. The combined power amplifier has a power gain of 20.2 dB at 1-dB compression point, and the corresponding output power is 2.8 kW at 325 MHz. The drain efficiency of the power amplifier is 65.3% at 3 kW. All the harmonics of this amplifier are below −40 dBc. The amplifier has better characteristics like fewer numbers of active devices per kilo watt, high efficiency, high gain, and ruggedness etc for RF accelerator applications. -- Highlights: • High gain power amplifier, power gain at 20 dB. • High efficiency amplifier, efficiency >65%. • Minimum number of modules per kilo watt power output. • Heat sink with modules on both side, high density

  1. X-Band, 17-Watt Solid-State Power Amplifier

    Science.gov (United States)

    Mittskus, Anthony; Stone, Ernest; Boger, William; Burgess, David; Honda, Richard; Nuckolls, Carl

    2005-01-01

    An advanced solid-state power amplifier that can generate an output power of as much as 17 W at a design operating frequency of 8.4 GHz has been designed and constructed as a smaller, lighter, less expensive alternative to traveling-wave-tube X-band amplifiers and to prior solid-state X-band power amplifiers of equivalent output power. This amplifier comprises a monolithic microwave integrated circuit (MMIC) amplifier module and a power-converter module integrated into a compact package (see Figure 1). The amplifier module contains an input variable-gain amplifier (VGA), an intermediate driver stage, a final power stage, and input and output power monitors (see Figure 2). The VGA and the driver amplifier are 0.5-m GaAs-based metal semiconductor field-effect transistors (MESFETs). The final power stage contains four parallel high-efficiency, GaAs-based pseudomorphic high-electron-mobility transistors (PHEMTs). The gain of the VGA is voltage-variable over a range of 10 to 24 dB. To provide for temperature compensation of the overall amplifier gain, the gain-control voltage is generated by an operational-amplifier circuit that includes a resistor/thermistor temperature-sensing network. The driver amplifier provides a gain of 14 dB to an output power of 27 dBm to drive the four parallel output PHEMTs, each of which is nominally capable of putting out as much as 5 W. The driver output is sent to the input terminals of the four parallel PHEMTs through microstrip power dividers; the outputs of these PHEMTs are combined by microstrip power combiners (which are similar to the microstrip power dividers) to obtain the final output power of 17 W.

  2. Externally pumped millimeter-wave Josephson-junction parametric amplifier

    DEFF Research Database (Denmark)

    Levinsen, M.T; Pedersen, Niels Falsig; Sørensen, Ole;

    1980-01-01

    A unified theory of the singly and doubly degenerate Josephson-junction parametric amplifier is presented. Experiments with single junctions on both amplifier modes at frequencies 10, 35, and 70 GHz are discussed. Low-noise temperature (∼100 K, single sideband (SSB)) and reasonable gain (∼8 dB) w...

  3. Solid-State Power Amplifier For 61.5 GHz

    Science.gov (United States)

    Powers, Michael K.; Mcclymonds, James; Vye, David; Arthur, Thomas

    1992-01-01

    Power amplifiers based on impact-avalanche-transit-time (IMPATT) diodes developed for operation in communication systems at frequencies near 60 GHz. Built in seven modular stages, power transferred through sections of waveguide and isolator/circulator assemblies. Intended as replacements for bulkier and heavier traveling-wave-tube amplifiers.

  4. CARM and harmonic gyro-amplifier experiments at 17 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Menninger, W.L.; Danly, B.G.; Alberti, S.; Chen, C.; Rullier, J.L.; Temkin, R.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States). Plasma Fusion Center; Giguet, E. [Massachusetts Inst. of Technology, Cambridge, MA (United States). Plasma Fusion Center]|[Thomson Tubes Electroniques, Velizy (France)

    1993-11-01

    Cyclotron resonance maser amplifiers are possible sources for applications such as electron cyclotron resonance heating of fusion plasmas and driving high-gradient rf linear accelerators. For accelerator drivers, amplifiers or phase locked-oscillators are required. A 17 GHz cyclotron autoresonance maser (CARM) amplifier experiment and a 17 GHz third harmonic gyro-amplifier experiment are presently underway at the MIT Plasma Fusion Center. Using the SRL/MIT SNOMAD II introduction accelerator to provide a 380 kV, 180 A, 30 ns flat top electron beam, the gyro-amplifier experiment has produced 5 MW of rf power with over 50 dB of gain at 17 GHz. The gyro-amplifier operates in the TE{sub 31} mode using a third harmonic interaction. Because of its high power output, the gyro-amplifier will be used as the rf source for a photocathode rf electron gun experiment also taking place at MIT. Preliminary gyro-amplifier results are presented, including measurement of rf power, gain versus interaction length, and the far-field pattern. A CARM experiment designed to operate in the TE{sub 11} mode is also discussed.

  5. Phase Sensitive Amplifier Based on Ultrashort Pump Pulses

    CERN Document Server

    Gershikov, Alexander

    2016-01-01

    We demonstrate a narrow band phase sensitive amplifier in the pump degenerate configuration which employs ps pump pulses. Control of the amplifier bandwidth is achieved via changes of the pump spectral width. A phase sensitive gain between -6 and 6 decibels, with an overall system gain of 28dB was demonstrated.

  6. Design of vortex fluid amplifiers with asymmetrical flow fields.

    Science.gov (United States)

    Lawley, T. J.; Price, D. C.

    1972-01-01

    Variation of geometric parameters, including supply area, control area, chamber length, and outlet diameter, of a large scale, modular design vortex fluid amplifier with single supply and control jets, has confirmed and extended a previously published design method, developed for vortex amplifiers with symmetric flow fields. This allows application of the method to devices which are more representative of practical, production type components.

  7. Gain characteristics of a saturated fiber optic parametric amplifier

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Lorenzen, Michael Rodas; Noordegraaf, Danny;

    2008-01-01

    In this work we discuss saturation performance of a fiber optic parametric amplifier. A simple numerical model is described and applied to specific cases. A system experiment using a saturated amplifier illustrates a 4 dB improvement in required signal to noise ratio for a fixed bit error ratio....

  8. Optically amplifying planar glass waveguides: Laser on a chip

    DEFF Research Database (Denmark)

    Guldberg-Kjær, Søren Andreas

    The objective of this work was to devlop optically amplifying planar wavguides, using erbium-doped germano-silicate glass films deposited by PECVD (Plasma Enhanced Chemical Vapour Deposition). The waveguides should exhibit enough gain to be useful as optical amplifiers in integrated planar lightw...

  9. Band-Pass Amplifier Without Discrete Reactance Elements

    Science.gov (United States)

    Kleinberg, L.

    1984-01-01

    Inherent or "natural" device capacitance exploited. Band-Pass Circuit has input impedance of equivalent circuit at frequencies much greater than operational-amplifier rolloff frequency. Apparent inductance and capacitance arise from combined effects of feedback and reactive component of amplifier gain in frequency range.

  10. A high performance electrometer amplifier of hybrid design

    International Nuclear Information System (INIS)

    A high performance, reliable, electrometer amplifier of hybrid design for low current measurements in mass spectrometers has been developed. The short term instability with a 5 x 1011 ohms input resistor is less than 1 x 10sup(-15) Amp. The drift is better than 1 mV/hour. The design steps are illustrated with a typical amplifier performance details. (auth.)

  11. Saturation and noise properties of quantum-dot optical amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2004-01-01

    Based on extensive numerical calculations, quantum-dot (QD) amplifiers are predicted to offer higher output power and lower noise figure compared to bulk as well as quantum well amplifiers. The underlying physical mechanisms are analyzed in detail, leading to the identification of a few key...

  12. Ultrafast Dynamics of Quantum-Dot Semiconductor Optical Amplifiers

    DEFF Research Database (Denmark)

    Poel, Mike van der; Hvam, Jørn Märcher

    2007-01-01

    We report on a series of experiments on the dynamical properties of quantum-dot semiconductor optical amplifiers. We show how the amplifier responds to one or several ultrafast (170 fs) pulses in rapid succession and our results demonstrate applicability and ultimate limitations to application of...

  13. Subjective test of class D amplifiers without output filter

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Fenger, Lars M.

    2004-01-01

    This paper presents the results of subjective listening tests designed to determine whether the output filter on class D amplifiers used in active loudspeakers can be omitted without audible errors occurring. The frequency range of the amplifiers was limited to 0-3 kHz corresponding to a woofer...

  14. Advances in Solid Core Photonic Bandgap Fiber Amplifiers

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Laurila, Marko; Petersen, Sidsel Rübner;

    2012-01-01

    We present recent development of photonic crystal fiber amplifiers containing photonic bandgap structures for enhanced spectral and modal filtering functionality.......We present recent development of photonic crystal fiber amplifiers containing photonic bandgap structures for enhanced spectral and modal filtering functionality....

  15. Switching-mode Audio Power Amplifiers with Direct Energy Conversion

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper presents a new class of switching-mode audio power amplifiers, which are capable of direct energy conversion from the AC mains to the audio output. They represent an ultimate integration of a switching-mode power supply and a Class D audio power amplifier, where the intermediate DC bus...... component count, volume and cost....

  16. Models of reduced-noise, probabilistic linear amplifiers

    Science.gov (United States)

    Combes, Joshua; Walk, Nathan; Lund, A. P.; Ralph, T. C.; Caves, Carlton M.

    2016-05-01

    We construct an amplifier that interpolates between a nondeterministic, immaculate linear amplifier and a deterministic, ideal linear amplifier and beyond to nonideal linear amplifiers. The construction involves cascading an immaculate linear amplifier that has amplitude gain g1 with a (possibly) nonideal linear amplifier that has gain g2. With respect to normally ordered moments, the device has output noise μ2(G2-1 ) where G =g1g2 is the overall amplitude gain and μ2 is a noise parameter. When μ2≥1 , our devices realize ideal (μ2=1 ) and nonideal (μ2>1 ) linear amplifiers. When 0 ≤μ2devices work effectively only over a restricted region of phase space and with some subunity success probability p✓. We investigate the performance of our μ2 amplifiers in terms of a gain-corrected probability-fidelity product and the ratio of input to output signal-to-noise ratios corrected for success probability.

  17. Ferroelectric Field-Effect Transistor Differential Amplifier Circuit Analysis

    Science.gov (United States)

    Phillips, Thomas A.; MacLeod, Todd C.; Ho, Fat D.

    2008-01-01

    There has been considerable research investigating the Ferroelectric Field-Effect Transistor (FeFET) in memory circuits. However, very little research has been performed in applying the FeFET to analog circuits. This paper investigates the use of FeFETs in a common analog circuit, the differential amplifier. The two input Metal-Oxide-Semiconductor (MOS) transistors in a general MOS differential amplifier circuit are replaced with FeFETs. Resistors are used in place of the other three MOS transistors. The FeFET model used in the analysis has been previously reported and was based on experimental device data. Because of the FeFET hysteresis, the FeFET differential amplifier has four different operating modes depending on whether the FeFETs are positively or negatively polarized. The FeFET differential amplifier operation in the different modes was analyzed by calculating the amplifier voltage transfer and gain characteristics shown in figures 2 through 5. Comparisons were made between the FeFET differential amplifier and the standard MOS differential amplifier. Possible applications and benefits of the FeFET differential amplifier are discussed.

  18. A NIM module for efficient amplifier pile-up rejection

    International Nuclear Information System (INIS)

    A NIM standard module containing four individual circuits for detecting an amplifier pile-up condition is described. Each circuit can be adjusted to match a wide range of amplifier shaping time-constants. Output with a variable delay are provided for signaling a pile-up reject to the data acquisition system

  19. Frequency-Offset Cartesian Feedback Based on Polyphase Difference Amplifiers

    OpenAIRE

    Zanchi, Marta G.; Pauly, John M.; Scott, Greig C

    2010-01-01

    A modified Cartesian feedback method called “frequency-offset Cartesian feedback” and based on polyphase difference amplifiers is described that significantly reduces the problems associated with quadrature errors and DC-offsets in classic Cartesian feedback power amplifier control systems.

  20. CARM and harmonic gyro-amplifier experiments at 17 GHz

    International Nuclear Information System (INIS)

    Cyclotron resonance maser amplifiers are possible sources for applications such as electron cyclotron resonance heating of fusion plasmas and driving high-gradient rf linear accelerators. For accelerator drivers, amplifiers or phase locked-oscillators are required. A 17 GHz cyclotron autoresonance maser (CARM) amplifier experiment and a 17 GHz third harmonic gyro-amplifier experiment are presently underway at the MIT Plasma Fusion Center. Using the SRL/MIT SNOMAD II introduction accelerator to provide a 380 kV, 180 A, 30 ns flat top electron beam, the gyro-amplifier experiment has produced 5 MW of rf power with over 50 dB of gain at 17 GHz. The gyro-amplifier operates in the TE31 mode using a third harmonic interaction. Because of its high power output, the gyro-amplifier will be used as the rf source for a photocathode rf electron gun experiment also taking place at MIT. Preliminary gyro-amplifier results are presented, including measurement of rf power, gain versus interaction length, and the far-field pattern. A CARM experiment designed to operate in the TE11 mode is also discussed

  1. Experimental demonstration of high power millimeter wave gyro-amplifiers

    Science.gov (United States)

    Blank, M.; Garven, M.; Calame, J. P.; Choi, J. J.; Danly, B. G.; Levush, B.; Nguyen, K.; Pershing, D. E.

    1999-05-01

    The Naval Research Laboratory is currently investigating gyro-amplifiers as high power, broadband sources for millimeter wave radars. A three-cavity Ka-band gyroklystron achieved 225 kW peak output power with 0.82% bandwidth. At W-band, several multi-cavity gyro-amplifiers have been experimentally demonstrated. A four-cavity gyroklystron amplifier has achieved 84 kW peak output power at 34% efficiency with 370 MHz bandwidth. A five-cavity gyroklystron demonstrated 72 kW peak output power with 410 MHz bandwidth and 50 dB saturated gain. For applications requiring greater bandwidth, gyrotwystron amplifiers are also under study. A four section W-band gyrotwystron demonstrated 50 kW peak output power at 925 MHz bandwidth. The results of recent Ka-band and W-band gyro-amplifier experiments and comparisons of measured data with predictions of theory are presented.

  2. A 12 GHz solid state power amplifier, phase 1B

    Science.gov (United States)

    Bestwick, P. R.

    1986-05-01

    Attempts to develop a balanced amplifier developing 4 W power output at 12.6 GHz, with a gain of 3.5 dB are summarized. Calculation of the device large-signal conjugate match points, measurement of the points, design and tuning of single-ended amplifier, modules, and a bias insertion network are described. A Lange coupler and a termination for it are presented. The performance of the balanced amplifier, and that of a competing Fujitsu amplifier, are analyzed. The differences in device structure between the PRCL 4820 device and the Fujitsu device are assessed. The amplifier developed gives (at 1 dB gain compression) a gain of 2.4 dB and a power output of 3.2 dB. Difficulties stem from the use of the double-cell 4820 device, and of the Lange type quadrature couplers.

  3. Improving Students' Understanding of Lock-In Amplifiers

    CERN Document Server

    DeVore, Seth; Levy, Jeremy; Singh, Chandralekha

    2016-01-01

    The lock-in amplifier is a versatile instrument frequently used in physics research. However, many students struggle with the basic operating principles of a lock-in amplifier which can lead to a variety of difficulties. To improve students' understanding, we have been developing and evaluating a research-based tutorial which makes use of a computer simulation of a lock-in amplifier. The tutorial allows students to realize their conceptual difficulties by comparing their predictions about how a lock-in amplifier will behave with the outcome of simulated experiments. After being confronted with discrepancies between their predictions and the lock-in amplifier results, the tutorial targets the common difficulties that students have and leads them to develop a deeper understanding of the principles of lock-in amplification.

  4. Coupled Lines Filters for Broadband Impedance Matching of Microwave Amplifiers

    Directory of Open Access Journals (Sweden)

    Mohammed Lahsaini

    2014-08-01

    Full Text Available In this paper we present a broadband matching technique for the design of low noise amplifiers. This technique is based on the use of coupled lines filters and quarter wave transformers for the adaptation and stabilization of these amplifiers, presenting the theory and the design process of these circuits. The type of transistors used for modeling this amplifier is the HEMT of Alpha Industries®. The results we found show that this amplifier is unconditionally stable with a satisfactory gain of about 20 dB and good impedance matching across the band of interest [10-12] GHz. The amplifier modeled in this work can be integrated in satellite receiving systems and radar systems.

  5. Implementation of envelope tracking for RF solid state amplifiers

    Science.gov (United States)

    Larter, Thomas Leigh

    The Facility for Rare Isotope Beams (FRIB) is currently in its development stages at Michigan State University. The facility uses a large linear accelerator system to accelerate ionized particles which are then collided with other particles in the hopes of finding rare isotopes of elements. This accelerating action depends on several systems to function, with one of the major systems being superconducting cavity structures. These cavities are driven by high-power RF amplifiers which account for a large portion of the accelerator's power consumption. It is important to maximize the efficiency of these amplifiers in order to keep energy costs for the facility low. One of the ways to increase efficiency is to choose an amplifier topology that is highly efficient. A study was done for FRIB testing the prospect of using amplifiers with the envelope tracking (ET) topology. An amplifier's efficiency relies on its output power and the power supplied to it, which are in turn directly related to the output signal voltage and supply rail voltage. In an ET RF amplifier, the supply voltage is made to closely follow the envelope of the output signal voltage. This tracking action allows the RF amplifier to operate with much improved efficiency at low power levels and nearly constant efficiency at high power levels. The ET tests performed for FRIB attempted to verify the validity of ET efficiency gains for RF amplifiers. These tests included the characterization of an RF amplifier, development and verification of an ET control algorithm, and implementation of an ET test bench using FRIB equipment. These tests should attest to the purported increase in efficiency possible with ET and prove that the power consumption budget for the FRIB will benefit from the use of such amplifiers.

  6. A solid hydraulically amplified piezoelectric microvalve

    International Nuclear Information System (INIS)

    We report a piezoelectrically driven and hydraulically amplified axial polymer microvalve. The microvalve is normally open and is assembled primarily with stereolithographically fabricated polymer components. An incompressible elastomer is used as a solid hydraulic medium to convert the small axial displacement of a piezoelectric actuator into a large valve head stroke while maintaining a large blocking force. Also, the axial design of the microvalve enables densely packed valve arrays. One application of this microvalve is in pneumatic tactile displays, which operates against gas pressure up to approximately 90 kPa and switching speed between 1 and 200 Hz. The current valve design has a maximum static hydraulic amplification ratio of 5 at 30 V driving voltage and a maximum valve head stroke of 37 µm at 150 V. Under a 94.4 kPa differential pressure, the flow rate of the valve and the closing voltage measure are 785 mL min−1 and 150 V, respectively. The function of the microvalve as an on–off switch for a pneumatic microbubble tactile actuator is demonstrated

  7. Efficient and Compact Optical Amplifier Using EYDF

    Directory of Open Access Journals (Sweden)

    Sulaiman Wadi Harun

    2010-09-01

    Full Text Available An efficient Erbium/Ytterbium doped fiber amplifier (EYDFA is demonstrated using a 1058nm pumping wavelength, where the amplification is assisted by energy transfer between Yb and Er ions. The energy transfer increases the limit of erbium doping concentration that is imposed by concentration quenching in Erbium-doped fiber (EDF. Therefore, the gain and noise figure are severely degraded with 1480 nm pumping, where the energy transfer cannot be achieved. The use of optical isolator improves the small signal gain and noise figure by about 4.8 dB and 1.6 dB, respectively. By employing a double-pass configuration, a higher gain can be obtained with an expense of a noise figure penalty. The gain improvement of 17.0 dB is obtained at 20 mW and -50 dBm of pump and input signal powers. This shows that the double-pass configuration is an important aspect to consider when designing an efficient EYDFA.

  8. Single Ion Quantum Lock-In Amplifier

    CERN Document Server

    Kotler, Shlomi; Glickman, Yinnon; Keselman, Anna; Ozeri, Roee

    2011-01-01

    We report on the implementation of a quantum analog to the classical lock-in amplifier. All the lock-in operations: modulation, detection and mixing, are performed via the application of non-commuting quantum operators on the electronic spin state of a single trapped Sr+ ion. We significantly increase its sensitivity to external fields while extending phase coherence by three orders of magnitude, to more than one second. With this technique we measure magnetic fields with sensitivity of 25 pT/sqrt(Hz) and light shifts with an uncertainty below 140 mHz after 1320 seconds of averaging. These sensitivities are limited by quantum projection noise and, to our knowledge, are more than two orders of magnitude better than with other single-spin probe technologies. In fact, our reported sensitivity is sufficient for the measurement of parity non-conservation, as well as the detection of the magnetic field of a single electronic-spin one micrometer from an ion-detector with nanometer resolution. As a first application ...

  9. Amplification uncertainty relation for probabilistic amplifiers

    Science.gov (United States)

    Namiki, Ryo

    2015-09-01

    Traditionally, quantum amplification limit refers to the property of inevitable noise addition on canonical variables when the field amplitude of an unknown state is linearly transformed through a quantum channel. Recent theoretical studies have determined amplification limits for cases of probabilistic quantum channels or general quantum operations by specifying a set of input states or a state ensemble. However, it remains open how much excess noise on canonical variables is unavoidable and whether there exists a fundamental trade-off relation between the canonical pair in a general amplification process. In this paper we present an uncertainty-product form of amplification limits for general quantum operations by assuming an input ensemble of Gaussian-distributed coherent states. It can be derived as a straightforward consequence of canonical uncertainty relations and retrieves basic properties of the traditional amplification limit. In addition, our amplification limit turns out to give a physical limitation on probabilistic reduction of an Einstein-Podolsky-Rosen uncertainty. In this regard, we find a condition that probabilistic amplifiers can be regarded as local filtering operations to distill entanglement. This condition establishes a clear benchmark to verify an advantage of non-Gaussian operations beyond Gaussian operations with a feasible input set of coherent states and standard homodyne measurements.

  10. Status Report on the Energy Amplifier

    CERN Document Server

    Rubbia, Carlo

    1994-01-01

    0ne year after its first presentation,the Energy Amplifier (EA) Project holds its promises for a environmentally acceptable form of energy extraction from nuclei, namely to eliminate or at least greatly reduce(i) the environmental impact of the long-lived highly radioactive waste;(ii) the possibility of diversions toward military applications;(iii) the risks of an accidental divergence related to the critical operation of the chain reaction and (iv) make a more efficient use of a fuel which is less radio-toxic to extract and more abundant on Earth than Uranium. In these respects the EA (or equivalent scenarios from Los Alamos and elsewhere) is comparable in performance to Thermonuclear Fusion. Bot h approches offer pratically unl;imited fuel resources: the energetic content of Lithium on the Earth's crust needed by Fusion is estimated to be seven times the one of Thorium and they are both adequate for millions of years of very intensived utilisation.However the EA can be built economically,in a variety of siz...

  11. Novel photoacid generators for chemically amplified resists

    Science.gov (United States)

    Yamato, Hitoshi; Asakura, Toshikage; Matsumoto, Akira; Ohwa, Masaki

    2002-07-01

    Recently we have developed new class of non-ionic oxime sulfonate PAG. The compounds generate various kinds of sulfonic acids, such as n-propane, n-octane, camphor and p-toluene sulfonic acid under Deep-UV exposure and are applicable for chemically amplified (CA) photoresists. The application-relevant properties of the compounds such as solubility in propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, ethyl 3-ethoxypropionate, and 2-heptanone, UV absorption, thermal stability with or without poly(4-hydroxystyrene) (PHS), storage stability in a neat form or in PGMEA solution with or without additives, sensitivity in a model resist formulation, dissolution inhibition efficiency during the development process and volatility were evaluated. The compounds exhibit good solubility in PGMEA, high sensitivity in positive tone CA resist formulations, with Deep-UV exposure, and no significant volatility. Especially it was found that the compounds are superior in terms of thermal stability and storage stability, i.e., high thermal stability up to 188 degree(s)C in a phenolic matrix, and no change during storage in PGMEA at 60 degree(s)C for 5 months.

  12. Gold Nanoparticle Labels Amplify Ellipsometric Signals

    Science.gov (United States)

    Venkatasubbarao, Srivatsa

    2008-01-01

    The ellipsometric method reported in the immediately preceding article was developed in conjunction with a method of using gold nanoparticles as labels on biomolecules that one seeks to detect. The purpose of the labeling is to exploit the optical properties of the gold nanoparticles in order to amplify the measurable ellipsometric effects and thereby to enable ultrasensitive detection of the labeled biomolecules without need to develop more-complex ellipsometric instrumentation. The colorimetric, polarization, light-scattering, and other optical properties of nanoparticles depend on their sizes and shapes. In the present method, these size-and-shape-dependent properties are used to magnify the polarization of scattered light and the diattenuation and retardance of signals derived from ellipsometry. The size-and-shape-dependent optical properties of the nanoparticles make it possible to interrogate the nanoparticles by use of light of various wavelengths, as appropriate, to optimally detect particles of a specific type at high sensitivity. Hence, by incorporating gold nanoparticles bound to biomolecules as primary or secondary labels, the performance of ellipsometry as a means of detecting the biomolecules can be improved. The use of gold nanoparticles as labels in ellipsometry has been found to afford sensitivity that equals or exceeds the sensitivity achieved by use of fluorescence-based methods. Potential applications for ellipsometric detection of gold nanoparticle-labeled biomolecules include monitoring molecules of interest in biological samples, in-vitro diagnostics, process monitoring, general environmental monitoring, and detection of biohazards.

  13. Fishing amplifies forage fish population collapses

    Science.gov (United States)

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  14. A highly linear power amplifier for WLAN

    Science.gov (United States)

    Jie, Jin; Jia, Shi; Baoli, Ai; Xuguang, Zhang

    2016-02-01

    A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus. Project supported by the National Natural Science Foundation of China (No. 61201244) and the Natural Science Fund of SUES (No. E1-0501-14-0168).

  15. An energy-efficient micropower neural recording amplifier.

    Science.gov (United States)

    Wattanapanitch, W; Fee, M; Sarpeshkar, R

    2007-06-01

    This paper describes an ultralow-power neural recording amplifier. The amplifier appears to be the lowest power and most energy-efficient neural recording amplifier reported to date. We describe low-noise design techniques that help the neural amplifier achieve input-referred noise that is near the theoretical limit of any amplifier using a differential pair as an input stage. Since neural amplifiers must include differential input pairs in practice to allow robust rejection of common-mode and power supply noise, our design appears to be near the optimum allowed by theory. The bandwidth of the amplifier can be adjusted for recording either neural spikes or local field potentials (LFPs). When configured for recording neural spikes, the amplifier yielded a midband gain of 40.8 dB and a -3-dB bandwidth from 45 Hz to 5.32 kHz; the amplifier's input-referred noise was measured to be 3.06 muVrms while consuming 7.56 muW of power from a 2.8-V supply corresponding to a noise efficiency factor (NEF) of 2.67 with the theoretical limit being 2.02. When configured for recording LFPs, the amplifier achieved a midband gain of 40.9 dB and a -3-dB bandwidth from 392 mHz to 295 Hz; the input-referred noise was 1.66 muVrms while consuming 2.08 muW from a 2.8-V supply corresponding to an NEF of 3.21. The amplifier was fabricated in AMI's 0.5-mum CMOS process and occupies 0.16 mm(2) of chip area. We obtained successful recordings of action potentials from the robust nucleus of the arcopallium (RA) of an anesthesized zebra finch brain with the amplifier. Our experimental measurements of the amplifier's performance including its noise were in good accord with theory and circuit simulations. PMID:23851668

  16. A modular positive feedback-based gene amplifier

    Directory of Open Access Journals (Sweden)

    Bhalerao Kaustubh D

    2010-02-01

    Full Text Available Abstract Background Positive feedback is a common mechanism used in the regulation of many gene circuits as it can amplify the response to inducers and also generate binary outputs and hysteresis. In the context of electrical circuit design, positive feedback is often considered in the design of amplifiers. Similar approaches, therefore, may be used for the design of amplifiers in synthetic gene circuits with applications, for example, in cell-based sensors. Results We developed a modular positive feedback circuit that can function as a genetic signal amplifier, heightening the sensitivity to inducer signals as well as increasing maximum expression levels without the need for an external cofactor. The design utilizes a constitutively active, autoinducer-independent variant of the quorum-sensing regulator LuxR. We experimentally tested the ability of the positive feedback module to separately amplify the output of a one-component tetracycline sensor and a two-component aspartate sensor. In each case, the positive feedback module amplified the response to the respective inducers, both with regards to the dynamic range and sensitivity. Conclusions The advantage of our design is that the actual feedback mechanism depends only on a single gene and does not require any other modulation. Furthermore, this circuit can amplify any transcriptional signal, not just one encoded within the circuit or tuned by an external inducer. As our design is modular, it can potentially be used as a component in the design of more complex synthetic gene circuits.

  17. Ambient temperature cadmium zinc telluride radiation detector and amplifier circuit

    International Nuclear Information System (INIS)

    A low noise, low power consumption, compact, ambient temperature signal amplifier for a Cadmium Zinc Telluride (CZT) radiation detector is disclosed. The amplifier can be used within a larger system (e.g., including a multi-channel analyzer) to allow isotopic analysis of radionuclides in the field. In one embodiment, the circuit stages of the low power, low noise amplifier are constructed using integrated circuit (IC) amplifiers , rather than discrete components, and include a very low noise, high gain, high bandwidth dual part preamplification stage, an amplification stage, and an filter stage. The low noise, low power consumption, compact, ambient temperature amplifier enables the CZT detector to achieve both the efficiency required to determine the presence of radionuclides and the resolution necessary to perform isotopic analysis to perform nuclear material identification. The present low noise, low power, compact, ambient temperature amplifier enables a CZT detector to achieve resolution of less than 3% full width at half maximum at 122 keV for a Cobalt-57 isotope source. By using IC circuits and using only a single 12 volt supply and ground, the novel amplifier provides significant power savings and is well suited for prolonged portable in-field use and does not require heavy, bulky power supply components. 9 figs

  18. Direct solar-pumped iodine laser amplifier

    Science.gov (United States)

    Han, Kwang S.; Hwang, In Heon; Kim, Khong Hon; Stock, Larry V.

    1988-01-01

    A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of rate equations was improved to increase the accuracy and the efficiency of the calculation. The improved algorithm was applied to explain the existing experimental data taken from a flashlamp pumped iodine laser for three kinds of lasants, i-C3F7I, n-C4F9I, and t-C4F9I. Various solid laser materials were evaluated for solar-pumping. The materials studied were Nd:YAG, Nd:YLF, and Cr:Nd:GSGG crystals. The slope efficiency of 0.17 percent was measured for the Nd:YLF near the threshold pump intensity which was 211 solar constants (29W/sq cm). The threshold pump intensity of the Nd:YAG was measured to be 236 solar constants (32W/sq cm) and the near-threshold slope efficiency was 0.12 percent. True CW laser operation of Cr:Nd:GSGG was possible only at pump intensities less than or equal to 1,500 solar constants (203 W/sq cm). This fact was attributed to the high thermal focusing effect of the Cr:Nd:GSGG rod.

  19. An Adaptive Amplifier System for Wireless Sensor Network Applications

    OpenAIRE

    Carlos Marqués; Eduardo Romero; Mónica Lovay; Gabriela Peretti

    2012-01-01

    This paper presents an adaptive amplifier that is part of a sensor node in a wireless sensor network. The system presents a target gain that has to be maintained without direct human intervention despite the presence of faults. In addition, its bandwidth must be as large as possible. The system is composed of a software-based built-in self-test scheme implemented in the node that checks all the available gains in the amplifiers, a reconfigurable amplifier, and a genetic algorithm (GA) for rec...

  20. Experimental demonstration of a W-band gyroklystron amplifier

    OpenAIRE

    Blank, M.; Danly, B.; Levush, B.; Latham, P; Pershing, D.

    1997-01-01

    The experimental demonstration of a four cavity W-band (93 GHz) gyroklystron amplifier is reported. The gyroklystron has produced 67 kW peak output power and 28% efficiency in the TE011 mode using a 55 kV, 4.3 A electron beam. The full width at half maximum instantaneous bandwidth is greater than 460 MHz, a significant increase over the bandwidth demonstrated in previous W-band gyroklystron amplifier experiments. The amplifier is unconditionally stable at this operating point. Experimental re...

  1. Experimental Demonstration of a W-Band Gyroklystron Amplifier

    Science.gov (United States)

    Blank, M.; Danly, B. G.; Levush, B.; Latham, P. E.; Pershing, D. E.

    1997-12-01

    The experimental demonstration of a four cavity W-band (93 GHz) gyroklystron amplifier is reported. The gyroklystron has produced 67 kW peak output power and 28% efficiency in the TE011 mode using a 55 kV, 4.3 A electron beam. The full width at half maximum instantaneous bandwidth is greater than 460 MHz, a significant increase over the bandwidth demonstrated in previous W-band gyroklystron amplifier experiments. The amplifier is unconditionally stable at this operating point. Experimental results are in good agreement with theoretical predictions.

  2. Introduction to RF power amplifier design and simulation

    CERN Document Server

    Eroglu, Abdullah

    2015-01-01

    Introduction to RF Power Amplifier Design and Simulation fills a gap in the existing literature by providing step-by-step guidance for the design of radio frequency (RF) power amplifiers, from analytical formulation to simulation, implementation, and measurement. Featuring numerous illustrations and examples of real-world engineering applications, this book:Gives an overview of intermodulation and elaborates on the difference between linear and nonlinear amplifiersDescribes the high-frequency model and transient characteristics of metal-oxide-semiconductor field-effect transistorsDetails activ

  3. Fast amplifier associated with the Saturne II detection systems

    International Nuclear Information System (INIS)

    This research thesis concerns the nuclear spectroscopy station which is beside the Saturne synchrotron in Saclay, and more particularly the design of the large bandwidth amplifier which aims at bringing the anode signal to a sufficient value to trigger an amplitude discriminator or a coincidence circuit. This amplifier must have a very short rise time in order not to introduce a hold, and its output base line must be as little sensitive as possible to the counting frequency, which implies a continuous link. The author describes in detail the rationale for the use of such an amplifier, and reports the calculated and measured assessment of its different characteristics

  4. MMIC DHBT Common-Base Amplifier for 172 GHz

    Science.gov (United States)

    Paidi, Vamsi; Griffith, Zack; Wei, Yun; Dahlstrom, Mttias; Urteaga, Miguel; Rodwell, Mark; Samoska, Lorene; Fung, King Man; Schlecht, Erich

    2006-01-01

    Figure 1 shows a single-stage monolithic microwave integrated circuit (MMIC) power amplifier in which the gain element is a double-heterojunction bipolar transistor (DHBT) connected in common-base configuration. This amplifier, which has been demonstrated to function well at a frequency of 172 GHz, is part of a continuing effort to develop compact, efficient amplifiers for scientific instrumentation, wide-band communication systems, and radar systems that will operate at frequencies up to and beyond 180 GHz. The transistor is fabricated from a layered structure formed by molecular beam epitaxy in the InP/InGaAs material system. A highly doped InGaAs base layer and a collector layer are fabricated from the layered structure in a triple mesa process. The transistor includes two separate emitter fingers, each having dimensions of 0.8 by 12 m. The common-base configuration was chosen for its high maximum stable gain in the frequency band of interest. The input-matching network is designed for high bandwidth. The output of the transistor is matched to a load line for maximum saturated output power under large-signal conditions, rather than being matched for maximum gain under small-signal conditions. In a test at a frequency of 172 GHz, the amplifier was found to generate an output power of 7.5 mW, with approximately 5 dB of large-signal gain (see Figure 2). Moreover, the amplifier exhibited a peak small-signal gain of 7 dB at a frequency of 176 GHz. This performance of this MMIC single-stage amplifier containing only a single transistor represents a significant advance in the state of the art, in that it rivals the 170-GHz performance of a prior MMIC three-stage, four-transistor amplifier. [The prior amplifier was reported in "MMIC HEMT Power Amplifier for 140 to 170 GHz" (NPO-30127), NASA Tech Briefs, Vol. 27, No. 11 (November 2003), page 49.] This amplifier is the first heterojunction- bipolar-transistor (HBT) amplifier built for medium power operation in this

  5. The Dynamics of Semiconductor Optical Amplifiers – Modeling and Applications

    DEFF Research Database (Denmark)

    Mørk, Jesper; Nielsen, Mads Lønstrup; Berg, Tommy Winther

    2003-01-01

    The importance of semiconductor optical amplifiers is discussed. A semiconductor optical amplifier (SOA) is a semiconductor laser with anti-reflection coated facets that amplifies an injected light signal by means of stimulated emission. SOAs have a number of unique properties that open up...... significant opportunities in the area of fast, all-optical signal processing. Integrated SOA-based devices are considered suitable for future all-optical systems because of their compact size, low optical and electrical power consumption, polarization independence and high speed....

  6. FDML swept source at 1060 nm using a tapered amplifier

    DEFF Research Database (Denmark)

    Marschall, Sebastian; Klein, Thomas; Wieser, Wolfgang;

    2010-01-01

    We present a novel frequency-swept light source working at 1060nm that utilizes a tapered amplifier as gain medium. These devices feature significantly higher saturation power than conventional semiconductor optical amplifiers and can thus improve the limited output power of swept sources in this...... wavelength range. We demonstrate that a tapered amplifier can be integrated into a fiber-based swept source and allows for high-speed FDML operation. The developed light source operates at a sweep rate of 116kHz with an effective average output power in excess of 30mW. With a total sweep range of 70 nm an...

  7. Recovery of solitons with nonlinear amplifying loop mirrors

    Science.gov (United States)

    Gabitov, Ildar; Holm, Darryl D.; Luce, Benjamin P.; Mattheus, Arnold

    1995-12-01

    We study the use of nonlinear amplifying loop mirrors to recover soliton pulses nonadiabatically deformed by losses. We approach this problem as a mapping problem of input pulse to output pulse, for segments of fiber followed by a combination of linear and nonlinear amplification. For a wide range of amplifier spacings, we find numerically that a single optimal input pulse of soliton shape exists for each amplifier spacing, which is well recovered at output. The recovered output pulses contain only \\similar 3% continuous radiation.

  8. Class-D audio amplifiers with negative feedback

    OpenAIRE

    Cox, Stephen M.; Candy, B. H.

    2006-01-01

    There are many different designs for audio amplifiers. Class-D, or switching, amplifiers generate their output signal in the form of a high-frequency square wave of variable duty cycle (ratio of on time to off time). The square-wave nature of the output allows a particularly efficient output stage, with minimal losses. The output is ultimately filtered to remove components of the spectrum above the audio range. Mathematical models are derived here for a variety of related class-D amplifier d...

  9. 120 nm Bandwidth Erbium-doped Fiber Amplifier

    Institute of Scientific and Technical Information of China (English)

    姜淳; 曾庆济; 肖石林

    2002-01-01

    A new dual band erbium-doped fiber amplifier configuration that provides 120 nm of optical bandwidth is simulated. This configuration employs a split-band architecture in which optical signals are splitted using a 1550/1610 nm port filter into two independent sub-bands which then pass in parallel through separate branches of the optical amplifier. Each branch may be optimized for the sub-band that traverses it. The independent sub-bands are combined and flattened before output, resulting in a 120 nm bandwidth gain-flattened optical amplifier.

  10. Efficient performance simulation of class D amplifier output stages

    DEFF Research Database (Denmark)

    Nyboe, Flemming; Risbo, Lars; Andreani, Pietro

    Straightforward simulation of amplifier distortion involves transient simulation of operation on a sine wave input signal, and a subsequent FFT of the output voltage. This approach is very slow on class D amplifiers, since the switching behavior forces simulation time steps that are many orders o...... magnitude smaller than the duration of one period of an audio sine wave. This work presents a method of simulating the amplifier transfer characteristic using a minimum amount of simulation time, and then deriving THD from the results....

  11. A hybrid copper/gold laser pumped dye amplifier

    Science.gov (United States)

    Ainsworth, M. D.; Piper, J. A.

    1989-01-01

    The design and operating characteristics of a high average power copper vapour laser pumped dye amplifier which is injected with the 627.8 nm output of a gold vapour laser are reported. In these experiments both the CVL pump and GVL injection signals are obtained from a modified CVL plasma tube. Amplifier gain and efficiency as functions of both the pump and injection power, for a number of dyes and dye mixtures, were investigated. Amplifier efficiencies of 25% are reported for CVL pump powers of 4 W and GVL injection powers of only 50 mW.

  12. Influence of mode competition on beam quality of fiber amplifier

    International Nuclear Information System (INIS)

    Theoretical and experimental studies of the influence of the mode competition on the output beam quality of fiber amplifiers are presented. Rate equations and modal decomposition method are used in the theoretical model. In the experiment, the output beam-quality factor of a fiber amplifier, which is based on a Yb-doped double-clad large mode area fiber as a function of the seed beam quality and the pump power of the amplifier, is measured. The experimental results are consistent with the theoretical analysis. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  13. Fiber optical parametric amplifiers in optical communication systems

    DEFF Research Database (Denmark)

    Marhic, Michel E.; Andrekson, Peter A.; Petropoulos, Periklis;

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time...... excess of 14,000 Tb/s x km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed....

  14. Design procedure for optimizing CMOS low noise operational amplifiers

    Institute of Scientific and Technical Information of China (English)

    Li Zhiyuan; Ye Yizheng; Ma Jianguo

    2009-01-01

    This paper presents and experimentally verifies an optimized design procedure for a CMOS low noise operational amplifier.The design procedure focuses on the noise performance,which is the key requirement for low noise operational amplifiers.Based on the noise level and other specifications such as bandwidth,signal swing,slew rate,and power consumption,the device sizes and the biasing conditions are derived.In order to verify the proposed design procedure,a three-stage operational amplifier has been designed.The device parameters obtained from the proposed design procedure closely agree with the simulated results obtained by using HSPICE.

  15. Hearing Aids and Personal Sound Amplifiers: Know the Difference

    Science.gov (United States)

    ... For Consumers Home For Consumers Consumer Updates Hearing Aids and Personal Sound Amplifiers: Know the Difference Share ... or use them as substitutes—for approved hearing aids. "Hearing aids and personal sound amplification products (PSAPS) ...

  16. Experiments of High Power 35GHz Gyro-Klystron Amplifiers

    Science.gov (United States)

    Choi, Jin; McCurdy, A.; Wood, F.; Kyser, R.; Danly, B.; Levush, B.; Calame, J.; Parker, R.

    1997-11-01

    Experiments on a two-cavity gyroklystron amplifier operating at 35GHz were successfully carried out. The amplifier produced a saturated radiation power of 210kW which corresponds to an efficiency of 37% and a gain of 23.6dB. The experimental results are in good agreement with predicted performance from non-linear gyroklystron codes, MAGYKL and MAGY. Experiments on a staggered tuned three-cavity gyroklystron amplifier is currently underway to demonstrate a high gain and wideband rf amplification. Simulations on the three-cavity gyroklystron circuit predict an instantaneous bandwidth of 0.9% and a gain of 35dB. Experimental results of the amplifiers will be presented.

  17. Development of High Power Microwave and Millimeter Wave Gyroklystron Amplifiers

    Science.gov (United States)

    Han, W. K.; Baik, S. W.; Lee, S. H.; Choi, J. J.; Park, D. M.; Oh, J. H.; Yang, J. G.; Hwang, S. M.; Temkin, R.

    1999-11-01

    A design study of a 28GHz gyroklystron amplifier for application of ECR plasma heating at Hanbit has been completed. Numerical simulation codes predict that a stable amplifier radiation of 200kW is produced with a 54dB saturated gain and an electronic efficiency of 35 percent from a 70kV and 8.2A high power electron beam. Major experimental equipments including a high power modulator, a 2 Tesla superconducting magnet, and a double-anode magnetro-injection-gun have been procured and are expected to set up in laboratory by this fall. Fabrication of tube components is currently underway. Cold-tests of the rf components are presented. In addition, experiments on a 10GHz gyroklystron amplifier which is a scale-down version of 28GHz gyroklystron amplifier are planned in the near future.

  18. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  19. Apparatus and methods for a human de-amplifier system

    International Nuclear Information System (INIS)

    A human de-amplifier system is described for interfacing a human operator and a physical object through a physical plant, wherein the physical object has dimensions in the range of 1 micrometer to 1 mm. The human de-amplifier system uses an inner-feedback loop to increase the equivalent damping of the operating system to stabilize the system when it contacts with the environment and reduces the impact of the environment variation by utilizing a high feedback gain, determined by a root locus sketch. Because the stability of the human de-amplifier system of the present invention is greatly enhanced over that of the prior art, the de-amplifier system is able to manipulate the physical object having dimensions in the range of 1 micrometer to 1 mm with high stability and accuracy. The system also has a monitoring device to monitor the motion of the physical object under manipulation

  20. Gain Variation with Raman Amplifier Parameters and Its Restoration

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We demonstrate that gain profile of a distributed Raman amplifier is sensitive to its parameter variation, such as loss/gain coefficients change or partial pump failure. Gain flatness can be restored by adjusting power of pump lasers.

  1. Real burst traffic amplification in optically gain clamped amplifier

    OpenAIRE

    Ennser, Karin; Taccheo, Stefano; Careglio, Davide; Solé Pareta, Josep; Aracil Rico, Javier

    2008-01-01

    Optical burst amplification in a gain-stabilized amplifier is theoretically investigated using real burst traffic data. The results show that excellent performance are obtained for WDM transmission with negligible interplay due to burst arrival statistics.

  2. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    implications of driving the non-linear transducer of the DEAP. 2-level modulated high voltage amplifiers driving the capacitive load of the DEAP transducer are addressed in chapter 4. An amplifier with fourth order output filter and full-state self-oscillating hysteresis based control loop is proposed...... on a silicone film. As a consequence a capacitive transducer emerges, which can be shaped into the loudspeaker membrane itself, rolled up into a transducer driving a membrane or being part of an active suspension system for the membrane. In order to document the full potential of the DEAP transducer, suitable....... Due to the similarities between the electrostatic loudspeaker and the DEAP transducer, the state-of-the-art has a special focus on amplifiers for electrostatic loudspeakers. Amplifiers for other type of capacitive transducers like piezoelectric ones are also considered. Finally the current state...

  3. High current density nanofilament cathodes for microwave amplifiers

    NARCIS (Netherlands)

    Schnell, J-P.; Minoux, E.; Gangloff, L.; Vincent, P.; Legagneux, P.; Dieumegard, D.; David, J.-F.; Peauger, F.; Hudanski, L.; Teo, K.B.K.; Lacerda, R.; Chhowalla, M.; Hasko, D.G.; Ahmed, H.; Amaratunga, G.A.J.; Milne, W.I.; Vila, L.; Dauginet-De Pra, L.; Demoustier-Champagne, S.; Ferain, E.; Legras, R.; Piraux, L.; Gröening, O.; Raedt, H. De; Michielsen, K.

    2004-01-01

    We study high current density nanofilament cathodes for microwave amplifiers. Two different types of aligned nanofilament array have been studied: first, metallic nanowires grown by electrodeposition into nanoporous templates at very low temperature (T

  4. Quantum Dot Semiconductor Optical Amplifiers - Physics and Applications

    DEFF Research Database (Denmark)

    Berg, Tommy Winther

    2004-01-01

    This thesis describes the physics and applications of quantum dot semiconductor optical amplifiers based on numerical simulations. These devices possess a number of unique properties compared with other types of semiconductor amplifiers, which should allow enhanced performance of semiconductor...... and QW devices and to experiments on quantum dot amplifiers. These comparisons outline the qualitative differences between the different types of amplifiers. In all cases focus is put on the physical processes responsible the differences....... devices in communication systems in the future. The basic properties of quantum dot devices are investigated, especially regarding the potential of realizing amplification and signal processing without introducing pattern dependence. Also the gain recovery of a single short pulse is modeled...

  5. Linear and nonlinear analysis of high-power rf amplifiers

    International Nuclear Information System (INIS)

    After a survey of the state variable analysis method the final amplifier for the CBA is analyzed taking into account the real beam waveshape. An empirical method for checking the stability of a non-linear system is also considered

  6. Compression of chirp pulses from a femtosecond fiber based amplifier

    Science.gov (United States)

    Ito, Rumi; Takiuchi, Ken-ichi; Tei, Kazuyoku; Yamaguchi, Shigeru; Enokidani, Jyun; Sumida, Shin

    2015-03-01

    We demonstrate a single mode fiber based master oscillator power amplifier (MOPA) with a single polarization and a fully monolithic design. We have built a passive mode-locked polarization maintaining Yb doped fiber as the master oscillator contains a semiconductor saturable absorber mirror and a chirped fiber Bragg grating for the dispersion management. The net intracavity dispersion was managed to be slightly anomalous. The oscillator generates the 150 fs (sech2) pulses at the center wavelength of 1065 nm, and the repetition rate of 42 MHz. The oscillator output was amplified to 1.4 W from 80 mW in the single stage fiber amplifier which results in pulse shape distortion. The pulse shaping with a band pass filter and a compressor was applied to the amplified pulses. The shaping pulses have the pulse width of 90 fs and the pulse energy of 16 nJ.

  7. Fast terahertz imaging using a quantum cascade amplifier

    International Nuclear Information System (INIS)

    A terahertz (THz) imaging scheme based on the effect of self-mixing in a 2.9 THz quantum cascade (QC) amplifier has been demonstrated. By coupling an antireflective-coated silicon lens to the facet of a QC laser, with no external optical feedback, the laser mirror losses are enhanced to fully suppress lasing action, creating a THz QC amplifier. The addition of reflection from an external target to the amplifier creates enough optical feedback to initiate lasing action and the resulting emission enhances photon-assisted transport, which in turn reduces the voltage across the device. At the peak gain point, the maximum photon density coupled back leads to a prominent self-mixing effect in the QC amplifier, leading to a high sensitivity, with a signal to noise ratio up to 55 dB, along with a fast data acquisition speed of 20 000 points per second

  8. Compensation of flicker noise in weak-signal amplifiers

    OpenAIRE

    A. S. Makarenko; Tertychny, G. N.

    2007-01-01

    The paper considers the block diagram of a weak-signal low-frequency amplifier, describes its principle of operation, and presents results of the theoretical and experimental investigation in compensation of flicker noise in the new device.

  9. Development of SPND amplifier using hybrid micro circuit

    International Nuclear Information System (INIS)

    Self-Powered Neutron Detector (SPND) is an in-core neutron detector of compact size, rugged construction and long life with a very simple associated signal processing electronics due to absence of high voltage bias. Because of the reasons mentioned above, the SPNDs are being used in large numbers for all types of nuclear reactors. The paper describes the development of SPND amplifier using low power components and hybrid microcircuit with advanced features like on-line detector health monitoring and buffered output among others. This development will be reduced the mechanical size and power requirement of SPND amplifier considerably as compared with earlier developed SPND amplifier using discrete components. The present amplifier design is compact and accommodates two SPND channels in the existing 1 width module. (author)

  10. Distributed Mode Filtering Rod Fiber Amplifier With Improved Mode Stability

    DEFF Research Database (Denmark)

    Laurila, Marko; Alkeskjold, Thomas Tanggaard; Broeng, Jes;

    2012-01-01

    We report 216W of average output power from a photonic crystal rod fiber amplifier. We demonstrate 44% power improvement before onset of the mode instability by operating the rod fiber in a leaky guiding regime.......We report 216W of average output power from a photonic crystal rod fiber amplifier. We demonstrate 44% power improvement before onset of the mode instability by operating the rod fiber in a leaky guiding regime....

  11. Dynamics of Continuously Pumped Solid-State Regenerative Amplifiers

    OpenAIRE

    Grishin, Mikhail; Michailovas, Andrejus

    2010-01-01

    Continuously pumped regenerative amplifiers are subject to energy instability at high pulse repetition rates due to period doubling bifurcation. Theoretical concepts representing a generalized picture of operation features have been in-detail worked out in order to differentiate and understand instability effects. Experimental data for Nd:YVO4 regenerative amplifier have been presented; and possible techniques for performance optimization have been analyzed. An increase in the seed pulse ener...

  12. Gas cooled disk amplifier approach to solid state average power

    International Nuclear Information System (INIS)

    Disk amplifiers have been used on almost all solid state laser systems of high energy, and, in principle, one simply has to cool the device to operate it at average power. To achieve the desired waste heat removal, gas is flowed across the disk surface. The authors show the basic gas flow geometry. They computationally and experimentally characterize the flow and its optical implications over regimes which far exceed the envisioned operating requirements of a working amplifier

  13. Efficient development of highly linear MMIC power amplifiers

    OpenAIRE

    Bignamini, M.; Favre, G.; Meazza, A.; Pagani, M.; Palomba, F.; Sivverini, G.

    2001-01-01

    Highly linear power amplifiers are key components of high capacity radio transmitters. This paper describes the complete procedure we established to develop a family of new MMIC power amplifiers aimed at achieving state-of-the-art performance as needed for a new M-QAM microwave radio. A cost effective approach dedicated to volume production has been addressed. The most important experimental characteristics for each of the developed MMIC PAs are also reported in order to demostrate the effect...

  14. Ultrafast optical signal processing using semiconductor quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2002-01-01

    The linear and nonlinear properties of quantum dot amplifiers are discussed on the basis of an extensive theoretical model. These devices show great potential for linear amplification as well as ultrafast signal processing.......The linear and nonlinear properties of quantum dot amplifiers are discussed on the basis of an extensive theoretical model. These devices show great potential for linear amplification as well as ultrafast signal processing....

  15. Amplifying ribbon extensometer for measuring film and fabric strain

    Science.gov (United States)

    Alley, V. L., Jr.; Mchatton, A. D.

    1975-01-01

    Variations of a low-cost amplifying linear threshold extensometer are presented in detail for high or low strain applications. Derivations of scale relationships and extraction forces are included with experimental correlations and analyses given on performance, attachment problems, gain selection, gage and base material compatibility, and zero setting techniques. Flight applications of unamplified gages on parawing deployment tests are noted. The amplified gages perform accurately in laboratory tests and further experience is needed on performance under dynamic environments.

  16. On the effect of time delays in negative feedback amplifiers

    OpenAIRE

    Alves, L. N.; Aguiar, R. L.

    2005-01-01

    Time delays are intrinsic to all existing devices and circuits. For the majority of applications, time delays are so small that their effects can be disregarded. However, when considering feedback amplifiers, depending on open-loop poles and loop gain, the effect of a small time delay inside the feedback path may turn to be of considerable importance. This paper analyzes the frequency response effects associated with time delays in feedback amplifiers, exploiting these effects to achieve band...

  17. DESIGN OF SEQUENTIALLY FED BALANCED AMPLIFYING ANTENNA FOR CIRCULAR POLARIZATION

    OpenAIRE

    S. K. Behera; D. R. Poddar; Mishra, R K

    2010-01-01

    This paper presents a sequentially fed balanced amplifying antenna that exhibits circularly polarized radiation. The inherent benefits of good isolation between input and output ports as well as improved matching capabilities of balanced amplifiers provide overall system gain of 8 dBi at frequency 2.36GHz. The planar arrangement of the patch antenna elements are considered to form an array. The phase of the feeding in the array increases progressively from 00 to 2700.Each element in the array...

  18. Analysis and Investigation of Noise Figure of Fiber Raman Amplifier

    OpenAIRE

    Ramanpreet Kaur; Kirandeep Kaur

    2012-01-01

    Raman amplifiers are widely used for high capacity long haul communication systems. One of the main reason for which it can be used is its improved noise figure. In this paper noise figure of Raman amplifiers is studied and analysed for different pumping schemes. The main sources of noise and their effects on the noise figure are discussed and the methods to reduce the noise figure are proposed.

  19. Characterization of a multimode coplanar waveguide parametric amplifier

    International Nuclear Information System (INIS)

    We characterize a Josephson parametric amplifier based on a flux-tunable quarter-wavelength resonator. The fundamental resonance frequency is ∼1 GHz, but we use higher modes of the resonator for our measurements. An on-chip tuning line allows for magnetic flux pumping of the amplifier. We investigate and compare degenerate parametric amplification, involving a single mode, and nondegenerate parametric amplification, using a pair of modes. We show that we reach quantum-limited noise performance in both cases

  20. HFSS Simulation of Vacuum Tube RF Power Amplifiers

    CERN Document Server

    Zviagintsev, Vladimir

    2005-01-01

    Development and upgrade of rf power amplifiers require comprehensive calculations to predict and optimize various parameters of the system before hardware modifications are applied. ANSOFT HFSS code provides a powerful tool for 3D EM simulation of the amplifier output resonator comprising a vacuum tube as a passive element. Two examples of this kind of simulation applied for upgrade of the TRIUMF Cyclotron rf system are presented in this paper.

  1. A high-power compact regenerative amplifier FEL

    International Nuclear Information System (INIS)

    The Regenerative Amplifier FEL (RAFEL) is a new FEL approach aimed at achieving the highest optical power from a compact rf-linac FEL. The key idea is to feed back a small fraction (5 in single pass) wiggler to enable the FEL to reach saturation in a few passes. This paper summarizes the design of a high-power compact regenerative amplifier FEL and describes the first experimental demonstration of the RAFEL concept

  2. An amplifier for VUV photomultiplier operating in cryogenic environment

    Science.gov (United States)

    Arneodo, F.; Benabderrahmane, M. L.; Dahal, S.; Di Giovanni, A.; d`Inzeo, M.; Franchi, G.; Pazos Clemens, L.

    2016-07-01

    We present the characterisation of an amplifier potentially interesting for noble liquid detectors. The design has been conceived considering the requirements of low power consumption (less than 30 mW), low noise, amplification factor of 10 at 100 MHz and use of commercial components. The amplifier has been integrated onto an electronic board with a voltage divider to operate an Hamamatsu R11410 photomultiplier tube (used in XENON1T, Aprile et al. (2014) [1] dark matter experiment).

  3. Behavioral modeling and linearization of RF power amplifiers

    CERN Document Server

    Wood, John

    2014-01-01

    Wireless voice and data communications have made great improvements, with connectivity now virtually ubiquitous. Users are demanding essentially perfect transmission and reception of voice and data. The infrastructure that supports this wide connectivity and nearly error-free delivery of information is complex, costly, and continually being improved.This resource describes the mathematical methods and practical implementations of linearization techniques for RF power amplifiers for mobile communications. This includes a review of RF power amplifier design for high efficiency operation. Readers

  4. Resonantly phase-matched Josephson junction traveling wave parametric amplifier

    OpenAIRE

    O'Brien, Kevin; Macklin, Chris; Siddiqi, Irfan; Zhang, Xiang

    2014-01-01

    We develop a technique to overcome phase-mismatch in Josephson-junction traveling wave parametric amplifiers in order to achieve high gain over a broad bandwidth. Using "resonant phase matching," we design a compact superconducting device consisting of a transmission line with subwavelength resonant inclusions that simultaneously achieves a gain of 20 dB, an instantaneous bandwidth of 3 GHz, and a saturation power of -98 dBm. Such an amplifier is well-suited to cryogenic broadband microwave m...

  5. Design of low noise transimpedance amplifier for intravascular ultrasound

    KAUST Repository

    Reda, Dina

    2009-11-01

    In this paper, we study transimpedance amplifiers for capacitive sensing applications with a focus on Intravascular Ultra Sound (IVUS). We employ RF noise cancellation technique on capacitive feedback based transimpedance amplifiers. This technique eliminates the input-referred noise of TIAs completely and enhances the dynamic range of front-end electronics. Simulation results verify the proposed technique used in two different TIA topologies employing shunt-shunt feedback. ©2009 IEEE.

  6. On the dual symmetry between absorbing and amplifying random media

    Indian Academy of Sciences (India)

    S Anantha Ramakrishna

    2004-06-01

    We re-examine the dual symmetry between absorbing and amplifying random media. By analysing the physically allowed choice of the sign of the square root to determine the complex wave vector in a medium, we draw a broad set of conclusions that enables us to resolve the apparent paradox of the dual symmetry and also to anticipate the large local electromagnetic field enhancements in amplifying random media.

  7. Yb:YAG single crystal fiber image amplifier

    Science.gov (United States)

    Wan, Peng; Liu, Jian; Yang, Lih-Mei; Bai, Shuang

    2014-02-01

    In the paper, a Yb:YAG single crystal fiber is used for the first time to amplify week image signal. It was longitudinally pumped by a fiber-coupled laser diode with a maximum power of 150W at 940 nm. The image amplifier provided low noise and high gain amplification. A spatially uniform amplification gain of up to 10.2 dB at wavelength of 1030 nm was obtained.

  8. ANALYSIS OF INTERNALLY GENERATED NOISE OF BIOELECTRIC AMPLIFIERS

    Institute of Scientific and Technical Information of China (English)

    MashhourMustafaBaniAmer

    2003-01-01

    This papenr deals with internally generated noise of bioelectric amplifiers that are usually used for processing of bioelectric events.The main purpose of this paper is to present a procedure for analysis of the effects of internal noise generated by the active circuits and to evaluate the output noise of the author's new designed bioelectric amplifier that caused by internal effects to the amplifier circuit itself in order to compare it with the noise generated by conventional amplifiers.The obtained analysis results of internally generated noise showed that the total output noise of bioelectric active circuits does not increase when some of their resitors have a larger value.This behavior is caused by the different transfer functions for the signal and the respective noise sources associated with these resistors.Moreover,the new designed bioelectric amplifier haws an output noise less than that for conventional amplifiers.The obtained analysis results were also experimentally verified and the final conclusions were drawn.

  9. Status of solid-state power amplifiers development in BARC

    International Nuclear Information System (INIS)

    Various solid-state power amplifiers have been developed to meet the requirements of accelerator needs for BARC and its collaboration projects. These are mainly 352 and 325 MHz RF power amplifiers. The 352 MHz, RF power amplifier have been developed to feed the buncher cavity of the Low Energy High Intensity Proton Accelerator (LEHIPA). Whereas 325 MHz 3 kW and 7 kW solid- state power amplifiers have been designed under the IIFC-Fermilab collaboration. The same technologies will also be used for 200 MeV superconducting accelerator of ADS program. The paper present the technology details of the power amplifier modules, power combiners, dividers and sensors etc. The developed SSPAs are of 3 kW, 325 MHz and 10 kW 352 MHz. Both the power amplifiers have been tested on a 50 ohm load. The 3 kW SSPA has the drain efficiency of 65.3%. The four modules have the power output of 850 W each. This SSPA has the figure of merit of SSPAs (number of modules per kW) is 1.2. The 10 kW SSPA is mainly required to feed the buncher cavity of the LEHIPA. It is combination of 16 power modules of 800 W each at 352 MHz. (author)

  10. Frequency-Offset Cartesian Feedback Based on Polyphase Difference Amplifiers.

    Science.gov (United States)

    Zanchi, Marta G; Pauly, John M; Scott, Greig C

    2010-05-01

    A modified Cartesian feedback method called "frequency-offset Cartesian feedback" and based on polyphase difference amplifiers is described that significantly reduces the problems associated with quadrature errors and DC-offsets in classic Cartesian feedback power amplifier control systems.In this method, the reference input and feedback signals are down-converted and compared at a low intermediate frequency (IF) instead of at DC. The polyphase difference amplifiers create a complex control bandwidth centered at this low IF, which is typically offset from DC by 200-1500 kHz. Consequently, the loop gain peak does not overlap DC where voltage offsets, drift, and local oscillator leakage create errors. Moreover, quadrature mismatch errors are significantly attenuated in the control bandwidth. Since the polyphase amplifiers selectively amplify the complex signals characterized by a +90° phase relationship representing positive frequency signals, the control system operates somewhat like single sideband (SSB) modulation. However, the approach still allows the same modulation bandwidth control as classic Cartesian feedback.In this paper, the behavior of the polyphase difference amplifier is described through both the results of simulations, based on a theoretical analysis of their architecture, and experiments. We then describe our first printed circuit board prototype of a frequency-offset Cartesian feedback transmitter and its performance in open and closed loop configuration. This approach should be especially useful in magnetic resonance imaging transmit array systems. PMID:20814450

  11. Power Amplifier Design for E-band Wireless System Communications

    DEFF Research Database (Denmark)

    Hadziabdic, Dzenan; Krozer, Viktor; Johansen, Tom Keinicke

    2008-01-01

    E-band wireless communications will become important as the microwave backhaul for high-speed data transmission. One of the most critical components is the front-end power amplifier in this system. The paper analyzes different technologies with potential in the E-band frequency range and present a...... power amplifier design satisfying the E-band system specifications. The designed power amplifier achieves a maximum output power of ges 20 dBm with a state-of-the-art power-added efficiency of 15%. The power is realized using InP DHBT technology. To the best of our knowledge it is the highest output...... power and efficiency reported for an InP HBT power amplifier in this frequency range. The predicted power-added efficiency is higher than that of power amplifiers based on SiGe HBT and GaAs pHEMT technologies. The design shows the capabilities of InP DHBT for power amplifier applications as an...

  12. Quantum noise in Josephson-junction parametric amplifiers

    International Nuclear Information System (INIS)

    Crossover between thermal and quantum noise in the externally-pumped Josephson-junction parametric amplifiers is theoretically followed. Two different approaches are used for the analysis: Josephson junction is replaced with its RSJ model with the equilibrium source of fluctuations; microscopic theory of the tunnel junctions is used, which takes into account not only thermal and quantum but also shot noise. Because of inconvenience of the noise temperature T /SUB N/ for the amplifier sensitivity characterization in the quantum limit, the authors express their results in terms of the figure theta /SUB N/ which is essentially the amplifier output noise energy, reduced to its input (in the classical limit, theta /SUB N/ =k /SUB B/ T /SUB N/). For the nondegenerate amplifier, the minimum value of theta /SUB N/ equals hω/2 and is due to quantum noise (zeropoint oscillations) in the idle-frequency resonator of the amplifier. For the degenerate amplifier, sensitive to only one quadrature component of the input signal, theta /SUB N/ can be made much less than the above ''quantum limit'' even at operation temperatures much higher than hω/k /SUB B/, if the Josephson junction characteristic frequency ω /SUB c/ is high enough, hω /SUB c/ k /SUB B/ T. An analysis of the experimental situation shows that the values theta /SUB N/ < can be achieved using two-dimensional arrays of a large number (N approx. = 100) single-tunnel-junction interferometers with low inductances, inductively coupled to a microwave cavity

  13. Improving Students' Understanding of Lock-In Amplifiers

    Science.gov (United States)

    DeVore, Seth; Gauthier, Alexandre; Levy, Jeremy; Chandralekha, Singh

    2014-03-01

    A lock-in amplifier is a versatile instrument frequently used in physics research. However, many students struggle with the basic operating principles of a lock-in amplifier which can lead to a variety of difficulties. To improve students' understanding, we have been developing and evaluating a research-based tutorial which makes use of a computer simulation of a lock-in amplifier. The tutorial is based on a field-tested approach in which students realize their difficulties after predicting the outcome of simulated experiments involving a lock-in amplifier and check their predictions using the simulated lock-in amplifier. Then, the tutorial guides and helps students develop a coherent understanding of the basics of a lock-in amplifier. The tutorial development involved interviews with physics faculty members and graduate students and iteration of many versions of the tutorial with professors and graduate students. The student difficulties and the development and assessment of the research-based tutorial are discussed. We thank National Science Foundation for award NSF-1124131.

  14. Improving Students' Understanding of Lock-in Amplifiers

    CERN Document Server

    DeVore, Seth; Levy, Jeremy; Singh, Chandralekha

    2016-01-01

    A lock-in amplifier is a versatile instrument frequently used in physics research. However, many students struggle with the basic operating principles of a lock-in amplifier which can lead to a variety of difficulties. To improve students' understanding, we have been developing and evaluating a research-based tutorial which makes use of a computer simulation of a lock-in amplifier. The tutorial is based on a field-tested approach in which students realize their difficulties after predicting the outcome of simulated experiments involving a lock-in amplifier and check their predictions using the simulated lock-in amplifier. Then, the tutorial guides and helps students develop a coherent understanding of the basics of a lock-in amplifier. The tutorial development involved interviews with physics faculty members and graduate students and iteration of many versions of the tutorial with professors and graduate students. The student difficulties and the development and assessment of the research-based tutorial are d...

  15. Design and development of 1 KW solid state RF amplifier

    International Nuclear Information System (INIS)

    Since low power tube based RF amplifiers are complicated, occupy a large space and are bulky, the efforts are on to develop indigenously 1 KW solid state technology based RF Power amplifier. A power level of 1KW is chosen for the initial design because RF power Mosfets upto 250 watt are easily available and by clubbing 3-4 stages the power level of 1 KW can be made. Presently design and testing of 100-watt stage is in progress. The first 2 stages are designed to give 5 Watt RF power using bipolar transistors and are operated in CE, Class A to provide low noise level at the output of the system. The 3rd stage will be MOSFET based MRF 174, which is ideally suited for class A operation and is designed for 100 Watt RF power. The last stage will be MOSFET based ARF446 power MOSFET in TO-247 plastic package. This amplifier will be used in the classical push- pull configuration. This paper describes the design aspects as well as the test results of 100 watt amplifier on 50 Ohm dummy load along with the specifications, design criteria, circuit used, operating parameters of 1 KW Solid State RF power amplifier to be used as driver for 91.2 MHz, 1.5 MW stage for ICRH experiments on SST-1 tokamak .

  16. Spectroscopic amplifier for pin diode; Amplificador espectroscopico para diodo Pin

    Energy Technology Data Exchange (ETDEWEB)

    Alonso M, M. S.; Hernandez D, V. M.; Vega C, H. R., E-mail: bebe.luna_s@hotmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2014-10-15

    The photodiode remains the basic choice for the photo-detection and is widely used in optical communications, medical diagnostics and field of corpuscular radiation. In detecting radiation it has been used for monitoring radon and its progeny and inexpensive spectrometric systems. The development of a spectroscopic amplifier for Pin diode is presented which has the following characteristics: canceler Pole-Zero (P/Z) with a time constant of 8 μs; constant gain of 57, suitable for the acquisition system; 4th integrator Gaussian order to waveform change of exponential input to semi-Gaussian output and finally a stage of baseline restorer which prevents Dc signal contribution to the next stage. The operational amplifier used is the TLE2074 of BiFET technology of Texas Instruments with 10 MHz bandwidth, 25 V/μs of slew rate and a noise floor of 17 nv/(Hz)1/2. The integrated circuit has 4 operational amplifiers and in is contained the total of spectroscopic amplifier that is the goal of electronic design. The results show like the exponential input signal is converted to semi-Gaussian, modifying only the amplitude according to the specifications in the design. The total system is formed by the detector, which is the Pin diode, a sensitive preamplifier to the load, the spectroscopic amplifier that is what is presented and finally a pulse height analyzer (Mca) which is where the spectrum is shown. (Author)

  17. Design of A Microwave Amplifier for Wireless Application

    Directory of Open Access Journals (Sweden)

    M. H. Ullah

    2012-01-01

    Full Text Available Problem statement: Low-Noise Amplifiers (LNA are very indispensable components in the design of numerous types of communication receivers employed in microwave technology. This paper is presents the design and development of low bias(Vce = 8v, Ic =10 mA single stage low noise microwave amplifier operating in 1.5GHZ frequency range, Gain 13dB ± 0.5dB, input/output return loss Approach: The principal design target is to obtain a minimum noise figure while concomitantly achieving a maximum gain by presenting the optimum noise impedance (Zopt which is characteristically implemented by adding a matching circuit between the source and the input of the amplifier. Results: The proposed low-noise amplifier for microwave wireless application is designed, simulated and optimized using Serenade Harmonica (by Ansoft Corporation and Advance Design System (ADS software by Agilent. Conclusion: In this paper a low-noise amplifier operated at 1.5 GHz. is designed because of the significant roles played in the field of microwave communication technology, which includes the application in the output stage of a transmitter where the signals needs to be strengthen before transmission.

  18. Using MEMS Capacitive Switches in Tunable RF Amplifiers

    Directory of Open Access Journals (Sweden)

    Danson John

    2006-01-01

    Full Text Available A MEMS capacitive switch suitable for use in tunable RF amplifiers is described. A MEMS switch is designed, fabricated, and characterized with physical and RF measurements for inclusion in simulations. Using the MEMS switch models, a dual-band low-noise amplifier (LNA operating at GHz and GHz, and a tunable power amplifier (PA at GHz are simulated in m CMOS. MEMS switches allow the LNA to operate with 11 dB of isolation between the two bands while maintaining dB of gain and sub- dB noise figure. MEMS switches are used to implement a variable matching network that allows the PA to realize up to 37% PAE improvement at low input powers.

  19. Cooling of solid-state amplifiers with supercritical hydrogen

    International Nuclear Information System (INIS)

    This study addresses the thermal management of microwave solid-state amplifiers which are potential candidates for power systems at 425 and 850 MHz. Researchers at Los Alamos National Laboratory have investigated the cooling of extremely high density packaging of RF amplifier modules with a heat removal requirement of about 200 W/cm2. The technique uses water as a coolant which flows into the microchannels directly imbedded in the chips. The microchannel concept was first proposed by Tuckerman and Pease in 1981 and is capable of removing up to 1 kW/cm2 from silicon integrated circuits using water as the coolant. Previous studies, have demonstrated that on-board supercritical hydrogen can be used to cool solid-state amplifiers. Even though the heat transfer coefficient is lower for hydrogen compared to water, this deficiency is recouped by having a colder heat sink which is hydrogen at cryogenic temperatures

  20. Frequency-shifted feedback amplifier for broadband laser cooling

    Science.gov (United States)

    Lim, Michael; van Kooy, Alexander; Yanakas, Michael

    2014-03-01

    We have developed a compact, all-solid state laser amplifier for generating asymmetric sidebands with controlled number and spacing of optical frequencies. The gain element is a tapered semiconductor amplifier, used in conjunction with an acousto-optic modulator that generates red-detuned feedback frequencies. This results in asymmetric sidebands that are all lower in optical frequency than the narrowband seed laser frequency. The output laser spectrum has a well-defined edge (the input laser frequency) and multiple sidebands whose number, frequency spacing, and power are fully controlled by the seed laser characteristics and a single radio frequency input. The number of sidebands can be varied in a controlled way, and the output optical power is variable up to the Watt level of the amplifier chip. The system will be used for broadband laser cooling.

  1. Two-qubit parametric amplifier: large amplification of weak signals

    CERN Document Server

    Savel'ev, S; Rakhmanov, A L; Omelyanchouk, A N; Washington, Z; Nori, Franco

    2012-01-01

    Using numerical simulations, we show that two coupled qubits can amplify a weak signal about hundredfold. This can be achieved if the two qubits are biased simultaneously by this weak signal and a strong pump signal, both of which having frequencies close to the inter-level transitions in the system. The weak signal strongly affects the spectrum generated by the strong pumping drive by producing and controlling mixed harmonics with amplitudes of the order of the main harmonic of the strong drive. We show that the amplification is robust with respect to noise, with an intensity of the order of the weak signal. When deviating from the optimal regime (corresponding to strong qubit coupling and a weak-signal frequency equal to the inter-level transition frequency) the proposed amplifier becomes less efficient, but it can still considerably enhance a weak signal (by several tens). We therefore propose to use coupled qubits as a combined parametric amplifier and frequency shifter.

  2. Theoretical Analysis of Rayleigh Backscattering Noise in Fiber Raman Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, a new theoretical model for Rayleigh backscattering (RB) analysis of fiber Raman amplifiers is proposed. The model includes all the interactions among the pumps, signals, and all orders of RB. The results show that the higher order RB has a negligible influence on the performance of the amplifier. The co-propagating and counterpropagating RB power of the signal grow quadratically with the net-gain of the amplifier. The signal to double Rayleigh backscattering noise ratio (OSNRDRB ) of backward-pumped FRAs is better than that of the forward-pumped ones at high net-gain level (> 13 dB), while at low net-gain level the OSNRDrb of the forward-pumped FRAs is slightly better than that of the backward-pumped ones.

  3. Josephson traveling-wave parametric amplifier for superconducting qubit readout

    Science.gov (United States)

    Macklin, Chris; Slichter, D. H.; Yaakobi, O.; Friedland, L.; Bolkhovsky, V.; Braje, D. A.; Fitch, G.; Oliver, W. D.; Siddiqi, I.

    2014-03-01

    Superconducting parametric amplifiers (paramps) have successfully demonstrated near quantum limited sensitivity, enabling single-shot qubit readout, feedback, and state tracking. However, these amplifiers are commonly limited to narrow bandwidth and modest dynamic range, and most require microwave circulators to separate input and output modes. These limitations stem from the use of a resonant non-linearity to achieve mixing between a signal and pump mode. Our traveling-wave parametric amplifier (TWPA) is based on a superconducting nonlinear Josephson junction transmission line, thereby inherently sidestepping the limitations associated with a cavity structure. We present theoretical predictions and experimental results, including improved gain and noise performance. We discuss transmon qubit readout in the circuit QED architecture using a TWPA. We also comment on promising architectures for chip-level integration and multiplexing. Work supported by IARPA.

  4. Spectrally tailored supercontinuum generation from single-mode-fiber amplifiers

    International Nuclear Information System (INIS)

    Spectral filtering of an all-normal-dispersion Yb-doped fiber laser was demonstrated effective for broadband supercontinuum generation in the picosecond time region. The picosecond pump pulses were tailored in spectrum with 1 nm band-pass filter installed between two single-mode fiber amplifiers. By tuning the spectral filter around 1028 nm, four-wave mixing was initiated in a photonic crystal fiber spliced with single-mode fiber, as manifested by the simultaneous generation of Stokes wave at 1076 nm and anti-Stokes wave at 984 nm. Four-wave mixing took place in cascade with the influence of stimulated Raman scattering and eventually extended the output spectrum more than 900 nm of 10 dB bandwidth. This technique allows smooth octave supercontinuum generation by using simple single-mode fiber amplifiers rather than complicated multistage large-mode-area fiber amplifiers.

  5. Embedded control system for high power RF amplifiers

    International Nuclear Information System (INIS)

    RF power devices are usually very sensitive to overheat and reflected RF power; hence a protective interlock system is required to be embedded with high power solid state RF amplifiers. The solid state RF amplifiers have salient features of graceful degradation and very low mean time to repair (MTTR). In order to exploit these features in favour of lowest system downtime, a real-time control system is embedded with high power RF amplifiers. The control system is developed with the features of monitoring, measurement and network publishing of various parameters, historical data logging, alarm generation, displaying data to the operator and tripping the system in case of any interlock failure. This paper discusses the design philosophy, features, functions and implementation details of the embedded control system. (author)

  6. Short-pulse propagation in fiber optical parametric amplifiers

    DEFF Research Database (Denmark)

    Cristofori, Valentina

    Fiber optical parametric amplifiers (FOPAs) are attractive because they can provide large gain over a broad range of central wavelengths, depending only on the availability of a suitable pump laser. In addition, FOPAs are suitable for the realization of all-optical signal processing functionalities...... and can operate with a potentially low noise figure with respect to erbium-doped fiber amplifiers and Raman amplifiers, when working in phase-sensitive configurations. A characterization of the signal distortion mechanisms introduced by FOPAs is relevant for investigating the applicability of FOPAs...... pulses fiber laser source is implemented to obtain an all-fiber system. The advantages of all fiber-systems are related to their reliability, long-term stability and compactness. Fiber optical parametric chirped pulse amplification is promising for the amplification of such signals thanks to the inherent...

  7. Spectrally tailored supercontinuum generation from single-mode-fiber amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Qiang; Guo, Zhengru; Zhang, Qingshan [Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China); Liu, Yang; Li, Wenxue [State Key Laboratory of Precision Spectroscopy, East China Normal University, 3663 Zhongshan North Road, Shanghai 200062 (China); Zeng, Heping, E-mail: hpzeng@phy.ecnu.edu.cn [Shanghai Key Laboratory of Modern Optical System, Engineering Research Center of Optical Instrument and System (Ministry of Education), School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Shanghai 200093 (China); State Key Laboratory of Precision Spectroscopy, East China Normal University, 3663 Zhongshan North Road, Shanghai 200062 (China)

    2014-05-19

    Spectral filtering of an all-normal-dispersion Yb-doped fiber laser was demonstrated effective for broadband supercontinuum generation in the picosecond time region. The picosecond pump pulses were tailored in spectrum with 1 nm band-pass filter installed between two single-mode fiber amplifiers. By tuning the spectral filter around 1028 nm, four-wave mixing was initiated in a photonic crystal fiber spliced with single-mode fiber, as manifested by the simultaneous generation of Stokes wave at 1076 nm and anti-Stokes wave at 984 nm. Four-wave mixing took place in cascade with the influence of stimulated Raman scattering and eventually extended the output spectrum more than 900 nm of 10 dB bandwidth. This technique allows smooth octave supercontinuum generation by using simple single-mode fiber amplifiers rather than complicated multistage large-mode-area fiber amplifiers.

  8. Efficiency Optimization in Class-D Audio Amplifiers

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Knott, Arnold; Jørgensen, Ivan Harald Holger;

    2015-01-01

    This paper presents a new power efficiency optimization routine for designing Class-D audio amplifiers. The proposed optimization procedure finds design parameters for the power stage and the output filter, and the optimum switching frequency such that the weighted power losses are minimized under...... the given constraints. The optimization routine is applied to minimize the power losses in a 130 W class-D audio amplifier based on consumer behavior investigations, where the amplifier operates at idle and low power levels most of the time. Experimental results demonstrate that the optimization...... method can lead to around 30 % of efficiency improvement at 1.3 W output power without significant effects on both audio performance and the efficiency at high power levels....

  9. 400W Yb:YAG Innoslab fs-Amplifier.

    Science.gov (United States)

    Russbueldt, P; Mans, T; Rotarius, G; Weitenberg, J; Hoffmann, H D; Poprawe, R

    2009-07-20

    The Innoslab design, already established for neodymium doped laser crystals, was applied to ytterbium doped laser materials. Recent progresses in brightness of high power diode lasers facilitate efficient pumping of quasi-three-level laser materials. Innoslab amplifiers are compared to competing thin-disk and fiber fs-amplifiers. A compact diode-pumped Yb:YAG Innoslab fs-oscillator-amplifier system, scalable to the kilowatt range, was realized. Numerical simulations result in conditions for high efficiency and beam quality. Nearly transform and diffraction limited 680 fs pulses at 400 W average output power and 76 MHz repetition rate without using CPA technology have been achieved at room temperature so far. PMID:19654625

  10. Design of Low Noise Microwave Amplifiers Using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Sadık Ülker

    2012-07-01

    Full Text Available This short paper presents a work on the design of low noise microwave amplifiers using particle swarm optimization (PSO technique. Particle Swarm Optimization is used as a method that is applied to a single stage amplifier circuit to meet two criteria: desired gain and desired low noise. The aim is to get the best optimized design using the predefined constraints for gain and low noise values. The code is written to apply the algorithm to meet the desired goals and the obtained results are verified using different simulators. The results obtained show that PSO can be applied very efficiently for this kind of design problems with multiple constraints.

  11. Investigation of accelerator's characteristics used for an energy amplifier

    International Nuclear Information System (INIS)

    The sub-critical reactor of the energy amplifier is a kind of swimming pool reactors, operates by fast neutron and uses ThO2 + 0.1U233 as fuel. The long cylindrical fuel bars are arranged in constant steps according to a hexagonal configuration. The two fuel assemblies are with the 12.43 mm and 11.38 mm fuel bar steps. The cell group parameters and effective neutron multiplication coefficient of the energy amplifier including two neutron energy groups are defined by the WIMS-D homogenization code. Their calculating results are presented. (NHA)

  12. Solid-state microwave high-power amplifiers

    CERN Document Server

    Sechi, Franco

    2009-01-01

    This practical resource offers expert guidance on the most critical aspects of microwave power amplifier design. This comprehensive book provides descriptions of all the major active devices, discusses large signal characterization, explains all the key circuit design procedures. Moreover you gain keen insight on the link between design parameters and technological implementation, helping you achieve optimal solutions with the most efficient utilization of available technologies. The book covers a broad range of essential topics, from requirements for high-power amplifiers, device models, phas

  13. Tapered amplifier laser with frequency-shifted feedback

    CERN Document Server

    Bayerle, A; Vlaar, P; Pasquiou, B; Schreck, F

    2016-01-01

    We present a frequency-shifted feedback (FSF) laser based on a tapered amplifier. The laser operates as a coherent broadband source with up to 370GHz spectral width and 2.3us coherence time. If the FSF laser is seeded by a continuous-wave laser a frequency comb spanning the output spectrum appears in addition to the broadband emission. The laser has an output power of 280mW and a center wavelength of 780nm. The ease and flexibility of use of tapered amplifiers makes our FSF laser attractive for a wide range of applications, especially in metrology.

  14. Resonant Phase Matching of Josephson Junction Traveling Wave Parametric Amplifiers

    Science.gov (United States)

    O'Brien, Kevin; Macklin, Chris; Siddiqi, Irfan; Zhang, Xiang

    2014-10-01

    We propose a technique to overcome phase mismatch in Josephson-junction traveling wave parametric amplifiers in order to achieve high gain over a broad bandwidth. Using "resonant phase matching," we design a compact superconducting device consisting of a transmission line with subwavelength resonant inclusions that simultaneously achieves a gain of 20 dB, an instantaneous bandwidth of 3 GHz, and a saturation power of -98 dBm. Such an amplifier is well suited to cryogenic broadband microwave measurements such as the multiplexed readout of quantum coherent circuits based on superconducting, semiconducting, or nanomechanical elements, as well as traditional astronomical detectors.

  15. Rare-Earth Doped Photonic Crystal Fibre Lasers and Amplifiers

    DEFF Research Database (Denmark)

    Hougaard, Kristian G.

    2005-01-01

    In this thesis, a theoretical and numerical study of the use of rare-earthdoped photonic crystal fibres as optical amplifiers and lasers, has been performed. Photonic crystal fibres or microstructured optical fibres is a new kind of optical fibre in which the cladding region typically consist of a....... The thesis also presents the basic properties of optical amplification, and describes the numerical model developed to model the behaviour of lasers and amplifiers based on photonic crystal fibres. The developed numerical tools are then used to investigate specific applications of photonic crystal...

  16. Design of Low Noise Microwave Amplifiers Using Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Sadık Ulker

    2012-08-01

    Full Text Available This short paper presents a work on the design of low noise microwave amplifiers using particle swarmoptimization (PSO technique. Particle Swarm Optimization is used as a method that is applied to a singlestage amplifier circuit to meet two criteria: desired gain and desired low noise. The aim is to get the bestoptimized design using the predefined constraints for gain and low noise values. The code is written toapply the algorithm to meet the desired goals and the obtained results are verified using differentsimulators. The results obtained show that PSO can be applied very efficiently for this kind of designproblems with multiple constraints.

  17. Dispersion-Engineered Traveling Wave Kinetic Inductance Parametric Amplifier

    Science.gov (United States)

    Zmuidzinas, Jonas (Inventor); Day, Peter K. (Inventor)

    2014-01-01

    A traveling wave kinetic inductance parametric amplifier comprises a superconducting transmission line and a dispersion control element. The transmission line can include periodic variations of its dimension along its length. The superconducting material can include a high normal state resistivity material. In some instances the high normal state resistivity material includes nitrogen and a metal selected from the group consisting of titanium, niobium and vanadium. The traveling wave kinetic inductance parametric amplifier is expected to exhibit a noise temperature below 100 mK/GHz.

  18. Processing of Communication Signal Using Operational Transconductance Amplifier

    CERN Document Server

    Roy, A; Mondal, S; Ray, B N

    2010-01-01

    This paper proposes a signal processing methodology of communication system and realized that circuits using operational transconductance amplifier (OTA). Two important classes of communication circuit, delta modulator and compander have been designed using that procedure. In the first implementation coded pulse modulation system is demonstrated which employ sampling, quantizing and coding to convert analog waveforms to digital signals while the second gives data compression and expansion in digital communication system. The proposed compander circuit is realized with operational transconductance amplifier and diode. Required power supply to operate the circuit is 3.5V. Performance of the circuits realized with OTAs has been demonstrated through SPICE simulation.

  19. Microwave photonic interference mitigation filter based on semiconductor optical amplifier

    Science.gov (United States)

    Xu, Enming; Zhang, Xinliang; Zhou, Lina; Zhang, Yu; Yu, Yuan; Wang, Fei; Huang, Dexiu

    2009-11-01

    A microwave photonic interference mitigation filter is proposed and experimentally demonstrated. The structure is based on a recirculating delay line loop comprising a semiconductor optical amplifier (SOA) and a tunable narrowband optical filter. Converted signal used as negative tap is generated through wavelength conversion employing cross-gain modulation of amplified spontaneous emission spectrum of the SOA. The converted signal circulating in the RDL loop realizes a high quality factor (Q) response after photo-detection. A bandpass response with negative coefficients combined with a broadband allpass response achieves a notch response with flat passband.

  20. Low-noise FET amplifier for dc SQUID

    International Nuclear Information System (INIS)

    We report on the design, characterization, and operation of a low-noise FET-input differential amplifier, which is used as second stage for a dc SQUID in the electronic instrumentation of the gravitational wave detector of the Rome group at CERN. The 3-dB bandwidth of the amplifier is from 10 kHz to 1.5 MHz. At the SQUID modulation frequency of 70 kHz the voltage noise is 0.5 nV/(Hz)1/2, the current noise is 35 fA/(Hz)1/2

  1. Genome profiling of ERBB2-amplified breast cancers

    International Nuclear Information System (INIS)

    Around 20% of breast cancers (BC) show ERBB2 gene amplification and overexpression of the ERBB2 tyrosine kinase receptor. They are associated with a poor prognosis but can benefit from targeted therapy. A better knowledge of these BCs, genomically and biologically heterogeneous, may help understand their behavior and design new therapeutic strategies. We defined the high resolution genome and gene expression profiles of 54 ERBB2-amplified BCs using 244K oligonucleotide array-comparative genomic hybridization and whole-genome DNA microarrays. Expression of ERBB2, phosphorylated ERBB2, EGFR, IGF1R and FOXA1 proteins was assessed by immunohistochemistry to evaluate the functional ERBB2 status and identify co-expressions. First, we identified the ERBB2-C17orf37-GRB7 genomic segment as the minimal common 17q12-q21 amplicon, and CRKRS and IKZF3 as the most frequent centromeric and telomeric amplicon borders, respectively. Second, GISTIC analysis identified 17 other genome regions affected by copy number aberration (CNA) (amplifications, gains, losses). The expression of 37 genes of these regions was deregulated. Third, two types of heterogeneity were observed in ERBB2-amplified BCs. The genomic profiles of estrogen receptor-postive (ER+) and negative (ER-) ERBB2-amplified BCs were different. The WNT/β-catenin signaling pathway was involved in ER- ERBB2-amplified BCs, and PVT1 and TRPS1 were candidate oncogenes associated with ER+ ERBB2-amplified BCs. The size of the ERBB2 amplicon was different in inflammatory (IBC) and non-inflammatory BCs. ERBB2-amplified IBCs were characterized by the downregulated and upregulated mRNA expression of ten and two genes in proportion to CNA, respectively. IHC results showed (i) a linear relationship between ERBB2 gene amplification and its gene and protein expressions with a good correlation between ERBB2 expression and phosphorylation status; (ii) a potential signaling cross-talk between EGFR or IGF1R and ERBB2, which could influence

  2. Traveling-Wave Tube Amplifier for THz Frequencies

    DEFF Research Database (Denmark)

    Kotiranta, Mikko; Krozer, Viktor; Zhurbenko, Vitaliy

    tubes and gas lasers, but the ones available are too expensive or large for many applications. This work is related to the European project OPTHER (Optically driven terahertz amplifiers) which aims to realise a compact, powerful and efficient vacuum tube amplifier for the frequency range of 0.3 – 2......The lack of a compact and powerful terahertz source has been hindering the application of terahertz radiation in many fields. Frequency multipliers can be used in conjunction with an electronic solid-state source to obtain power levels up to around 1 mW. A higher power may be generated with vacuum...

  3. A Method To ModifyCorrect The Performance Of Amplifiers

    Directory of Open Access Journals (Sweden)

    Rohith Krishnan R

    2015-01-01

    Full Text Available Abstract The actual response of the amplifier may vary with the replacement of some aged or damaged components and this method is to compensate that problem. Here we use op-amp Fixator as the design tool. The tool helps us to isolate the selected circuit component from rest of the circuit adjust its operating point to correct the performance deviations and to modify the circuit without changing other parts of the circuit. A method to modifycorrect the performance of amplifiers by properly redesign the circuit is presented in this paper.

  4. In-amplifier mid-infrared supercontinuum generation.

    Science.gov (United States)

    Gauthier, Jean-Christophe; Fortin, Vincent; Duval, Simon; Vallée, Réal; Bernier, Martin

    2015-11-15

    Mid-infrared supercontinuum (SC) generation from 2.6 to 4.1 μm is demonstrated in a single-mode erbium-doped fluoride glass fiber amplifier pumped at 976 nm and seeded by an optical parametric generation (OPG) source emitting 400 ps pulses at 2.75 μm. Up to 82% of the SC power is generated beyond 3 μm. This novel and simple in-amplifier SC generation approach is promising for the development of compact and efficient sources operating in the mid-infrared, especially in the 3-5 μm band. PMID:26565846

  5. DC SQUID amplifier for NMR experiments on small samples

    International Nuclear Information System (INIS)

    Low noise preamplifiers are required for the detection of the magnetic resonance of small size samples or at low magnetic fields. According to calculations based on the en, in model. SQUID based amplifiers are more suitable to NMR experiments on small samples than semiconductor amplifiers. We propose an amplification method by frequency transposition using a DC SQUID. Such a system can be run over a broad range of frequency as the noise impedance of the stages subsequent to the SQUID is continually optimised. The measurements are in good agreement with our theoretical model, based on a simplified voltage to flux SQUID characteristic. (orig.)

  6. Current-Driven Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Buhl, Niels Christian; Andersen, Michael A. E.

    2012-01-01

    The conversion of electrical energy into sound waves by electromechanical transducers is proportional to the current through the coil of the transducer. However virtually all audio power amplifiers provide a controlled voltage through the interface to the transducer. This paper is presenting a...... switch-mode audio power amplifier not only providing controlled current but also being supplied by current. This results in an output filter size reduction by a factor of 6. The implemented prototype shows decent audio performance with THD + N below 0.1 %....

  7. Resonant phase matching of Josephson junction traveling wave parametric amplifiers.

    Science.gov (United States)

    O'Brien, Kevin; Macklin, Chris; Siddiqi, Irfan; Zhang, Xiang

    2014-10-10

    We propose a technique to overcome phase mismatch in Josephson-junction traveling wave parametric amplifiers in order to achieve high gain over a broad bandwidth. Using "resonant phase matching," we design a compact superconducting device consisting of a transmission line with subwavelength resonant inclusions that simultaneously achieves a gain of 20 dB, an instantaneous bandwidth of 3 GHz, and a saturation power of -98 dBm. Such an amplifier is well suited to cryogenic broadband microwave measurements such as the multiplexed readout of quantum coherent circuits based on superconducting, semiconducting, or nanomechanical elements, as well as traditional astronomical detectors. PMID:25375734

  8. High-power phase locking of a fiber amplifier array

    Science.gov (United States)

    Shay, T. M.; Baker, J. T.; Sanchez, A. D.; Robin, C. A.; Vergien, C. L.; Zeringue, C.; Gallant, D.; Lu, Chunte A.; Pulford, Benjamin; Bronder, T. J.; Lucero, Arthur

    2009-02-01

    We report high power phase locked fiber amplifier array using the Self-Synchronous Locking of Optical Coherence by Single-detector Electronic-frequency Tagging technique. We report the first experimental results for a five element amplifier array with a total locked power of more than 725-W. We will report on experimental measurements of the phase fluctuations versus time when the control loop is closed. The rms phase error was measured to be λ/60. Recent results will be reported. To the best of the authors' knowledge this is the highest fiber laser power to be coherently combined.

  9. An autozeroing amplifier using PFET hot-electron injection

    OpenAIRE

    Hasler, Paul; Minch, Bradley A.; Diorio, Chris; Mead, Carver

    1996-01-01

    We have developed an amplifier which removes its “off-set” as a natural part of its operation by modifying the charge on a floating gate. The charge on the floating gate is adapted by a combination of electron tunneling and hot-electron injection, resulting in a nonlinear high-pass filter with a cutoff frequency less than 1 Hz. We show experimental data from this autozeroing amplifier for various input waveforms, and an analytical model which fits the output waveforms. This autozeroing amplif...

  10. PHEMT Distributed Power Amplifier Adopting Broadband Impedance Transformer

    DEFF Research Database (Denmark)

    Narendra, K.; Limiti, E.; Paoloni, C.; Zhurbenko, Vitaliy

    2013-01-01

    A non-uniform drain line distributed power amplifier (DPA) employing a broadband impedance transformer is presented. The DPA is based on GaAs PHEMT technology. The impedance transformer employs asymmetric coupled lines and transforms a low output impedance of the amplifier to a standard 50 Ω...... transmission line. The output power of approximately 600 mW, with an associated gain of 9 dB and PAE greater than 30 percent, is demonstrated in the frequency range from 10 to 1800 MHz....

  11. Spatial and spectral imaging of LMA photonic crystal fiber amplifiers

    DEFF Research Database (Denmark)

    Laurila, Marko; Lægsgaard, Jesper; Alkeskjold, Thomas Tanggaard; Broeng, Jes

    2011-01-01

    We demonstrate modal characterization using spatial and spectral resolved (S2) imaging, on an Ytterbium-doped large-mode-area photonic crystal fiber (PCF) amplifier and compare results with conventional cut-off methods. We apply numerical simulations and step-index fiber experiments to calibrate...... our mathematical and experimental routines of our S2 imaging system. We systematically analyze higher order mode (HOM) content of a polarizing 40μm core double-clad PCF amplifier with various launching and coiling configurations. We demonstrate a HOM suppression of more than -24dB with variance of 2...

  12. Improving student understanding of lock-in amplifiers

    Science.gov (United States)

    DeVore, Seth; Gauthier, Alexandre; Levy, Jeremy; Singh, Chandralekha

    2016-01-01

    The lock-in amplifier is a versatile instrument frequently used in physics research. We find that students tend to struggle with its basic operating principles, leading to a variety of difficulties. To improve their understanding, we have developed a research-based tutorial that makes use of a computer simulated lock-in amplifier. The tutorial allows students to realize their conceptual difficulties by comparing their predictions with the outcome of the simulations, hopefully leading them to a better understanding of the process of lock-in amplification.

  13. Theory of the singly quasidegenerate Josephson junction parametric amplifier

    DEFF Research Database (Denmark)

    Sørensen, O.H.; Dueholm, B.; Mygind, Jesper;

    1980-01-01

    as incident thermal radiation is included in the discussion. It is shown that the noise temperature is virtually independent of noise injected from external sources and that minimum noise temperature is automatically achieved if the amplifier is tuned to maximize the gain-bandwidth product. The analytical...... that the performance of the amplifier characterized by properties such as gain-bandwidth product, noise temperature, and saturation depends strongly on the embedding microwave circuit. In particular any uncompensated series reactance may deteriorate the overall performance. Internal shot and Johnson noise as well...

  14. Thin-rod Yb:YAG regenerative laser amplifier

    Science.gov (United States)

    Maruko, A.; Nishio, M.; Matsubara, S.; Tanaka, M.; Takama, M.; Yoshida, T.; Kyomoto, K.; Okunishi, H.; Kato, K.; Shimabayashi, K.; Morioka, M.; Inayoshi, S.; Yamagata, S.; Kawato, S.

    2014-09-01

    High-average-power, high-repetition-rates picosecond-pulsed regenerative ytterbium-doped yttrium aluminum garnet (Yb:YAG) laser amplifiers were developed. The architecture used in the amplifiers, which are named as thin-rod, has a unique cooling scheme like slab lasers and also has a unique pumping scheme like photonic crystal fiber lasers, is suitable for high-average power Ytterbium lasers. This architecture also has high gain characteristics which is appropriate for the regenerative spectral and pulse shaping on high-repetition-rate, ultrashort-pulse amplifications.

  15. Spectral hole-burning and carrier-heating dynamics in quantum-dot amplifiers: Comparison with bulk amplifiers

    DEFF Research Database (Denmark)

    Borri, P.; Langbein, W.; Hvam, Jørn Märcher;

    2001-01-01

    The ultrafast gain dynamics in an electrically pumped InAs/InGaAs/GaAs quantum-dot amplifier are measured at room temperature with femtosecond resolution, and compared with results on an InGaAsP bulk amplifier. The role of spectral hole burning and carrier heating in the recovery of the gain...... compression is investigated. Reduced carrier heating for both gain and refractive index dynamics of the quantum-dot device is found, which is a promising prerequisite for high-speed applications....

  16. An Adaptive Amplifier System for Wireless Sensor Network Applications

    Directory of Open Access Journals (Sweden)

    Mónica Lovay

    2012-01-01

    Full Text Available This paper presents an adaptive amplifier that is part of a sensor node in a wireless sensor network. The system presents a target gain that has to be maintained without direct human intervention despite the presence of faults. In addition, its bandwidth must be as large as possible. The system is composed of a software-based built-in self-test scheme implemented in the node that checks all the available gains in the amplifiers, a reconfigurable amplifier, and a genetic algorithm (GA for reconfiguring the node resources that runs on a host computer. We adopt a PSoC device from Cypress for the node implementation. The performance evaluation of the scheme presented is made by adopting four different types of fault models in the amplifier gains. The fault simulation results show that GA finds the target gain with low error, maintains the bandwidth above the minimum tolerable bandwidth, and presents a runtime lower than exhaustive search method.

  17. Fiber amplifiers under thermal loads leading to transverse mode instability

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas Tanggaard;

    2014-01-01

    Transverse mode instability (TMI) in rare-earth doped fiber amplifiers operating above an average power threshold is caused by intermodal stimulated thermal Rayleigh scattering due to quantum defect heating. We investigate thermally induced longitudinal waveguide perturbations causing power...... operation stability at higher average powers....

  18. A European Project on Vacuum Tube Amplifiers for THz Amplification

    DEFF Research Database (Denmark)

    Paoloni, Claudio; Di Carlo, Aldo; Brunetti, Francesca;

    2012-01-01

    The OPTHER (Optically Driven THz amplifier) project supported by the European Commission within the Seventh Framework Program (FP7) represents the first joint European attempt to realize vacuum electron devices in THz range. The target of the project was to design and realize the first 1 THz vacuum...

  19. RF radiation measurement on the indigenously developed solid state amplifier

    International Nuclear Information System (INIS)

    A Solid State Radio Frequency (RF) Power Amplifier module for 300 W has been developed indigenously around 350 MHz centre frequency. A shielding enclosure for the amplifier has been designed to confine the non- ionizing - radiated and conducted emissions inside the enclosure. This design has been simulated in CST microwave studio and E fields and H fields were monitored around the enclosed amplifier. These simulated results for radiated and conducted fields have been presented here. Then the enclosure has been assembled with the amplifier. For this enclosed assembly, RF radiated and conducted field emissions were monitored outside the enclosure. In this paper, measurement methodology for the radiated and conducted field has been described. These measurements have been done according to established standards for the operating frequency range. Measurements have been carried out using an omenidirectional, frequency selective electromagnetic field measuring instrument. Measured field levels for this assembly have been compared with the ICNIRP defined safety limits for personal and occupational safety hazards. This paper describes in detail, all the measurements and their analysis. (author)

  20. The auditory organ: active amplifier and highly sensitive measuring system

    International Nuclear Information System (INIS)

    The present paper provides a brief review on topical issues of auditory physiology. Recent data on transduction mechanism and adaptation in hair cells as well as on the possible role of outer hair cells in amplifying basilar membrane motion are presented. Strategies of present physiological research in dealing with sensorineural deafness are discussed. (orig.)

  1. Multilevel inverter based class D audio amplifier for capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    The reduced semiconductor voltage stress makes the multilevel inverters especially interesting, when driving capacitive transducers for audio applications. A ± 300 V flying capacitor class D audio amplifier driving a 100 nF load in the midrange region of 0.1-3.5 kHz with Total Harmonic Distortion...

  2. Entanglement-based linear-optical qubit amplifier

    Czech Academy of Sciences Publication Activity Database

    Meyer-Scott, E.; Bula, M.; Bartkiewicz, K.; Černoch, Antonín; Soubusta, Jan; Jennewein, T.; Lemr, Karel

    2013-01-01

    Roč. 87, č. 1 (2013), "012327-1"-"012327-7". ISSN 1050-2947 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : quantum physics * photonics qubits * qubit amplifier Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.991, year: 2013

  3. Optimizing bandwidth and dynamic range of lumped Josephson parametric amplifiers

    Science.gov (United States)

    Eddins, A.; Vijay, R.; Macklin, C.; Minev, Z.; Siddiqi, I.

    2013-03-01

    Superconducting parametric amplifiers have revolutionized the field of quantum measurement by providing high gain, ultra-low noise amplification. They have been used successfully for high-fidelity qubit state measurements, probing nano-mechanical resonators, quantum feedback, and for microwave quantum optics experiments. Though several designs exist, a simple and robust architecture is the Lumped Josephson Parametric Amplifier (LJPA). This device consists of a capacitively shunted SQUID directly coupled to a transmission line to form a low quality factor (Q) nonlinear resonator. We discuss amplifiers which can be tuned over the full 4-8 GHz band with 20-25 dB of gain and 10 - 50 MHz of signal bandwidth. However, similar to other parametric amplifiers employing a resonant circuit, the LJPA suffers from low dynamic range and has a -1 dB gain compression point of order -130 dBm. We explore new designs comprised of an array of SQUIDs to improve the dynamic range. We will present the results of numerical simulations and preliminary experiments. We will also briefly discuss improvements obtained from different biasing methods and packaging. This research was supported by the Army Research Office under a QCT grant.

  4. Optimum design of Nd-doped fiber optical amplifiers

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Bjarklev, Anders Overgaard; Lumholt, Ole;

    1992-01-01

    The waveguide parameters for a Nd-doped fluoride (Nd:ZBLANP) fiber amplifier have been optimized for small-signal and booster operation using an accurate numerical model. The optimum cutoff wavelength is shown to be 800 nm and the numerical aperture should be made as large as possible. Around 80...

  5. Asymmetric gain-saturated spectrum in fiber optical parametric amplifiers

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Rottwitt, Karsten; Galili, Michael;

    2012-01-01

    We demonstrate experimentally and numerically an unexpected spectral asymmetry in the saturated-gain spectrum of single-pump fiber optical parametric amplifiers. The interaction between higher-order four-wave mixing products and dispersive waves radiated as an effect of third-order dispersion...

  6. Amplified fragment length polymorphism and virulence polymorphism in Puccinia hordei

    Science.gov (United States)

    Puccinia hordei is the causal agent of barley leaf rust. To study the genetic diversity in P. hordei, 45 isolates with diverse virulence patterns and geographical origins were analyzed using amplified fragment length polymorphism markers. Two pathotypes of Puccinia graminis f. sp. tritici and one is...

  7. The spectacular human nose: an amplifier of individual quality?

    Directory of Open Access Journals (Sweden)

    Åse Kristine Rognmo Mikalsen

    2014-04-01

    Full Text Available Amplifiers are signals that improve the perception of underlying differences in quality. They are cost free and advantageous to high quality individuals, but disadvantageous to low quality individuals, as poor quality is easier perceived because of the amplifier. For an amplifier to evolve, the average fitness benefit to the high quality individuals should be higher than the average cost for the low quality individuals. The human nose is, compared to the nose of most other primates, extraordinary large, fragile and easily broken—especially in male–male interactions. May it have evolved as an amplifier among high quality individuals, allowing easy assessment of individual quality and influencing the perception of attractiveness? We tested the latter by manipulating the position of the nose tip or, as a control, the mouth in facial pictures and had the pictures rated for attractiveness. Our results show that facial attractiveness failed to be influenced by mouth manipulations. Yet, facial attractiveness increased when the nose tip was artificially centered according to other facial features. Conversely, attractiveness decreased when the nose tip was displaced away from its central position. Our results suggest that our evaluation of attractiveness is clearly sensitive to the centering of the nose tip, possibly because it affects our perception of the face’s symmetry and/or averageness. However, whether such centering is related to individual quality remains unclear.

  8. Quantum dot amplifiers with high output power and low noise

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper

    2003-01-01

    Quantum dot semiconductor optical amplifiers have been theoretically investigated and are predicted to achieve high saturated output power, large gain, and low noise figure. We discuss the device dynamics and, in particular, show that the presence of highly inverted barrier states does not limit...

  9. Characterization of a high-power tapered semiconductor amplifier system

    CERN Document Server

    Voigt, D; Spreeuw, R J C; Van Linden van den Heuvell, H B

    2001-01-01

    We have characterized a semiconductor amplifier laser system which provides up to 200mW output after a single-mode optical fiber at 780nm wavelength. The system is based on a tapered semiconductor gain element, which amplifies the output of a narrow-linewidth diode laser. Gain and saturation are discussed as a function of operating temperature and injection current. The spectral properties of the amplifier are investigated with a grating spectrometer. Amplified spontaneous emission (ASE) causes a spectral background with a width of 4nm FWHM. The ASE background was suppressed to below our detection limit by a proper choice of operating current and temperature, and by sending the light through a single-mode optical fiber. The final ASE spectral density was less than 0.1nW/MHz, i.e. less than 0.2 % of the optical power. Related to an optical transition linewidth of $\\Gamma/2\\pi=6$ MHz for rubidium, this gives a background suppression of better than -82dB. An indication of the beam quality is provided by the fibe...

  10. State-dependent linear-optical qubit amplifier

    Czech Academy of Sciences Publication Activity Database

    Bartkiewicz, K.; Černoch, Antonín; Lemr, K.

    2013-01-01

    Roč. 88, č. 6 (2013), "062304-1"-"062304-7". ISSN 1050-2947 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : linear-optical qubit amplifier * quantum cloning * quantum cryptography Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.991, year: 2013

  11. Development and energization of IOT based RF amplifier

    International Nuclear Information System (INIS)

    A 704 MHz IOT based CW RF amplifier has been developed in VECC. It can also be used with proper tuning to power cavity modules operating at 650 MHz in high energy high intensity proton linear accelerator proposed to be built for ADSS/SNS programme in India and Project-X at Fermilab, USA. This IOT based amplifier provides up to 60 kW continuous wave RF power at 700 MHz. It required various power supplies, LCW cooling and forced air cooling for its operation. The auxiliary power supplies like Grid, Filament and Ion-pump, are floated and mounted on an isolated frame, i.e., HV deck. The mains inputs are electrically isolated by means of isolation transformer. Also, a Programmable Logic Controller (PLC) based interlocks along with high voltage collector power supply has been designed and developed for the safe operation of the RF amplifier. This paper discusses about various developments and energization of the IOT based RF amplifier with high power dummy load. (author)

  12. The Pathological and Physiological Roles of IL-6 Amplifier Activation

    Directory of Open Access Journals (Sweden)

    Masaaki Murakami, Toshio Hirano

    2012-01-01

    Full Text Available The NFκB-triggered positive feedback loop for IL-6 signaling in type 1 collagen+ non-immune cells (IL-6 amplifier was first discovered to be a synergistic signal that is activated following IL-17A and IL-6 stimulation in type 1 collagen+ non-immune cells. Subsequent disease models have shown that it can also be stimulated by the simultaneous activation of NFκB and STAT3, functions as a local chemokine inducer, and acts as a mechanism for local inflammation, particularly chronic ones like rheumatoid arthritis and a multiple sclerosis. Moreover, we have recently shown that hyper activation of the IL-6 amplifier via regional neural activation establishes a gateway for immune cells including autoreactive T cells to pass the blood-brain barrier at dorsal vessels in 5th lumbar cord. Here we review how the IL-6 amplifier is activated by neural activation and the physiological relevance of the gateway to the central nervous system. Accumulating evidences continues to suggest that the IL-6 amplifier offers a potential molecular mechanism for the relationship between neural activation and the development of inflammatory diseases, which could establish a new interdisciplinary field that fuses neurology and immunology.

  13. Sexing birds using random amplified polymorphic DNA (RAPD) markers

    NARCIS (Netherlands)

    Lessells, C.M.; Mateman, A.C.

    1998-01-01

    We used random amplified polymorphic DNA (RAPD) markers to sex birds from small tissue (usually blood) samples. Arbitrarily chosen 10-mer PCR primers were screened with DNA from known-sex individuals for the production of a bright female-specific band. Suitable primers were found for seven bird spec

  14. Electron motion in an elliptically polarized free electron laser amplifier

    International Nuclear Information System (INIS)

    The equation of motion for an electron in a free electron laser amplifier are written in hamiltonian form, and exactly solved for the circular polarized case. Successively, an approximate solution for a general polarization (elliptical or linear) and weak laser field is obtained by a relativistic generalization of the two timing technique. Finally, the theoretical perturbative results are confirmed by comparison with numerical solutions

  15. HTS dc SQUID based rf amplifier: development concept

    DEFF Research Database (Denmark)

    Prokopenko, G.V.; Shitov, S.V.; Borisenko, I.V.; Mygind, Jesper

    We present a concept of a rf amplifier based on a directly coupled dc SQUID with bicrystal junctions, which have high saturation power and can be used with SIS mixers or possibly for satellite and cellular phone communications. A novel input resonant circuit is proposed using single layer of HTS...

  16. An energy amplifier fluidized bed nuclear reactor concept

    International Nuclear Information System (INIS)

    The concept of a fluidized bed nuclear reactor driven by an energy amplifier system is described. The reactor has promising characteristics of inherent safety and passive cooling. The reactor can easily operate with any desired spectrum in order to be a plutonium burner or have it operate with thorium fuel cycle. (orig.)

  17. Semiconductor quantum dot amplifiers for optical signal processing

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Uskov, A. V.; Bischoff, Svend; Magnúsdóttir, Ingibjörg; Mørk, Jesper

    The dynamics of quantum dot semiconductor amplifiers are investigated theoretically with respect to the potential for ultrafast signal processing. The high-speed signal processing capacity of these devices is found to be limited by the wetting layer dynamics in case of electrical pumping, while...... optical pumping partly removes this limitation. Also, the possibility of using spectral hole burning for signal processing is discussed....

  18. Nonlinear carrier dynamics in a quantum dash optical amplifier

    DEFF Research Database (Denmark)

    Hansen, Per Lunnemann; Ek, Sara; Yvind, Kresten;

    2012-01-01

    Results of experimental pump-probe spectroscopy of a quantum dash optical amplifier biased at transparency are presented. Using strong pump pulses we observe a competition between free carrier absorption and two-photon induced stimulated emission that can have drastic effects on the transmission...

  19. Monolithic integrated circuit charge amplifier and comparator for MAMA readout

    Science.gov (United States)

    Cole, Edward H.; Smeins, Larry G.

    1991-01-01

    Prototype ICs for the Solar Heliospheric Observatory's Multi-Anode Microchannel Array (MAMA) have been developed; these ICs' charge-amplifier and comparator components were then tested with a view to pulse response and noise performance. All model performance predictions have been exceeded. Electrostatic discharge protection has been included on all IC connections; device operation over temperature has been consistent with model predictions.

  20. Ultrafast gain and index dynamics in quantum dot amplifiers

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Mørk, Jesper;

    1999-01-01

    The ultrafast dynamics of gain and refractive index in an InAs/GaAs quantum dot amplifier are investigated at room temperature. The gain is observed to recover with a 90 fs time constant, ruling out problems of slow carrier capture into the dots, and making this component promising for high...

  1. Gain dynamics and saturation in semiconductor quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper; Hvam, Jørn Märcher

    2004-01-01

    Quantum dot (QD)-based semiconductor optical amplifiers offer unique properties compared with conventional devices based on bulk or quantum well material. Due to the bandfilling properties of QDs and the existence of a nearby reservoir of carriers in the form of a wetting layer, QD semiconductor ...... ultrafast gain dynamics....

  2. Semiconductor optical amplifier length effects on gain dynamics

    International Nuclear Information System (INIS)

    We study theoretically semiconductor optical amplifier (SOA) length effects on gain dynamics when a short saturating pulse (pump) is either co- or counter-propagative with the probe. More specifically, we focus our attention on SOA recovery dynamics and gain overshoot. Analysis is also given when the input probe power and input pump energy are increased for different SOA lengths

  3. K-Band Traveling-Wave Tube Amplifier

    Science.gov (United States)

    Force, Dale A.; Simons, Rainee N.; Peterson, Todd T.; Spitsen, Paul C.

    2010-01-01

    A new space-qualified, high-power, high-efficiency, K-band traveling-wave tube amplifier (TWTA) will provide high-rate, high-capacity, direct-to-Earth communications for science data and video gathered by the Lunar Reconnaissance Orbiter (LRO) during its mission. Several technological advances were responsible for the successful demonstration of the K-band TWTA.

  4. HTS dc SQUID based rf amplifier: development concept

    DEFF Research Database (Denmark)

    Prokopenko, G.V.; Shitov, S.V.; Borisenko, I.V.;

    2002-01-01

    We present a concept of a rf amplifier based on a directly coupled dc SQUID with bicrystal junctions, which have high saturation power and can be used with SIS mixers or possibly for satellite and cellular phone communications. A novel input resonant circuit is proposed using single layer of HTS...

  5. Temporal and transverse coherence of self-amplified spontaneous emission

    International Nuclear Information System (INIS)

    The authors review the coherence properties of the self-amplified spontaneous emission (SASE). Temporally, SASE is similar to the spontaneous undulator radiation except that the spectral bandwidth is about ten times narrower compared with typical undulator radiation. The situation is quite different in the transverse dimension, where SASE is fully coherent

  6. Processing of optical combs with fiber optic parametric amplifiers

    Czech Academy of Sciences Publication Activity Database

    Slavík, Radan; Kakande, J.; Richardson, D.J.; Petropoulos, P.

    2012-01-01

    Roč. 20, č. 9 (2012), s. 10059-10070. ISSN 1094-4087 Institutional support: RVO:67985882 Keywords : Fiber-optic parametric amplifier * Phase sensitive * Spectral coverage Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.546, year: 2012

  7. Prototype Small Footprint Amplifier for Piezoelectric Deformable Mirrors

    Science.gov (United States)

    Caputa, Kris; Herriot, Glen; Niebergal, Joel; Zielinski, Adam

    2011-09-01

    AO subsystems of the ELT observatories will incorporate deformable mirrors with an order of magnitude larger number of piezoelectric actuators than the AO systems currently deployed. Simply scaling up the drive electronics that are presently available commercially would substantially drive up the AO cost, pose unacceptably high demands for the supply power and heat dissipation, and occupy large physical volume. We have set out to prototype a high voltage amplifier that is compact enough to allow packaging 100 amplifier channels on a single 6U Eurocard with the goal to have a DM drive channel density of 1200 per 6U VME crate. Individual amplifier circuits should be driven by a multichannel A/D converter, consume no more than 0.5W from the +/-400V power supply, be slew rate limited in hardware, and be short-circuit protected. The component cost should be an order of magnitude less than the integrated circuit high voltage amplifiers currently on the market. We started out with modeling candidate circuits in SPICE, then built physical prototypes using inexpensive off the shelf components. In this paper we present experimental results of exposing several prototype circuits to both normal operating conditions and foreseeable fault conditions. The performance is evaluated against the AO requirements for the output range and bandwidth and the DM actuator safety requirements.

  8. Can El Nino Amplify the Solar Forcing of Climate?

    Science.gov (United States)

    Ruzmaikin, A.

    1999-01-01

    ENSO (El Nino and the Southern Oscillation) is considered as a stochastic driver that excites the atmospheric anomaly states, such as Pacific North American pattern. This can make the 11 year solar activity forcing feasible to climate through stochastic resonance -- a phenomenon that amplifies a weak input to a nonlinear bistable system by the assistance of noise.

  9. Amplified spontaneous emission pulses for high-power supercontinuum generation

    Directory of Open Access Journals (Sweden)

    Huan Huan Liu

    2016-03-01

    Full Text Available The authors demonstrate an incoherent light source based on a reflective semiconductor optical amplifier as pump for high-power supercontinuum generation for the first time. The obtained power level is about 160 mW and 20 dB spectral bandwidth is around 170 nm.

  10. Effects of gamma radiation on commercial operational amplifiers

    International Nuclear Information System (INIS)

    The operational amplifiers are widely used in nuclear instrumentation. Their applications span the signal conditioning circuits, analog instrumentation, amplifiers, converters, oscillators and others. If an operational amplifier is used to work in a radiation environment, the device suffers degradation in its performance leading to the bad work in the systems. Some of these devices are designed as rad-hard components and therefore the effects of radiation damage are minimized, however its main disadvantage is the high cost and difficult to find in the market. As an alternative one can use the conventional electronic components available in the market and named COTS (Commercially Available Off-The-Shelf) but they must be tested under a radiation environment. In this work the effect of the radiation damage is studied in two typical operational amplifiers. Some electric parameters of these devices were measured for different gamma radiation doses and they were working at different input signal frequencies. A 60Co isotopic radiation source was used and the results show that there is a certain degradation of the device depending on the radiation absorbed dose. (author)

  11. The Gain Dependence of the Power Transient in Raman Amplifier

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    It is observed that the amplitude of the power transient overshoot depends on the gain of the amplifier when the input signal powers are the same. The other system parameters, such as the input pump power and fiber length, have no effects on it.

  12. On the unlimited gain of a nonlinear parametric amplifier

    DEFF Research Database (Denmark)

    Sorokin, Vladislav

    2014-01-01

    nonlinearbehavior when amplitude of their response is sufficiently large. The modified method of direct separa-tion of motions is employed to study the considered system. As the result it is obtained that steady-stateamplitude of the nonlinear parametric amplifier response can reach large values in the case...

  13. Pulsed hydrogen fluoride laser oscillator-amplifier experiments

    International Nuclear Information System (INIS)

    Pulsed HF chemical laser oscillator energies were scaled from millijoules to several kilojoules over the period 1970-1974, reaching approximately 10 J with SF6 and transverse discharges, and using electron-beam initiation and elemental F2 above 1000J. This demonstrated scalability to large energy with acceptable electrical efficiency is only one prerequisite for application of this gas laser in fusion; equally important matters are achievement of focusable, approximately 1 ns pulses, couplable to light-element targets, all from an affordable system. Exploratory MOPA experiments are reported which address control of HF laser beam focusability and pulse duration, using SF6-based experimental oscillator--amplifier sequences and Pockels' cell switching. Simultaneous multiline lasing with 2.6 less than or equal to lambda less than or equal to 3.1 μm and high specific gain and energy density are particularly important factors encountered with HF, where amplifier pumping and lasing occur in a substantially cw temporal relationship, even in less than 100 ns bursts. Time-resolved SF6--HI oscillator spectra contain 27 simultaneous lines from six vibrational bands. An apertured, SF6-hydrocarbon pin-discharge oscillator generates approximately 10 mJ of TEM00 radiation, which is amplified to approximately 1 J in approximately 150 ns by a TEA amplifier and p

  14. A fully integrated 16 channel digitally trimmed pulse shaping amplifier

    International Nuclear Information System (INIS)

    A fully integrated CMOS pulse shaping amplifier has been developed at LBL. All frequency dependent networks are included on the chip. Provision is made for tuning to compensate for process variations. The overall architecture and details of the circuitry are discussed. Test results are presented

  15. Giant Geometrically Amplified Piezoresistance in Metal-Semiconductor Hybrid Resistors

    DEFF Research Database (Denmark)

    Hansen, Ole; Reck, Kasper; Thomsen, Erik Vilain

    2008-01-01

    We show that very high geometrically amplified piezoresistance can indeed be obtained in microstructured metal-semiconductor hybrid devices, even significantly higher amplification factors than the factor of approximately 8 demonstrated recently by Rowe and co-workers may be achieved. However, we...

  16. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    International Nuclear Information System (INIS)

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al2O3/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 x 1017 in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO3 crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies

  17. The design of a 4’th order Bandpass Butterworth filter with one operational amplifier

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    2008-01-01

    A numerical design method is presented for the design of all pole band pass active-RC filters applying just one operational amplifier. The operational amplifier model used is the integrator model: ωt/s where ωt is the unity gain fre-quency. The design method is used for the design of a fourth order...... band pass filter with Butterworth poles applying just one operational amplifier coupled as a unity gain amplifier. The unity gain amplifiers have the advantage of providing low power consumption, yielding a large dynamic range, sometimes simplifying the amplifier design and being usable over a larger...

  18. Design and tests of offset-compensated in-pixel amplifiers for CMOS pixel sensors

    International Nuclear Information System (INIS)

    This paper presents novel in-pixel amplifiers for CMOS pixel sensors. Two kinds of offset-compensated amplifiers allow the sensors to achieve a high signal-to-noise ratio. Based on theoretical analysis, the gain of the input offset-compensated amplifier is less sensitive to threshold voltage variation than the output offset-compensated amplifier. A 12μm pitch CMOS pixel sensor with the input offset-compensated amplifier was therefore designed and fabricated in a 0.13μm CMOS technology. Measurements indicate that the implementation of this amplifier can result in a high signal-to-noise ratio for a CMOS pixel sensor.

  19. Criterion of transverse coherence of self-amplified spontaneous emission in high gain free electron laser amplifiers

    International Nuclear Information System (INIS)

    In a high gain free electron laser amplifier based on Self-Amplified Spontaneous Emission (SASE) the spontaneous radiation generated by an electron beam near the undulator entrance is amplified many orders of magnitude along the undulator. The transverse coherence properties of the amplified radiation depends on both the amplification process and the coherence of the seed radiation (the undulator radiation generated in the first gain length or so). The evolution of the transverse coherence in the amplification process is studied based on the solution of the coupled Maxwell-Vlasov equations including higher order transverse modes. The coherence of the seed radiation is determined by the number of coherent modes in the phase space area of the undulator radiation. We discuss the criterion of transverse coherence and identify governing parameters over a broad range of parameters. In particular we re-examine the well known emittance criterion for the undulator radiation, which states that full transverse coherence is guaranteed if the rms emittance is smaller than the wavelength divided by 4π. It is found that this criterion is modified for SASE because of the different optimization conditions required for the electron beam. Our analysis is a generalization of the previous study by Yu and Krinsky for the case of vanishing emittance with parallel electron beam. Understanding the transverse coherence of SASE is important for the X-ray free electron laser projects now under consideration at SLAC and DESY

  20. Amplifier Module for 260-GHz Band Using Quartz Waveguide Transitions

    Science.gov (United States)

    Padmanabhan, Sharmila; Fung, King Man; Kangaslahti, Pekka P.; Peralta, Alejandro; Soria, Mary M.; Pukala, David M.; Sin, Seth; Samoska, Lorene A.; Sarkozy, Stephen; Lai, Richard

    2012-01-01

    Packaging of MMIC LNA (monolithic microwave integrated circuit low-noise amplifier) chips at frequencies over 200 GHz has always been problematic due to the high loss in the transition between the MMIC chip and the waveguide medium in which the chip will typically be used. In addition, above 200 GHz, wire-bond inductance between the LNA and the waveguide can severely limit the RF matching and bandwidth of the final waveguide amplifier module. This work resulted in the development of a low-loss quartz waveguide transition that includes a capacitive transmission line between the MMIC and the waveguide probe element. This capacitive transmission line tunes out the wirebond inductance (where the wire-bond is required to bond between the MMIC and the probe element). This inductance can severely limit the RF matching and bandwidth of the final waveguide amplifier module. The amplifier module consists of a quartz E-plane waveguide probe transition, a short capacitive tuning element, a short wire-bond to the MMIC, and the MMIC LNA. The output structure is similar, with a short wire-bond at the output of the MMIC, a quartz E-plane waveguide probe transition, and the output waveguide. The quartz probe element is made of 3-mil quartz, which is the thinnest commercially available material. The waveguide band used is WR4, from 170 to 260 GHz. This new transition and block design is an improvement over prior art because it provides for better RF matching, and will likely yield lower loss and better noise figure. The development of high-performance, low-noise amplifiers in the 180-to- 700-GHz range has applications for future earth science and planetary instruments with low power and volume, and astrophysics array instruments for molecular spectroscopy. This frequency band, while suitable for homeland security and commercial applications (such as millimeter-wave imaging, hidden weapons detection, crowd scanning, airport security, and communications), also has applications to

  1. Low Power Broadband Low-Noise Amplifiers from 1-300GHz Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A number of low noise amplifier technologies exist at a variety of maturity levels and with a variety of strengths and limitations. The most mature amplifier...

  2. A numerical design approach for single amplifier, Active-RC Butterworth filter of order 5

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    2007-01-01

    A design method is presented for the design of all pole lowpass active-RC filters applying operational amplifiers. The operational amplifier model used is the integrator model: omegat/s where omegat is the unity gain frequency. The design method is used for the design of a fifth order Butterworth...... filter applying just one operational amplifier coupled as a unity gain amplifier. It is shown that the influence from the real operational amplifier may be reduced by trimming just one resistor in the circuit. The unity gain amplifiers have the advantage of providing low power consumption, yielding...... a large dynamic range, sometimes simplifying the amplifier design and being usable over a larger frequency range than conventional constant gain amplifiers. The Schoeffler sensitivity index is used as a basis for a sensitivity comparison with other similar filters reported in the literature. © 2007 IEEE....

  3. Linear mode competition studies in multi-cavity gyroklystron amplifiers

    International Nuclear Information System (INIS)

    In multi-cavity gyroklystron amplifiers, the drift sections between cavities are generally designed to cutoff the mode of interest; it is the isolation between cavities that keeps the circuit from oscillating as a whole. Higher frequency modes, however, are not cutoff in the drift tubes. Because of their long effective length, these modes may have low start oscillation currents. Using the scattering matrix method, the authors find the modes in a complex, cylindrical cavity as an expansion in transverse eigenfunctions. They then compute the start oscillation current by numerically integrating the particles through the circuit. The start oscillation current determines the level of wall loading needed to suppress the mode. Results are presented for the two cavity gyroklystron amplifier to be used in an initial University of Maryland experiments. Curves of start oscillation current vs. magnetic field are shown for selected modes with azimuthal mode numbers of 0,1, and 2

  4. Design of a 140 GHz, 100 W Gyroklystron Amplifier

    Science.gov (United States)

    Joye, Colin; Shapiro, Michael; Sirigiri, Jagadishwar; Temkin, Richard

    2004-11-01

    We present the design and the simulation results for a 140 GHz, 100 watt CW gyroklystron amplifier for use in Dynamic Nuclear Polarization (DNP) experiments. The amplifier was designed for a 15 kV, 150 mA annular electron beam and simulations show a saturated gain of 36 dB at a pitch factor of 1.5 for the TE02 mode with an efficiency of 6% and output power of 130 watts. The -3dB bandwidth is 1 GHz (0.7%) and 1.2 GHz of bandwidth is available at the 50-watt level. This design is also capable of emitting pulses on the nanosecond scale. The circuit consists of an input cavity, three bunching cavities and an output cavity with a nonlinear uptaper. This project is supported by NIBIB grant #5R01EB1965.

  5. PIC code simulations on NRL gyro-amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.J. [Science Applications International Corp., McLean, VA (United States); Ahn, S.; Danly, B.G.; Levush, B.; Parker, R.K. [Naval Research lab., Washington, DC (United States). Vacuum Electronics Branch; Ganguly, A.K.; Park, G.S. [Omega-P, Inc., New Haven, CT (United States)

    1996-12-31

    Developments on high power millimeter wave gyro-amplifiers are currently underway at NRL. Recent experiments on a folded waveguide circuit demonstrated a strong electron cyclotron instability, producing a high efficiency (> 20%) oscillation at 32.8 GHz. The interaction was first predicted from a particle-in-cell (PIC) code, MAGIC and agreed reasonably well with the measured performance. A design study on a 200 kW, 35 GHz two-cavity gyroklystron amplifier is in progress by the use of slow-time scale non-linear codes for beam-wave interactions, a finite element electromagnetic code, HFSS and a CASCADE code for cold cavity problems. MAGIC and SOS are also utilized to compare with those predictions. PIC-code simulation techniques and its comparison with measurements will be presented.

  6. Design of high efficiency, high harmonic gyro-amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, W.; Destler, W.W. [Univ. of Maryland, College Park, MD (United States)

    1994-12-31

    In this paper, a novel hybrid microwave amplifier that utilizes the axial bunching mechanism of klystrons in conjunction with the energy extraction mechanism of cyclotron resonance masers is introduced. A simple analytic model is presented to demonstrate the viability of the scheme and explore limits of the device configuration. Adopting a single particle approach, numerical simulations are used to demonstrate bunching in physical space, small-signal stability, and large-signal efficiency. Interactions are considered between beams with realistic velocity spreads and both right-circular and Vane-type resonator output cavities. A concrete theoretical example of a 4th harmonic amplifier that is capable of producing 1 MW at 11 GHz with 40% efficiency is given. Comparisons are made with the more conventional gyroklystron approach. A second design at the 10th harmonic will also be described. It is shown that this new configuration enables the design of efficient, high harmonic devices over a wide range of parameters.

  7. A Novel Frequency Compensation Technique for Three-Stage Amplifier

    Institute of Scientific and Technical Information of China (English)

    LI Qiang; YI Jun; LI Zhao-ji; ZHANG Bo; FANG Jian; LUO Ping

    2005-01-01

    A novel frequency compensation technique for three-stage amplifier with dual complex pole-zero (DCP) cancellation is proposed. It uses one pair of complex zeros to cancel one pair of complex poles, resulting in feature that frequency response of the three-stage amplifier exhibits that of a single-pole system. Thus the gain-bandwidth (GBW) is expected to be increased several times compared to the conventional nested miller compensation (NMC) approach. Moreover, this technique requires only one very small compensation capacitor even when driving a big load capacitor. A GBW 4.63 MHz, DC gain 100 dB, PM 90o and power dissipation 0.87 mW can be achieved for a load capacitor 100 pF with a single Miller compensation capacitor 2 pF at a ±1V supply in a standard 0.6-μm CMOS technology.

  8. KfR amplifier optimization for IFE driver system

    International Nuclear Information System (INIS)

    A comprehensive, electricity to photons on target, model for the efficiency of a large e-beam pumped, angularly multiplexed KrF amplifier system is presented in this paper. The model is used to systematically and quantitatively examine the influence of the major parameters influencing system efficiency. Conclusions are drawn about optimum amplifier parameters for a power plant driver. Three important aspects of the driver system design for an IFE power plant are: high operating efficiency, low operating costs, and low capital cost. In this paper, the authors have focused on the overall driver system operating efficiency, and its optimization in the context of technology which must have the potential for long life, so it may have low operating costs, and the potential for low capital cost when produced in the quantity necessary for a full scale power plant

  9. Investigation of 7 GHz high power pulsed magnicon amplifier

    International Nuclear Information System (INIS)

    The magnicon is a microwave amplifier in which the beam is modulated by means of its circular deflection. Presented in this reports is a frequency doubling amplifier developed as a prototype of the microwave energy source for linear colliders. The magnicon is driven by a beam with a power of up to 100 MW and a microperveance of 0.83, the source of which is a thermionic electron gun with a very high convergence (up to 2000:1 in area). During the investigation the following results were obtained: a power of 30 MW, an efficiency of 35%, and a gain of 55 dB. This paper presents the tube design, problems faced and overcome during the investigation, and possible methods of further improving the device

  10. A novel power amplifier structure for RFID tag applications

    International Nuclear Information System (INIS)

    A novel matching method between the power amplifier (PA) and antenna of an active or semi-active RFID tag is presented. A PCB dipole antenna is used as the resonance inductor of a differential power amplifier. The total PA chip area is reduced greatly to only 240 × 70 μm2 in a 0.18 μm CMOS process due to saving two on-chip integrated inductors. Operating in class AB with a 1.8 V supply voltage and 2.45 GHz input signal, the PA shows a measured output power of 8 dBm at the 1 dB compression point. (semiconductor integrated circuits)

  11. A HIGHLY ADAPTIVE OPERATIONAL AMPLIFIER WITH RECYCLING FOLDED CASCODE TOPOLOGY

    Directory of Open Access Journals (Sweden)

    Saumya Vij

    2014-07-01

    Full Text Available This paper presents a highly adaptive operational amplifier with high gain, high bandwidth, high speed and low power consumption. By adopting the recycling folded cascode topology along with an adaptive-biasing circuit, this design achieves high performance in terms of gainbandwidth product (GBW and slew rate (SR. This single stage op-amp has been designed in 0.18µm technology with a power supply of 1.8V and a 5pF load. The simulation results show that the amplifier achieved a GBW of 335.5MHz, Unity Gain Bandwidth of 247.1MHz and a slew rate of 92.8V/µs.

  12. Modal instabilities in very large mode area rod fiber amplifiers

    DEFF Research Database (Denmark)

    Jørgensen, Mette Marie; Hansen, Kristian Rymann; Laurila, Marko;

    finite element method to allow complex micro structured fibers to be considered. Thereby the modal instability threshold is estimated for very large mode area fiber amplifiers of various photonic crystal fiber designs. Experimentally the modal instability threshold for very large mode area fiber......-100 microns, by reducing all index contrasts to very low values, and possibly utilizing advanced photonic-band gap cladding designs to filter out higher-order modes [2], see Fig. 1. The guided modes of such cores are very sensitive to perturbations. An unavoidable perturbation at large average power is the...... modal instability [3-5], represented in Fig. 2 as the growth of the higher order mode content. This is a fundamental obstacle for power scaling in fiber amplifiers that significantly reduces beam quality and stability. We combine analytic considerations for thermally induced mode coupling with the...

  13. Precision Instrumentation Amplifiers and Read-Out Integrated Circuits

    CERN Document Server

    Wu, Rong; Makinwa, Kofi A A

    2013-01-01

    This book presents innovative solutions in the design of precision instrumentation amplifier and read-out ICs, which can be used to boost millivolt-level signals transmitted by modern sensors, to levels compatible with the input ranges of typical Analog-to-Digital Converters (ADCs).  The discussion includes the theory, design and realization of interface electronics for bridge transducers and thermocouples. It describes the use of power efficient techniques to mitigate low frequency errors, resulting in interface electronics with high accuracy, low noise and low drift. Since this book is mainly about techniques for eliminating low frequency errors, it describes the nature of these errors and the associated dynamic offset cancellation techniques used to mitigate them.  Surveys comprehensively offset cancellation and accuracy improvement techniques applied in precision amplifier designs; Presents techniques in precision circuit design to mitigate low frequency errors in millivolt-level signals transmitted by ...

  14. 5 Watt GaN HEMT Power Amplifier for LTE

    OpenAIRE

    Niotaki, K.; Collado, A.; Georgiadis, A.; Vardakas, J.

    2014-01-01

    This work presents the design and implementation of a stand-alone linear power amplifier at 2.4 GHz with high output power. A GaN HEMT transistor is selected for the design and implementation of the power amplifier. The device exhibits a gain of 11.7 dB and a drain efficiency of 39% for an output power of 36.7 dBm at 2.4 GHz for an input power of 25dBm. The carrier to intermodulation ratio is better than 25 dB for a two tone input signal of 25 dBm of total power and a spacing of 5 MHz. The fa...

  15. Multilayer-graphene-based amplifier of surface acoustic waves

    International Nuclear Information System (INIS)

    The amplification of surface acoustic waves (SAWs) by a multilayer graphene (MLG)-based amplifier is studied. The conductivity of massless carriers (electrons or holes) in graphene in an external drift electric field is calculated using Boltzmann’s equation. At some carrier drift velocities, the real part of the variable conductivity becomes negative and MLG can be employed in SAW amplifiers. Amplification of Blustein’s and Rayleigh’s SAWs in CdS, a piezoelectric hexagonal crystal of the symmetry group C6v, is considered. The corresponding equations for SAW propagation in the device are derived and can be applied to other substrate crystals of the same symmetry. The results of the paper indicate that MLG can be considered as a perspective material for SAW amplification and related applications

  16. Temperature compensated log-ratio amplifiers for spectrophotometry

    International Nuclear Information System (INIS)

    In spectrophotometry, a log-ratio amplifier is required to measure the absorbance of media. In this paper we show that the inherent logarithmic properties of silicon junction devices can be used to provide the required signal. Readily available in monolithically matched pairs, log-ratio amplifiers are low in cost and can be easily compensated for temperature variation. Here we discuss their basic properties and the techniques for obtaining both thermal and dynamic stability. By proper choice of circuit configuration, the dynamic range can be extended without seriously affecting the overall accuracy. Log conformity to within 1% in 4 decades over the temperature range 200C - 400C can be achieved with commercially available silicon devices. (author)

  17. Multi Carrier Modulator for Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael Andreas E.

    2008-01-01

    While switch-mode audio power amplifiers allow compact implementations and high output power levels due to their high power efficiency, they are very well known for creating electromagnetic interference (EMI) with other electronic equipment, in particular radio receivers. Lowering the EMI of switch......-mode audio power amplifiers while keeping the performance measures to excellent levels is therefore of high general interest. A modulator utilizing multiple carrier signals to generate a two level pulse train will be shown in this paper. The performance of the modulator will be compared in simulation to...... existing modulation topologies. The lower EMI as well as the preserved audio performance will be shown in simulation as well as in measurement results on a prototype....

  18. A High Power Amplifier for a Single Mode 1064 Laser

    Science.gov (United States)

    Stites, R. W.; O'Hara, K. M.

    2011-05-01

    We report on the construction of a high power amplifier system for a single mode 1064 nm laser. At the heart of this device is a 0.27% neodymium doped yttrium orthovanadate crystal that is double end pumped by two 30 Watt broadband diode arrays at 808 nm. For a 50 Watt TEM00 single freqency seed laser, we have observed an amplified power output in excess of 60 Watts for single pass configuration. A further increase in output power can be attained by retroreflecting the beam back through the crystal a second time. Such a device has direct application in the construction of optical lattices where high power single frequency lasers are required.

  19. Low-voltage CMOS operational amplifiers theory, design and implementation

    CERN Document Server

    Sakurai, Satoshi

    1995-01-01

    Low-Voltage CMOS Operational Amplifiers: Theory, Design and Implementation discusses both single and two-stage architectures. Opamps with constant-gm input stage are designed and their excellent performance over the rail-to-rail input common mode range is demonstrated. The first set of CMOS constant-gm input stages was introduced by a group from Technische Universiteit, Delft and Universiteit Twente, the Netherlands. These earlier versions of circuits are discussed, along with new circuits developed at the Ohio State University. The design, fabrication (MOSIS Tiny Chips), and characterization of the new circuits are now complete. Basic analog integrated circuit design concepts should be understood in order to fully appreciate the work presented. However, the topics are presented in a logical order and the circuits are explained in great detail, so that Low-Voltage CMOS Operational Amplifiers can be read and enjoyed by those without much experience in analog circuit design. It is an invaluable reference boo...

  20. Wide bandwidth transimpedance amplifier for extremely high sensitivity continuous measurements

    Science.gov (United States)

    Ferrari, Giorgio; Sampietro, Marco

    2007-09-01

    This article presents a wide bandwidth transimpedance amplifier based on the series of an integrator and a differentiator stage, having an additional feedback loop to discharge the standing current from the device under test (DUT) to ensure an unlimited measuring time opportunity when compared to switched discharge configurations while maintaining a large signal amplification over the full bandwidth. The amplifier shows a flat response from 0.6Hzto1.4MHz, the capability to operate with leakage currents from the DUT as high as tens of nanoamperes, and rail-to-rail dynamic range for sinusoidal current signals independent of the DUT leakage current. Also available is a monitor output of the stationary current to track experimental slow drifts. The circuit is ideal for noise spectral and impedance measurements of nanodevices and biomolecules when in the presence of a physiological medium and in all cases where high sensitivity current measurements are requested such as in scanning probe microscopy systems.

  1. Optical steganography based on amplified spontaneous emission noise.

    Science.gov (United States)

    Wu, Ben; Wang, Zhenxing; Tian, Yue; Fok, Mable P; Shastri, Bhavin J; Kanoff, Daniel R; Prucnal, Paul R

    2013-01-28

    We propose and experimentally demonstrate an optical steganography method in which a data signal is transmitted using amplified spontaneous emission (ASE) noise as a carrier. The ASE serving as a carrier for the private signal has an identical frequency spectrum to the existing noise generated by the Erbium doped fiber amplifiers (EDFAs) in the transmission system. The system also carries a conventional data channel that is not private. The so-called "stealth" or private channel is well-hidden within the noise of the system. Phase modulation is used for both the stealth channel and the public channel. Using homodyne detection, the short coherence length of the ASE ensures that the stealth signal can only be recovered if the receiver closely matches the delay-length difference, which is deliberately changed in a dynamic fashion that is only known to the transmitter and its intended receiver. PMID:23389187

  2. A CMOS low-noise instrumentation amplifier using chopper modulation

    DEFF Research Database (Denmark)

    Nielsen, Jannik Hammel; Bruun, Erik

    2005-01-01

    This paper describes a low-power, low-noise chopper stabilized CMOS instrumentation amplifier for biomedical applications. Low thermal noise is achieved by employing MOSTs biased in the weak/moderate inversion region, whereas chopper stabilization is utilized to shift 1/f-noise out of the signal...... band hereby ensuring overall low noise performance. The resulting equivalent input referred noise is approximately 7 nV/rootHz for a chopping frequency of 20 kHz. The amplifier operates from a modest supply voltage of 1.8 V, drawing 136 muA of current thus consuming 245 muW of power. The gain is 72.5 d...

  3. Multilayer-graphene-based amplifier of surface acoustic waves

    Directory of Open Access Journals (Sweden)

    Stanislav O. Yurchenko

    2015-05-01

    Full Text Available The amplification of surface acoustic waves (SAWs by a multilayer graphene (MLG-based amplifier is studied. The conductivity of massless carriers (electrons or holes in graphene in an external drift electric field is calculated using Boltzmann’s equation. At some carrier drift velocities, the real part of the variable conductivity becomes negative and MLG can be employed in SAW amplifiers. Amplification of Blustein’s and Rayleigh’s SAWs in CdS, a piezoelectric hexagonal crystal of the symmetry group C6v, is considered. The corresponding equations for SAW propagation in the device are derived and can be applied to other substrate crystals of the same symmetry. The results of the paper indicate that MLG can be considered as a perspective material for SAW amplification and related applications.

  4. Multilayer-graphene-based amplifier of surface acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Yurchenko, Stanislav O., E-mail: st.yurchenko@mail.ru; Komarov, Kirill A. [Bauman Moscow State Technical University, 2-nd Baumanskaya str. 5, Moscow 105005 (Russian Federation); Pustovoit, Vladislav I. [Scientific and Technological Center of Unique Instrumentation, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-05-15

    The amplification of surface acoustic waves (SAWs) by a multilayer graphene (MLG)-based amplifier is studied. The conductivity of massless carriers (electrons or holes) in graphene in an external drift electric field is calculated using Boltzmann’s equation. At some carrier drift velocities, the real part of the variable conductivity becomes negative and MLG can be employed in SAW amplifiers. Amplification of Blustein’s and Rayleigh’s SAWs in CdS, a piezoelectric hexagonal crystal of the symmetry group C{sub 6v}, is considered. The corresponding equations for SAW propagation in the device are derived and can be applied to other substrate crystals of the same symmetry. The results of the paper indicate that MLG can be considered as a perspective material for SAW amplification and related applications.

  5. Development of a 20-W solid-state S-band power amplifier

    Science.gov (United States)

    Vandercapellen, A. G.

    1972-01-01

    As an alternative to the use of traveling wave tube amplifiers in spacecraft with long life mission requirements, a solid state S band amplifier was developed. A solid state amplifier with an output of 20 W at 2295 MHz, a dc/RF efficiency of 38%, and a gain of 27 dB was developed. The physical and electrical performance of the solid state amplifier are described.

  6. Frequency Response Of Series And Parallel Combination Of Two Single Feedback Class D Amplifier

    OpenAIRE

    R. Sivarajan; K. R. Padmavathy; A.kasthoory; N. Santha; S. Subashri

    2015-01-01

    Amplifier is generally used to increase the amplitude of the signal. Consider the audio signal, if the amplitude of the audio signal is increased, then automatically loudness of the signal is increased. Class D Amplifier (CDA) consists of integrator, PWM modulator and output stage. This system can be defined as a open loop CDA system. The main factor to be considered for any amplifier circuit is the gain which is obtained by frequency response. To improve the gain of the amplifier, ...

  7. A low noise charge sensitive amplifier for use in vacuum photo diode readout

    International Nuclear Information System (INIS)

    The amplifier described consists of a charge sensitive pre-amplifier optimised for low noise with low values of input shunt capacitance, and a shaping amplifier providing both differentiation and integration. Amplifier gain is adjustable up to a maximum of approximately 100 μV/electron with a rise time of 2 μS to the peak of the output voltage, and with an open circuit input noise level of 150 electrons RMS. (author)

  8. The matching condition for optimum thermal noise performance of F.E.T. charge amplifiers

    International Nuclear Information System (INIS)

    Amplifiers in the charge amplifier configuration are being used extensively in the readout of solid state detectors. The majority of these amplifiers are built using a Field Effect Transistor input device. To achieve optimum noise performance, there is an important matching condition between the capacitance of the amplifier input device and that of the detector. In the paper, the matching condition is derived and the consequences are discussed. (author)

  9. AutoAmp : An Open-Source Analog Amplifier Design Tool - For Classroom and Lab Purposes

    OpenAIRE

    Patri, Om Prasad; Rao, K. Sanmukh

    2012-01-01

    This correspondence presents an open-source tool AutoAmp developed at the Indian Institute of Technology, Guwahati. It is available at http://sourceforge.net/projects/autoamp-iitg/ This tool helps the user to design different types of electronic amplifiers, using solid state devices, for a given specification. It can handle several types of designs namely common-emitter BJT amplifier (single and two-stage), operational amplifiers (inverting and non-inverting) and power amplifier. Not only doe...

  10. Extraction of PCR-amplifiable genomic DNA from Bacillus anthracisspores

    Energy Technology Data Exchange (ETDEWEB)

    Torok, Tamas

    2003-05-19

    Bacterial endospore disruption and nucleic acid extractionresulting in DNA of PCR-amplifiable quality and quantity are not trivial.Responding to the needs of the Hazardous Materials Response Unit (HMRU),Laboratory Division, Federal Bureau of Investigation, protocols weredeveloped to close these gaps. Effectiveness and reproducibility of thetechniques were validated with laboratory grown pure spores of Bacillusanthracis and its close phylogenetic neighbors, and with spiked soils anddamaged samples.

  11. Minimum uncertainty coherent states attached to nondegenerate parametric amplifiers

    International Nuclear Information System (INIS)

    Exact analytical solutions for the two-mode nondegenerate parametric amplifier have been obtained by using the transformation from the two-dimensional harmonic oscillator Hamiltonian. Some important physical properties such as quantum statistics and quadrature squeezing of the corresponding states are investigated. In addition, these states carry classical features such as Poissonian statistics and minimize the Heisenberg uncertainty relation of a pair of the coordinate and the momentum operators. (author)

  12. Optically amplified free-space optical communication systems

    OpenAIRE

    Aladeloba, Abisayo Olufemi

    2013-01-01

    This thesis investigates terrestrial atmospheric FSO communication systems operating under the influence of turbulence-induced scintillation, beam spreading, optical interchannel crosstalk, amplified spontaneous emission noise and pointing errors. On-off keying-non–return-to-zero (OOK-NRZ) and digital pulse position (DPPM) are the modulation schemes used for the calculations. The possibility of using sophisticated performance evaluation techniques such as moment generating function (MGF)-...

  13. Direct synthesis of the Gaussian filter for nuclear pulse amplifiers

    International Nuclear Information System (INIS)

    The Gaussian pulse forming networks which can be suitably realized by active filters are derived based on the frequency domain analysis. The frequency characteristics and the output waveforms of the results are calculated, and show the favourable features of the filter for nuclear pulse amplifiers. Calculations on the effects of the rise time variations of the detector signal upon the pulse peak height are also carried out. (Auth.)

  14. Low Noise Current Amplifier Based on Mesoscopic Josephson Junction

    OpenAIRE

    Delahaye, Julien; Hassel, J.; Lindell, Rene; Sillanpää, Mika; Paalanen, Mikko; Seppä, Heikki; Hakonen, Pertti J.

    2003-01-01

    We utilize the band structure of a mesoscopic Josephson junction to construct low noise amplifiers. By taking advantage of the quantum dynamics of a Josephson junction, i.e. the interplay of interlevel transitions and the Coulomb blockade of Cooper pairs, we create transistor-like devices, Bloch oscillating transistors, with considerable current gain and high input impedance. In these transistors, correlated supercurrent of Cooper pairs is controlled by a small base current made of single ele...

  15. CHAOTIC DATA COMMUNICATION SYSTEM DESIGN BY USING RAMAN AMPLIFIER

    OpenAIRE

    Remzi YILDIRIM; ÇELEBİ, Fatih V.

    2010-01-01

    ABSTRACT In this study, an 80 km. long fiber-optic data communication system is designed by using Raman amplifier. Chaotic communication technique is used contrary to regular data communication principles. The  components of the chaotic signal are the optical noise by AWGN (Additive White Gaussian Noise,AWGN) technique and ONA (Optical Noise Adder,ONA) in addition to the modulated signal which is obtained by using external optical modulator. Non-return to zero (NRZ) technique is selected...

  16. Test Of A Microwave Amplifier With Superconductive Filter

    Science.gov (United States)

    Bhasin, K. B.; Toncich, S. S.; Chorey, C. M.; Bonetti, R. R.; Williams, A. E.

    1995-01-01

    Report describes design and low-temperature tests of low-noise GaAs microwave amplifier combined with microstrip band-pass filter. Two versions of microstrip filter used in alternate tests; in one version, microstrips formed as films of high-transition-temperature superconductor Y/Ba/Cu/O on lanthanum aluminate substrate with gold film as ground plane. Other version identical except microstrips as well as ground plane made of gold, normally conductive.

  17. Recent advances in semiconductor optical amplifiers and their applications

    DEFF Research Database (Denmark)

    Stubkjær, Kristian; Mikkelsen, Benny; Djurhuus, Torsten;

    1992-01-01

    The authors review recent advances in SOAs (semiconductor optical amplifiers) and some of their applications. SOAs are under rapid development to achieve polarization independent gain, low facet reflectivities, good coupling to optical fibers, and high saturation power. The package SOA can be made...... carrier density. On the other hand, short lifetime will allow SOAs to be used as gates, modulators, detectors, and frequency converters for signals with gigabit per second data rates...

  18. Systematic Design of EMI-Resilient Negative-Feedback Amplifiers

    OpenAIRE

    van der Horst, M. J.

    2012-01-01

    The information transfer capacity of negative-feedback amplifiers, and electronic circuits in general, is limited by three fundamental limitations being noise, bandwidth, and signal power. Electromagnetic Interference (EMI) is not a fundamental limitation, but it also hampers the information transfer. EMI may have such detrimental effects that malfunctioning of the electronic circuit occurs. This may result in loss of information, or worse, possibly dangerous situations. That is a reason why ...

  19. Pulse compression method for amplified spontaneous emission smooth beams

    International Nuclear Information System (INIS)

    In order to increase the intensity on target and the coupling efficiency, based on optical gain switching theory the paper presents a method for shortening the amplified spontaneous emission (ASE) smooth pulses. The experiment has been per- formed on EMG-150, a discharge laser in the Department of Experimental Physics, University of Szeged. As a result, the pulse bandwidth is shortened to 7.5 ns from 14.5 ns. and the uniformity of the ASE beams is not affected. (authors)

  20. Squeezing with a flux-driven Josephson parametric amplifier

    OpenAIRE

    Zhong L; Menzel E.P.; Di Candia R.; Eder P.; Ihmig M.; Baust A.; Haeberlein M.; Hoffmann E; Inomata K.; Yamamoto T

    2013-01-01

    Josephson parametric amplifiers (JPA) are promising devices for applications in circuit quantum electrodynamics (QED) and for studies on propagating quantum microwaves because of their good noise performance. In this work, we present a systematic characterization of a flux-driven JPA at millikelvin temperatures. In particular, we study in detail its squeezing properties by two different detection techniques. With the homodyne setup, we observe squeezing of vacuum fluctuations by superposing s...

  1. Polymer/Perovskite Amplifying Waveguides for Active Hybrid Silicon Photonics.

    Science.gov (United States)

    Suárez, Isaac; Juárez-Pérez, Emilio J; Bisquert, Juan; Mora-Seró, Iván; Martínez-Pastor, Juan P

    2015-10-28

    The emission properties of hybrid halide perovskites are exploited to implement a stable and very low power operation waveguide optical amplifier integrated in a silicon platform. By optimizing its design with a poly(methyl methacrylate) (PMMA) encapsulation, this novel photonic device presents a net gain of around 10 dB cm(-1) and 3-4 nm linewidth with an energy threshold as low as 2 nJ pulse(-1) and exhibiting no degradation after one year. PMID:26331838

  2. Coherently driven three-level laser with parametric amplifier

    CERN Document Server

    Alebachew, E

    2005-01-01

    The aim of this paper is to study the squeezing and statistical properties of the light produced by a three-level laser whose cavity contains a parametric amplifier. We consider the case in which the top and bottom levels of the three-level atoms, in a cascade configuration, injected into the laser cavity are coupled by a strong coherent light. The maximum squeezing attainable in this quantum optical system is about 74%.

  3. Dynamic Characteristics of S-band DC SQUID Amplifier

    DEFF Research Database (Denmark)

    Prokopenko, G. V.; Shitov, S. V.; Koshelets, I. L. L. V. P.; Mygind, Jesper

    2003-01-01

    A low-noise rf amplifier based on a de SQUID (SQA) has been tested in the frequency range 3.0-4.6 GHz in the open-loop configuration. The following parameters have been measured for the single-stage balanced type SQA at 4.0 GHz: gain (12 +/- 1) dB, 3 dB bandwidth of 500 MHz and noise temperature (1...

  4. Intraband effects on ultrafast pulse propagation in semiconductor optical amplifier

    Indian Academy of Sciences (India)

    K Hussain; S K Varshney; P K Datta

    2010-11-01

    High bit-rate (>10 Gb/s) signals are composed of very short pulses and propagation of such pulses through a semiconductor optical amplifier (SOA) requires consideration of intraband phenomena. Due to the intraband effects, the propagating pulse sees a fast recovering nonlinear gain which introduces less distortion in the pulse shape and spectrum of the output pulse but introduces a positive chirping at the trailing edge of the pulse.

  5. Amplifier similariton laser with extra-broad bandwidth output pulse

    Science.gov (United States)

    Korobko, D. A.; Okhotnikov, O. G.; Zolotovskii, I. O.

    2016-03-01

    We propose an advanced scheme of amplifier similariton laser providing an output pulse spectrum much wider than the gain bandwidth. The upgrade is an additional dispersive element introduced into the cavity to locally increase the peak pulse power. The proposed scheme demonstrates a drastic increase in the output pulse spectrum width, reduction of the pulse duration, and an increase in the output peak pulse power after compression.

  6. Self-amplified spontaneous emission for short wavelength coherent radiation

    International Nuclear Information System (INIS)

    We review the recent progress in our understanding of the self-amplified spontaneous emission (SASE), emphasizing the application to short wavelength generation. Simple formulae are given for the start-up, exponential gain and the saturation of SASE. Accelerator technologies producing high brightness electron beams required for short wavelength SASE are discussed. An example utilizing electron beams from a photocathode-linac system to produce 4nm SASE in the multigigawatt range is presented

  7. Current Controlled Current Differencing Buffered Amplifier: Implementation and Applications

    Directory of Open Access Journals (Sweden)

    Sudhanshu Maheshwari

    2004-01-01

    Full Text Available A new four terminal current-controlled active element is introduced, where parasitic resistances at two current input ports are controlled leading to the definition of current-controlled current differencing buffered amplifier. Bipolar implementation and as application current-mode band-pass filter circuits are proposed. Simulation results using real device parameters are included, which show device bandwidth of 35 MHz, low total harmonic distortions, and tuning over a wide current range.

  8. Proposal for a Casimir-driven parametric amplifier

    CERN Document Server

    Imboden, M; Campbell, D K; Bishop, D J

    2014-01-01

    In this paper, we discuss a design for a MEMS parametric amplifier modulated by the Casimir force. We present the theory for such a device and show that it allows for the implementation of a very sensitive voltage measuring technique, where the amplitude of a high quality factor resonator includes a tenth power dependency on an applied DC voltage. This approach opens up a new and powerful measuring modality, applicable to other measurement types.

  9. Thermal radiation and amplified spontaneous emission from a random medium

    OpenAIRE

    Beenakker, C. W. J.

    1998-01-01

    We compute the statistics of thermal emission from systems in which the radiation is scattered chaotically, by relating the photocount distribution to the scattering matrix - whose statistical properties are known from random-matrix theory. We find that the super-Poissonian noise is that of a black body with a reduced number of degrees of freedom. The general theory is applied to a disordered slab and to a chaotic cavity, and is extended to include amplifying as well as absorbing systems. We ...

  10. A direct current amplifier with linear or logarithmic response

    International Nuclear Information System (INIS)

    The following paper examines the conditions governing the construction of an instrument with logarithmic response, capable of measuring currents between 10-10 A and 10-4 A. The development is described of a type of stabilised direct current amplifier, designed particularly to operate in a Pile control board, giving indications proportional either to the power, on to the log. of this power, and which may also be linked to an instrument for measuring reactivity. (author)

  11. A monolithic 60 GHz balanced low noise amplifier

    International Nuclear Information System (INIS)

    This paper presents a 60 GHz balanced low noise amplifier. Compared with single-ended structures, the balanced structure can obtain a better input/output return loss, a lower noise figure (NF), a 3 dB improvement of the 1 dB compression point, a 6 dB improvement of IM3 and a doubled dynamic range. Each single-ended amplifier in this paper uses a four-stage cascade structure to achieve a high gain in broadband. At the operating frequency range of 59–64 GHz, the small signal gain of the balanced amplifier is more than 20 dB. Both the input and output return losses are less than −12 dB. The output 1 dB compression power is 10.5 dBm at 60 GHz. The simulation result for the NF is better than 3.9 dB. The chip is fabricated using a 0.15 μm GaAs pHEMT process with a size of 2.25 × 1.7 mm2. (paper)

  12. Solid-state RF power amplifiers development at BARC

    International Nuclear Information System (INIS)

    The paper presents the recent developments on solid- RF power amplifiers (SSRFPA) at Bhabha Atomic Research Centre (BARC). Recent developments on solid-state RF power amplifier modules using LDMOS devices higher power output (>800) per module, high power gain (∼20 dB), and moderate DC to RF conversion efficiency (>65%). RF power combiners at various outputs (1-10 kW) at arbitrary input ports have developed. Integral power amplifiers at 325 and 352 MHz have been designed for 1, 3, 5 and 7 kW output. It also includes the 270 W, 352 MHz driver of 1 MW klystron based high power RF system. This SSRFPA has power gain of 22 dB and drain efficiency of 63%. Another RF generator of 300 W, 100 MHz has been specifically developed for RF ion-source of 14 MeV generator. The RF generator has 71 % efficiency. The paper presents details and test results of all the SSRFPA developments. (author)

  13. Quaternary climate - Terrestrial Biosphere Interaction: amplifying or stabilizing?

    Science.gov (United States)

    Claussen, Martin

    2016-04-01

    According to the Gaia hypothesis, interaction between climate and biological processes tend to homeostatically maintain, on a global scale, conditions favourable for life. Does the idea of homeostatic interaction between terrestrial biosphere and climate hold for the Quaternary glacial - interglacial changes? Interpretation of palaeoclimate and palaeobotanic evidence by using climate and Earth system models yields an interesting picture. The synergy between the sea-ice albedo - climate feedback and the taiga-tundra - climate feedback is suggested to amplify the orbitally forced climatic precession. This effect seems to be strong at regional scale, but small at global scale. Various simulations indicate that biogeophysical processes amplify the difference of some 4 to 6 K in global mean temperature between glacial and interglacial climate by some 10 percent. The combined effect of biogeophysical and biogeochemical processes, i.e. processes with involve carbon stored in biomass and soil, is less clear. Theoretical studies suggest that in pre-industrial, interglacial climate, a reduction in boreal and extratropical forests tend to cool the climate and a reduction in tropical forest, to warm the climate. Recent estimates in changes in organic carbon stored under ice sheets and in permafrost point at the possibility that the sum of all terrestrial biogeochemical processes might almost "carbon neutral" to the climate system. If corroborated, this observation would favour the assumption of a dominance of biogeophysical processes amplifying orbitally forced Quaternary climate variations.

  14. Numerical calculation of vacuum tube power amplifier mode of operation

    International Nuclear Information System (INIS)

    As result of INR RF system upgrade new vacuum tubes GI-71A and GI-57A were installed in the final and driver stages instead of GI-54A and GI-51A, manufacture of which had been stopped 20 years ago. New tubes are distinguished from former ones and a problem of optimization of the power amplifier mode of operation became the main one. This is connected not only with new type of the vacuum tubes, but also with the necessity of using, as much as possible, the former power amplifier basic hardware. The paper consists of two parts. In the first one a way of the PA vacuum tube load (equivalent resistance) calculation is considered. In the second one the model for determination of vacuum tube mode of operation is presented. By means of the model the vacuum tube specified in parameters, such as plate voltage, grid-cathode automatic bias, anode load etc, allow right now determining output parameters and efficiency of the power amplifier.

  15. Polarization-maintaining amplifier based on 3C fiber structures

    Science.gov (United States)

    Enokidani, Jun; Ito, Rumi; Sakurai, Tsutomu; Shin, Sumida; Tei, Kazuyoku

    2015-03-01

    Chirally-Coupled-Core (3C) fiber structure can preserve a single mode quality and even a linear polarization for a large core size. A principal advantage of fiber laser is its compatibility with monolithic integration and robust system. But so far, devices such as a combiner using the 3C fibers have not been reported. Here we report the first demonstration of such monolithic amplifier structure which contains an active fiber and a combiner based on 3C fibers. A single-stage amplifier is seeded by an EO Q-switched micro-laser and pumped by two high power fiber pigtailed 976-nm laser diodes via an in-house fabricated (2 + 1) × 1 pump signal combiner. The active fiber is based on a 3-m-long, 3C Yb-doped fiber (33 μm/250 μm core/cladding diameter with 0.06/0.46 NA). The amplifier demonstrates scaling up to 30W average power and 150 kW peak power in 0.3mJ, 2ns pulses. The beam profiles and beam qualities were characterized as its output power was varied up to 30W. The beam profile was maintained at a high beam quality of around M2=1.2. The spectral properties of the 3C fiber were also characterized as its output peak power was varied.

  16. New concept for a regenerative amplifier for passive optical networks

    Science.gov (United States)

    Tervonen, A.; Mattila, M.; Weiershausen, W.; von Lerber, T.; Parsons, E.; Chaouch, H.; Kueppers, F.; Honkanen, S.

    2011-01-01

    Photonic balancing - a scheme where logically opposite pulses derived from the two outputs of a delay-line demodulator for phase shift keyed (PSK) signals counter-propagate in the saturated regime of a semiconductor optical amplifier (SOA) - has been proven to enhance the receiver performance, e.g. in terms of decreased optical signal-to-noise-ratio (OSNR) requirements for a given target bit error ratio (BER). Here, we extend the photonic balancing scheme towards a new concept for a regenerative amplifier targeted at extending the reach and/or the number of subscribers in passive optical networks (PON) in order to support major operators' plans to reduce the number of central offices and access areas by approximately 90%. For a given target BER, we demonstrate experimentally (a) an 8-dB higher post-amplifier loss tolerance, (b) an extended feeder line length (75 km) combined with high splitting ratio (10 layers) for a preamplified version, and (c) high input power variation tolerance (> 30 dB burst-to-burst) in upstream direction as needed for highly asymmetric tree structures.

  17. Study on the ELDRS of bipolar linear operational amplifier

    International Nuclear Information System (INIS)

    Bipolar linear devices laboratory irradiation testing results are significantly different from the actual in flight exposure to the radiation. In this paper the total dose irradiation of operational amplifiers, and analysis upon the total dose response of these bipolar circuits under the different test conditions were investigated in the same experiment. Total dose tests of bipolar linear operational amplifiers show susceptible to dose rate, bias and room temperature annealing during exposure. The critical sensitive parameters of operational amplifier are input bias current, input offset current, input offset voltage, and open loop gain, which exhibits both bias and dose rate dependence. With calculating the change of each electrical parameter (Δpara) for each sample at 300 Gy radiation level, it has been found that ratio of the Δpara at low dose rate to the Δpara at high dose rate exceeds 2.46 times for any of the parameters. So these parts are considered to be ELDRS susceptible. After room temperature annealing, the main parameters have time dependence effect at low dose rate and without time dependent effect at high dose rate. (authors)

  18. On cuff imbalance and tripolar ENG amplifier configurations.

    Science.gov (United States)

    Triantis, Iasonas F; Demosthenous, Andreas; Donaldson, Nick

    2005-02-01

    Electroneurogram (ENG) recording techniques benefit from the use of tripolar cuffs because they assist in reducing interference from sources outside the cuff. However, in practice the performance of ENG amplifier configurations, such as the quasi-tripole and the true-tripole, has been widely reported to be degraded due to the departure of the tripolar cuff from ideal behavior. This paper establishes the presence of cuff imbalance and investigates its relationship to cuff asymmetry, cuff end-effects and interference source proximity. The paper also presents a comparison of the aforementioned amplifier configurations with a new alternative, termed the adaptive-tripole, developed to automatically compensate for cuff imbalance. The output signal-to-interference ratio of the three amplifier configurations were compared in vivo for two interference signals (stimulus artifact and M-wave) superimposed on compound action potentials. The experiments showed (for the first time) that the two interference signals result in different cuff imbalance values. Nevertheless, even with two distinct cuff imbalances present, the adaptive-tripole performed better than the other two systems in 61.9% of the trials. PMID:15709669

  19. Towards a THz Backward Wave Amplifier in European FP7 OPTHER Project

    DEFF Research Database (Denmark)

    Dispenza, Massimiliano; Cojocaru, C.-S.; De Rossi, Alfredo;

    2010-01-01

    Within the EC funded international project OPTHER (OPtically Driven TeraHertz AmplifiERs) a considerable technological effort is being undertaken, in terms of technological development, THz device design and integration. The ultimate goal is to develop a miniaturised THz amplifier based on vacuum...

  20. Investigation of switching frequency variations and EMI properties in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard; Andersen, Michael A. E.

    2009-01-01

    Class D audio amplifiers have gained significant influence in sound reproduction due to their high efficiency. One of the most commonly used control methods in these amplifiers is self-oscillation. A parameter of key interest in self-oscillating amplifiers is the switching frequency, which is kno...

  1. Locally Controlled Deeply Saturated Fiber Optic Parametric Amplifiers

    Science.gov (United States)

    Nissim, Ron Reuven

    A new class of highly efficient Optical Parametric Amplifiers (OPA) is explored in this dissertation, which have the potential to reduce the power requirement on the pump and enable new functionalities. This originates from the simple notion that figure of merit (FoM) of an OPA is proportional to the product of the pump power and amplifier's length and nonlinearity. Silica fibers have been developed for over five decades and offer unparalleled transparency. By merely extending the fiber, i.e. the amplifier's length, a high FoM amplifier can be formed while keeping the pump at a moderate, sub-Watt power level. Unfortunately, optical fibers are inherently non-uniform. Their core size fluctuates along the fiber on a nanometer scale which is on the order of the fiber's molecular constituents. It is currently established that the performance of a fiber-based OPA (FOPA) is dictated by its stochastic nature. In fact, given a moderate pump power level, the highly efficient OPA will be required to maintain a strict phase matching condition across hundreds of meters. Facing this challenge, this dissertation focuses on a locally-controlled, high FoM FOPA. A high FoM FOPA operates in the deeply saturated regime in which a weak signal saturates the amplifier and depletes the pump power, effectively generating an inverse response of the pump output power to the signal input power. Given FOPAs' inhomogeneous nature, the performance limit of deeply saturated FOPAs is studied. So far, FOPAs have been commonly treated as a uniform entity; however, this study discovers unique features of the system which originate from and are strongly influenced by the fiber's inhomogeneous nature. One major example is the non-reciprocal response of deeply saturated FOPAs. It was found that deeply saturated FOPAs perform very highly, as the pump can respond to a rapidly varying (sub-THz) weak (sub-muW) signal. This is a novel method which obtained orders of magnitude improvement over current

  2. Ultra-low noise miniaturized neural amplifier with hardware averaging

    Science.gov (United States)

    Dweiri, Yazan M.; Eggers, Thomas; McCallum, Grant; Durand, Dominique M.

    2015-08-01

    Objective. Peripheral nerves carry neural signals that could be used to control hybrid bionic systems. Cuff electrodes provide a robust and stable interface but the recorded signal amplitude is small (<3 μVrms 700 Hz-7 kHz), thereby requiring a baseline noise of less than 1 μVrms for a useful signal-to-noise ratio (SNR). Flat interface nerve electrode (FINE) contacts alone generate thermal noise of at least 0.5 μVrms therefore the amplifier should add as little noise as possible. Since mainstream neural amplifiers have a baseline noise of 2 μVrms or higher, novel designs are required. Approach. Here we apply the concept of hardware averaging to nerve recordings obtained with cuff electrodes. An optimization procedure is developed to minimize noise and power simultaneously. The novel design was based on existing neural amplifiers (Intan Technologies, LLC) and is validated with signals obtained from the FINE in chronic dog experiments. Main results. We showed that hardware averaging leads to a reduction in the total recording noise by a factor of 1/√N or less depending on the source resistance. Chronic recording of physiological activity with FINE using the presented design showed significant improvement on the recorded baseline noise with at least two parallel operation transconductance amplifiers leading to a 46.1% reduction at N = 8. The functionality of these recordings was quantified by the SNR improvement and shown to be significant for N = 3 or more. The present design was shown to be capable of generating <1.5 μVrms total recording baseline noise when connected to a FINE placed on the sciatic nerve of an awake animal. An algorithm was introduced to find the value of N that can minimize both the power consumption and the noise in order to design a miniaturized ultralow-noise neural amplifier. Significance. These results demonstrate the efficacy of hardware averaging on noise improvement for neural recording with cuff electrodes, and can accommodate the

  3. ACKA 500 WATT POWER AMPLIFIER FOR A 144 MHZ CHANNEL BASED ON A VHF PUSH-PULL POWER MOS TRANSISTOR

    OpenAIRE

    Agus Harjoko; Tri Wahyu Supardi

    2013-01-01

    In a wireless communication, a signal power amplifier is needed to carry signals over a long distance. Many signal amplifiers are made of tube as the amplifying component and as such they suffer low efficiency. This study presents results of the research on designing and implementing solid state 144MHz signal amplifier employing MOSFET BLF278 as the active component of the amplifier. The amplifier has an automatic activation switch, an input terminal, a 50 ohm impedance output terminal and a ...

  4. Narrow-band laser amplifier system for tunable UV light generation

    International Nuclear Information System (INIS)

    We developed a Ti:Sapphire narrow-band laser amplifier system for efficient third harmonic generation. The amplifier system was composed of a wavelength tunable narrow-band regenerative amplifier and a broadband multi-pass amplifier. With a pumping of ∼17 mJ by the second harmonics of a Nd:YLF laser, mode-locked seed pulses were amplified to ∼1.0 mJ at 1-kHz repetition. We obtained the third harmonic wave of ∼208-μJ pulse energy after the wavelength conversion by two β-BBO crystals. (author)

  5. To Design High CMRR, High Slew rate Instrumentation Amplifier using OTA and CDTA for Biomedical Application

    Directory of Open Access Journals (Sweden)

    Shruti Jain

    2013-09-01

    Full Text Available In today’s world operational amplifier is used in lot of application. The techniques for achieving high slew rate and high CMRR is by cascading the transistors. This paper focus is on understanding of Operational Trans conductance Amplifier (OTA and Current Differencing Trans conductance Amplifier (CDTA with its application as Instrumentation Amplifier (IA for Biomedical application. We have designed Instrumentation Amplifier using CDTA to obtain high common mode rejection ratio (CMRR, high slew rate in comparison with OTA using PSPICE software.

  6. A low power low noise amplifier for a 128 channel detector read-out integrated circuit

    International Nuclear Information System (INIS)

    This paper describes the design of a low power, low noise CMOS amplifier. The amplifier was designed using the folded cascade configuration and was implemented on a 3μm double polysilicon process. The amplifier is part of a 128 channel charge amplifier array chip for use in the read-out of radiation detectors with many channels. Aspects of the amplifier design such as band-width, pulse response, and noise are discussed and the effects of individual transistors are shown thereby relating circuit performance to process parameters; circuit test results are presented and radiation test results are included. (author)

  7. Modular 20 kW solid state RF amplifier for Indus-2 syncrotron radiation source

    International Nuclear Information System (INIS)

    This article presents the design and development of 505.8 MHz modular solid state Radio frequency (RF) amplifier capable of delivering 20 kW continuous RF power. It has been successfully commissioned for serving as the modern RF power source in Indus-2 synchrotron radiation source. For this amplifier, design procedure has been formulated for the solid state amplifier modules, radial combiner, divider, directional coupler and overall system architecture, with specifications suited to RF source for particle accelerator. This article describes underlying design principles and indigenous development of this amplifier, consisting of 400 W amplifier modules, 5 kW 16-port radial combiner/divider and directional couplers. Detail performance characterization of amplifier on component level as well as system level serves as useful data for higher power solid state amplifier designers. Simple design, indigenous technology, high efficiency and ease of fabrication, are the main features of this design.

  8. Modular 20 kW solid state RF amplifier for Indus-2 syncrotron radiation source

    Science.gov (United States)

    Jain, Akhilesh; Hannurkar, P. R.; Sharma, D. K.; Gupta, A. K.; Tiwari, A. K.; Lad, M.; Kumar, R.; Badapanda, M. K.; Gupta, P. D.

    2012-06-01

    This article presents the design and development of 505.8 MHz modular solid state Radio frequency (RF) amplifier capable of delivering 20 kW continuous RF power. It has been successfully commissioned for serving as the modern RF power source in Indus-2 synchrotron radiation source. For this amplifier, design procedure has been formulated for the solid state amplifier modules, radial combiner, divider, directional coupler and overall system architecture, with specifications suited to RF source for particle accelerator. This article describes underlying design principles and indigenous development of this amplifier, consisting of 400 W amplifier modules, 5 kW 16-port radial combiner/divider and directional couplers. Detail performance characterization of amplifier on component level as well as system level serves as useful data for higher power solid state amplifier designers. Simple design, indigenous technology, high efficiency and ease of fabrication, are the main features of this design.

  9. Amplified CWDM-based Next Generation Broadband Access Networks

    Science.gov (United States)

    Peiris, Sasanthi Chamarika

    The explosive growth of both fixed and mobile data-centric traffic along with the inevitable trend towards all-IP/Ethernet transport protocols and packet switched networks will ultimately lead to an all-packet-based converged fixed-mobile optical transport network from the core all the way out to the access network. To address the increasing capacity and speed requirements in the access networks, Wavelength-Division Multiplexed (WDM) and/or Coarse WDM (CWDM)-based Passive Optical Networks (PONs) are expected to emerge as the next-generation optical access infrastructures. However, due to several techno-economic hurdles, CWDM-PONs are still considered an expensive solution and have not yet made any significant inroads into the current access area. One of the key technology hurdles is the scalability of the CWDM-based PONs. Passive component optical insertion losses limit the reach of the network or the number of served optical network units (ONUs). In the recent years, optical amplified CWDM approaches have emerged and new designs of optical amplifiers have been proposed and demonstrated. The critical design parameter for these amplifiers is the very wide optical amplification bandwidth (e.g., 340 nm combined for both directions). The objective of this PhD dissertation work is first to engineer ring and tree-ring based PON architectures that can achieve longer unamplified PON reach and/or provide service to a greater number of ONUs and customers. Secondly is to develop new novel optical amplifier schemes to further address the scalability limitation of the CWDM-based PONs. Specifically, this work proposes and develops novel ultra wide-band hybrid Raman-Optical parametric amplifier (HROPA) schemes that operate over nearly the entire specified CWDM band to provide 340 nm bidirectional optical gain bandwidth over the amplified PON's downstream and upstream CWDM wavelength bands (about 170 nm in each direction). The performance of the proposed HROPA schemes is assessed

  10. A CHI wiggler ubitron amplifier experiment: Wiggler characterization

    Energy Technology Data Exchange (ETDEWEB)

    Taccetti, J.M.; Jackson, R.H.; Freund, H.P. [Naval Research Lab., Washington, DC (United States)] [and others

    1995-12-31

    A 35 GHz CHI (Coaxial Hybrid Iron) wiggler ubitron amplifier experiment is under construction at the Naval Research Laboratory. The CHI wiggler configuration has the potential of generating high wiggler magnetic fields at short periods with excellent beam focusing and transport properties. This makes it a desirable configuration for the generation of high power coherent radiation in relatively compact systems. The CHI wiggler consists of alternating rings of magnetic and non-magnetic materials concentric with a central rod of similar alternating design but shifted along the axis by half a period. Once inserted in a solenoidal magnetic field, the CHI structure deforms the axial field to create a radial field oscillating with the same periodicity as the rings. An annular electron beam is propagated through the coaxial gap where the oscillating radial field imparts an azimuthal wiggle motion. The principal goals of the experiment are to investigate the performance tradeoffs involved in the CHI configuration for high frequency amplifiers operating at low voltages with small wiggler periods. The nominal design parameters are a center frequency of 35 GHz, wiggler period of 0.75 cm, and beam voltage of approximately 150 kV. Calculations have shown an intrinsic (untapered) efficiency of {approximately} 7% when operating at 6.3 kG axial field (wiggler field, B{sub w}{approximately}1270 G). The calculated gain was 36 dB, saturating at a distance of 46 cm. These parameters yield an instantaneous amplifier bandwidth of {approximately} 25%. There appears to be room for further improvement in efficiency, a matter which will be scrutinized more closely in the final design. A prototype CHI wiggler is presently being fabricated for use in conjunction with an existing 30 kG superconducting solenoid. The performance properties of the prototype will be characterized and compared with linear and non-linear calculations.

  11. Automatic alignment of double optical paths in excimer laser amplifier

    Science.gov (United States)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  12. Amplify-and-forward relaying in wireless communications

    CERN Document Server

    Rodriguez, Leonardo Jimenez; Le-Ngoc, Tho

    2015-01-01

    This SpringerBrief explores the advantage of relaying techniques in addressing the increasing demand for high data rates and reliable services over the air. It demonstrates how to design cost-effective relay systems that provide high spectral efficiency and fully exploit the diversity of the relay channel. The brief covers advances in achievable rates, power allocation schemes, and error performance for half-duplex (HD) and full-duplex (FD) amplify-and-forward (AF) single-relay systems. The authors discuss the capacity and respective optimal power allocation for a wide range of HD protocols ov

  13. Propagation of squeezed radiation through amplifying or absorbing random media

    CERN Document Server

    Patra, M

    2000-01-01

    We analyse how nonclassical features of squeezed radiation (in particular the sub-Poissonian noise) are degraded when it is transmitted through an amplifying or absorbing medium with randomly located scattering centra. Both the cases of direct photodetection and of homodyne detection are considered. Explicit results are obtained for the dependence of the Fano factor (the ratio of the noise power and the mean current) on the degree of squeezing of the incident state, on the length and the mean free path of the medium, the temperature, and on the absorption or amplification rate.

  14. Optimization and Comparison for Different Raman Amplifier Configurations

    Institute of Scientific and Technical Information of China (English)

    刘雪明

    2004-01-01

    Gain spectra and corresponding optical signal-to-noise ratio (OSNR) for bi-directional multi-pump Raman amplifiers are optimized and compared. Numerical results exhibit that, for optimizing bi-directional multi-pump configurations, there are multiple global maxima for signal gain spectra, and different bi-directional pump cases have different gain ripple and noise performance. Bi-directionally pumping schemes with suitable pump spectra can obviously decrease the gain ripple and equalize the OSNR tilt in comparison with pure backward pumping schemes.

  15. Optimal linear detectors for nonorthogonal amplify-and-forward protocol

    KAUST Repository

    Ahmed, Qasim Zeeshan

    2013-06-01

    In this paper, we propose optimal linear detectors for non-orthogonal amplify-and-forward cooperative protocol when considering a single-relay scenario. Two types of detectors are proposed based on the principles of minimum mean square error (MMSE) and minimum bit error rate (MBER). The MMSE detector minimizes the mean square error, while the MBER minimizes the system bit error rate (BER). Both detectors exhibit excellent BER performance with relatively low complexity as compared to the maximal likelihood (ML) detector. The BER performance of both detectors is superior to the channel inversion, the maximal ratio combining, and the biased ML detectors. © 2013 IEEE.

  16. A low noise amplifier and its noise performances (Contract research)

    International Nuclear Information System (INIS)

    For development of two-dimensional position sensitive (2-D) neutron detectors with fast response and high spatial resolution, an ASIC with fast response and low noise performances is required. The MP8 and MP16, consisting of p-MOSFETs, with high gm and low noise have been proposed to develop the ASIC. In this paper a simple low noise amplifier (LNA) was designed and the noise power and the noise figure were analytically calculated. The results were also applied to LNAs using MP8 or MP16 configuration. The results showed that the MP8 and MP16 had enough performances for the ASIC. (author)

  17. Linear CMOS RF power amplifiers a complete design workflow

    CERN Document Server

    Ruiz, Hector Solar

    2013-01-01

    The work establishes the design flow for the optimization of linear CMOS power amplifiers from the first steps of the design to the final IC implementation and tests. The authors also focuses on design guidelines of the inductor's geometrical characteristics for power applications and covers their measurement and characterization. Additionally, a model is proposed which would facilitate designs in terms of transistor sizing, required inductor quality factors or minimum supply voltage. The model considers limitations that CMOS processes can impose on implementation. The book also provides diffe

  18. 2-.mu.m fiber amplified spontaneous emission (ASE) source

    Science.gov (United States)

    Jiang, Shibin (Inventor); Wu, Jianfeng (Inventor); Geng, Jihong (Inventor)

    2007-01-01

    A 2-.mu.m fiber Amplified Spontaneous Emission (ASE) source provides a wide emission bandwidth and improved spectral stability/purity for a given output power. The fiber ASE source is formed from a heavy metal oxide multicomponent glass selected from germanate, tellurite and bismuth oxides and doped with high concentrations, 0.5-15 wt. %, thulium oxides (Tm.sub.2O.sub.3) or 0.1-5 wt% holmium oxides (Ho.sub.2O.sub.3) or mixtures thereof. The high concentration of thulium dopants provide highly efficient pump absorption and high quantum efficiency. Co-doping of Tm and Ho can broaden the ASE spectrum.

  19. Electrical versus optical pumping of quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Bischoff, Svend; Mørk, Jesper

    2001-01-01

    The influence of the pumping mechanism for the dynamical properties of quantum dot amplifiers is investigated for 10, 40 and 160 GHz signals. A fast response is predicted in the case of optical pumping in the wetting layer (WL). The combination of fast relaxation and capture times and the presence...... of a reservoir of carriers in the WL opens up for the possibility of ultrafast gain recovery in QD devices. The strength of optical contra electrical pumping is that it reduces the bottleneck effect of a slow WL. Optical pumping thus allows significant improvement of the dynamical properties of QD...

  20. Biasing Circuits for Voltage Controlled GSM Power Amplifiers

    OpenAIRE

    van Bezooijen, André; Prikhodko, Dima; Van Roermund, A.H.M.

    2003-01-01

    In GSM phones voltage controlled power amplifiers are used to vary the output power.Inaccuracies in output power levels are predominantly caused by drift in PA gain over temperature and input power.In this paper we present biasing circuits that implement an inherently accurate gain control curve.These circuits are based on temperature stabilised V/I-converters and current mirrors.Applying current driven biasing of the first RF-stage reduces the input power dependency of the gain.Measurements ...

  1. Amplified-fragment length polymorphism fingerprinting of Mycoplasma species

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Friis, N.F.; Jensen, J.S.;

    1999-01-01

    Amplified-fragment length polymorphism (AFLP) is a whole-genome fingerprinting method based on selective amplification of restriction fragments. The potential of the method for the characterization of mycoplasmas was investigated in a total of 50 strains of human and animal origin, including......I restriction endonucleases and subsequent ligation of corresponding site-specific adapters. The amplification of AFLP templates with a single set of nonselective primers resulted in reproducible fingerprints of approximately 60 to 80 fragments in the size range of 50 to 500 bp, The method was able to...

  2. Infrared Few-Cycle Pulse Optical Parametric Amplifier

    OpenAIRE

    Ališauskas, Skirmantas

    2010-01-01

    Main objective of this thesis is to generate and amplify few cycle pulses in the infrared region. In this thesis, two approaches were introduced for few cycle pulse parametric amplification at 800 nm and 1.5 μm. First approach is dedicated for prospects for increasing average power of OPCPA via multi-beam pumping; the second approach is dedicated for generation of carrier-envelope-phase (CEP) stable high energy (up to tens of millijoules) few-cycle pulses at 1.5 μm. An experimental investi...

  3. Analysis and implementation of an improved recycling folded cascode amplifier

    Institute of Scientific and Technical Information of China (English)

    李一雷; 韩科峰; 闫娜; 谈熙; 闵昊

    2012-01-01

    A generally improved recycling folded cascode (IRFC) is analyzed and implemented.Analysis and comparisons among the IRFC,the original recycling folded cascode (RFC) and the conventional folded cascode (FC) are made,and it is shown that with the flexible structure of IRFC,significant enhancement in transconductance,slew rate and noise can be achieved.Prototype amplifiers were fabricated in 0.13 μm technology.Measurement shows that IRFC has 3 × enhancement in gain-bandwidth and slew rate over conventional FC,and the enhancement is 1.5× when compared with the RFC.

  4. High Power Wideband Class-E Power Amplifier

    OpenAIRE

    Ortega González, Francisco Javier

    2010-01-01

    This letter shows a high-power, high-efficiency, wideband Class-E RF power amplifier designed upon the load admittance synthesis concept and built using an uncomplicated low-loss load network with a low loss wideband admittance transformer as the main component. It uses a power Silicon LDMOS transistor to provide up to 145 W at 28 V peak power, up to 86% drain efficiency over 35% fractional bandwidth (from 85 to 120 MHz) and 15.6 dB gain at peak power without any adjustments. These are clear ...

  5. Femtosecond Optical Parametric Amplifier for Petawatt Nd:Glass Lasers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Min; QIAN Lie-Jia; YUAN Peng; LUO Hang; ZHU He-Yuan; ZHU Qi-Hua; WEI Xiao-Feng; FAN Dian-Yuan

    2006-01-01

    @@ We study a femtosecond Ti:sapphire laser pumped optical parametric amplifier (OPA) at 1053nm. The OPA generates stable signal pulses with duration smaller than 100 fs, wavelength drift smaller than 0.5nm, and pulse-to-pulse fluctuation of about ±4%, by employing an external seeder. In a terawatt laser pumped large-aperture LiNbO3 OPA, pulse energy at signal has been scaled up to 4mJ. This m J-class femtosecond OPA at 1053nm presents a feasible alternative to optical parametric chirped-pulse amplification, and is ready to be applied to petawatt lasers.

  6. Mode-Locking in a Free-Electron Laser Amplifier

    OpenAIRE

    Thompson, N. R.; McNeil, B.W.J.

    2008-01-01

    A technique is proposed to generate attosecond pulse trains of radiation from a Free-Electron Laser amplifier. The optics-free technique synthesises a comb of longitudinal modes by applying a series of spatio-temporal shifts between the co-propagating radiation and electron bunch in the FEL. The modes may be phase-locked by modulating the electron beam energy at the mode spacing frequency. Three-dimensional simulations demonstrate the generation of a train of 400as pulses at giga-watt power l...

  7. Desigin of Synthetic Elements with Transimpedance Operational Amplifiers

    Directory of Open Access Journals (Sweden)

    Milan Murina

    2006-01-01

    Full Text Available One way how to design active filters for wider frequency band is application of transimpedance operational amplifiers (TOAs based on current mode. For this aim the TOAs exhibit the most suitable properties: large bandwidth, highslew rate, good linearity, high gain, low offset voltage, etc. The paper shows their possibilities for creation of synthetic elements. There will be discussed the relevant problems of synthetic elements above their properties with application of real TOAs. Theoretical relations of synthetic elements calculation will be derived on the base of real TOAs equivalent circuit and possibility of the synthetic elements to design and synthesis of low-sensitivity ARC filters will be shown.

  8. Gain recovery dynamics and limitations in quantum dot amplifiers

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Bischoff, Svend; Magnúsdóttir, Ingibjörg; Mørk, Jesper; Borri, Paola

    Summary form only given. While ultra-low threshold current densities have been achieved in quantum dot (QD) lasers, the predicted potential for high-speed modulation has not yet been realized despite the high differential gain. Furthermore, recent single pulse experiments demonstrated very fast...... gain recovery in a quantum dot amplifier, and it is thus not yet clear what the limiting processes for the device response are. We present the results of a comprehensive theoretical model, which agrees well with the experimental results, and indicates the importance of slow recovery of higher energy...

  9. X-ray laser '' oscillator-amplifier'' experiments

    International Nuclear Information System (INIS)

    We present results from experiments directed toward increasing the degree of transverse coherence in x-ray laser beams. We have concentrated on the neon-like yttrium (Z=39) collisionally-pumped x-ray laser as the test system for these studies because of its unique combination of brightness, monochromaticity, and high-reflectivity optics availability. Attempts at improving laser performance using proximate feedback optics failed. Modest success has been found to date in ''double foil'' experiments, involving two x-ray lasers spatially separated by 29 cm and shot sequentially in an ''oscillator-amplifier'' configuration

  10. Numerical Modelling of Spontaneous Emission in Optical Parametric Amplifiers

    DEFF Research Database (Denmark)

    Friis, Søren Michael Mørk; Andersen, Ulrik Lund; Rottwitt, Karsten

    2013-01-01

    . However, it is well accepted that one contribution to the noise performance originates from vacuum fluctuations. In this work we show a novel approach to predict the spontaneous radiation from a parametric amplifier. In the approach the propagating fields are treated as a sum of a classical mean field......Fiber optical parametric processes offer a wide range of applications including phase sensitive as well as phase insensitive amplification, wavelength conversion and signal regeneration. One of the difficult challenges is any of these applications is to predict their associated noise performance...

  11. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

    OpenAIRE

    Jieun Lee; Jaeman Jang; Bongsik Choi; Jinsu Yoon; Jee-Yeon Kim; Yang-Kyu Choi; Dong Myong Kim; Dae Hwan Kim; Sung-Jin Choi

    2015-01-01

    This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response of field-effect-transistor (FET)-based biosensors. The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential advantage of high density and low noise performance. The biosensor shows a current response of 5.74 decades per pH for pH detection, which is 2.5 × 105 times larger than that of a single SiNW sensor. I...

  12. Sub-100-fs Yb:CALGO nonlinear regenerative amplifier

    OpenAIRE

    pouysegur, julien; Delaigue, Martin; Zaouter, Yoann; Hönninger, Clemens; Mottay, Eric; Jaffrès, Anaël; Loiseau, Pascal; Viana, Bruno; Georges, Patrick; Druon, Frédéric

    2013-01-01

    We report on the first diode-pumped Yb∶CaGdAlO 4 regenerative amplifier in the sub-100-fs regime. It generates pulses at a central wavelength of 1047 nm with up to 24 μJ energy (after compression) at a repetition rate of 50 kHz. The measured pulse duration is 97 fs, with a spectral bandwidth of 19 nm. We describe in detail how non-linear effects are optimally used to compensate gain narrowing in order to overcome the 100 fs barrier. Many industrial applications, such as athermal microma-chini...

  13. The Effect of System and Amplifier Parameters on the Performance of Average Soliton Transmission System Using PSA as In-Line Amplifier

    Institute of Scientific and Technical Information of China (English)

    LIN Hong-rong; YANG Ai-xia; QIAN Sheng; LI Yue-hui

    2004-01-01

    In this paper, the effect of system and amplifier parameters on the performance of soliton transmission system using Phase Sensitive Amplifier (PSA) as in-line amplifier has been researched theoretically by computer simulation.Since in PSA soliton system the performance of average soliton regime is much better than that of dynamic soliton regime,in our simulation we only considered average soliton regime. Our simulation results show that although using PSA as inline amplifiers in soliton system can not only overcome Gordon-Haus restriction but also suppress solitons interaction,lengthen soliton stable transmission distance significantly, the system and amplifier parameters have to be chosen carefully in order to get a better system performance.

  14. Autofluorography with an X-Ray Image Amplifier

    International Nuclear Information System (INIS)

    The visualization of organs containing radioactive isotopes emitting X- or gamma-ray photons with energies between 20 and about 100 keV can be achieved by converting the radiation emerging from the organ into light by means of an X-ray image amplifier of conventional design. The apparatus designed for this purpose consists of the following elements: (1) A collimator, the specifications of which are determined by the resolution and by the operating distance desired. (2) An electrostatic focusing X-ray image amplifier, which converts the collimated X- or gamma-ray photons into an optical image of high brightness. (3) A large aperture lens system which projects the image into: (4) A ''Polaroid'' camera loaded with fast (10 000 ASA), high-contrast film. The performance of this apparatus for low-energy photons is superior to that of conventional scintiscanners. The usefulness of this apparatus for the visualization of brain tumours and kidneys and the thyroid gland is discussed. (author)

  15. `Soft' amplifier circuits based on field-effect ionic transistors

    Science.gov (United States)

    Boon, Niels; Olvera de La Cruz, Monica

    Soft materials can be used as building blocks of electronic devices with extraordinary properties. We demonstrate that an ionic analogue of the semiconductor field-effect transistor (FET) could be used for voltage and current amplifiers. Our theoretical model incorporates readily-available soft materials, such as conductive porous membranes and polymer electrolytes to represent a current-gating device that can be integrated in electronic circuits. By means of Nernst-Planck numerical simulations as well as an analytical approach towards expressions that describe steady-state currents, we find that the behavior in response to various input voltages can be categorized into ohmic, sub-threshold, and active modes. This is fully analogous to what is known for semiconductor FETs. Pivotal FET properties such as threshold voltage and transconductance must be related to half-cell redox potentials as well as polyelectrolyte and gate material properties. We further extend the analogy with semiconductor FETs through numerical simulations of elementary amplifier circuits in which we successfully substitute the semiconductor transistor by an ionic FET.

  16. Mismatch Calibration in LINC Power Amplifiers Using Modified Gradient Algorithm

    Directory of Open Access Journals (Sweden)

    Hosein Miar-Naimi

    2013-09-01

    Full Text Available One of the power amplifiers linearization technique is linear amplification with nonlinear components (LINC.The effects of phase and gain imbalances between two signal branches in LINC transmitters have been analyzed in this paper. Then a feedback path has been added to compensate this mismatches, using two complex gain in each path.This complex gains are controlled in a way to calibrate any gain and phase mismatches between two path using Modified Gradient Algorithm (MGA adaptively. The main advantages of this algorithm over other algorithms are zero residual error and fast convergence time. In the proposedarchitecture power amplifiers in each path are modeled as a complex gain which its phase and amplitude depend on input signal level. Many simulations have been performed to validate the proposed self calibrating LINC transmitter. Simulation results have confirmed the analyticalpredictions. According to simulation results the proposed structure has around 40 dB/Hz improvement in the first adjacent channel of the output signal spectrum.

  17. Regenerative FEL amplifier at the TESLA test facility at DESY

    International Nuclear Information System (INIS)

    This paper presents a conceptual design of a regenerative FEL amplifier (RAFEL) as an extension of the single-pass free electron laser project at the TESLA test facility (TTF) at DESY. The proposed scheme requires the additional installation of only two optical components for a narrow-band feedback system and is fully compatible with the present design and the infrastructure developed for the TTF FEL project. It would allow to construct a tunable VUV laser with a minimum wavelength around 60 nm, a pulse duration of about 1 ps, a peak power of about 300 MW and an average power of about 25 W. The output radiation of the regenerative FEL amplifier would possess all the features which are usually associated with laser radiation: full transverse and longitudinal coherence and shot-to-shot stability of the output power. The degeneracy parameter of the output radiation would be about 1014 and thus have the same order of magnitude as that of a quantum laser operating in the visible

  18. Thin-disk laser multi-pass amplifier

    CERN Document Server

    Schuhmann, K; Graf, T; Hänsch, T W; Kirch, K; Kottmann, F; Pohl, R; Taqqu, D; Voß, A; Weichelt, B; Antognini, A

    2015-01-01

    In the context of the Lamb shift measurement in muonic helium we developed a thin-disk laser composed of a Q-switched oscillator and a multi-pass amplifier delivering pulses of 150 mJ at a pulse duration of 100 ns. Its peculiar requirements are stochastic trigger and short delay time (< 500 ns) between trigger and optical output. The concept of the thin-disk laser allows for energy and power scaling with high efficiency. However the single pass gain is small (about 1.2). Hence a multi-pass scheme with precise mode matching for large beam waists (w = 2 mm) is required. Instead of using the standard 4f design, we have developed a multi-pass amplifier with a beam propagation insensitive to thermal lens effects and misalignments. The beam propagation is equivalent to multiple roundtrips in an optically stable resonator. To support the propagation we used an array of 2 x 8 individually adjustable plane mirrors. Astigmatism has been minimized by a compact mirror placement. Precise alignment of the kinematic arra...

  19. DESIGN OF SEQUENTIALLY FED BALANCED AMPLIFYING ANTENNA FOR CIRCULAR POLARIZATION

    Directory of Open Access Journals (Sweden)

    S. K. Behera

    2010-12-01

    Full Text Available This paper presents a sequentially fed balanced amplifying antenna that exhibits circularly polarized radiation. The inherent benefits of good isolation between input and output ports as well as improved matching capabilities of balanced amplifiers provide overall system gain of 8 dBi at frequency 2.36GHz. The planar arrangement of the patch antenna elements are considered to form an array. The phase of the feeding in the array increases progressively from 00 to 2700.Each element in the array is linearly polarized. Here four elements were considered and 2arranged at the four corners of a square domain. This arrangement shows that each antenna sees its adjacent ones to be radiating from an edge orthogonal to its edge of radiation. Circular polarization is achieved due to this sequential feeding. This array is designed with operating frequency 2.4 GHz. A good axial ratio of 2.4 is obtained at 2.37 GHz frequency. The noise figure is considerably reduced and which is around -19dB.

  20. Regime for a Self-ionizing Raman Laser Amplifier

    International Nuclear Information System (INIS)

    Backward Raman amplification and compression at high power might occur if a long pumping laser pulse is passed through a plasma to interact resonantly with a counter-propagating short seed pulse [V.M. Malkin, et al., Phys. Rev. Lett. 82 (1999) 4448-4451]. One critical issue, however, is that the pump may be unacceptably depleted due to spontaneous Raman backscatter from intrinsic fluctuations in the amplifying plasma medium prior to its useful interaction with the seed. Premature backscatter may be avoided, however, by employing a gaseous medium with pump intensities too low to ionize the medium, and using the intense seed to produce the plasma by rapid photoionization as it is being amplified [V.M. Malkin, et al., Phys. Plasmas (2001)]. In addition to allowing that only rather low power pumps be used, photoionization introduces a damping of the short pulse which must be overcome by the Raman growth rate for net amplification to occur. The parameter space of gas densities, laser wavelengths, and laser intensities is surveyed to identify favorable regimes for this effect. Output laser intensities of 10(superscript ''17'') W/cm(superscript ''2'') for 0.5 mm radiation are found to be feasible for such a scheme using a pump of 10(superscript ''13'') W/cm(superscript ''2'') and an initial seed of 5 x 10(superscript ''14'') W/cm(superscript ''2'') over an amplification length of 5.6 cm in hydrogen gas

  1. Regime for a self-ionizing Raman laser amplifier

    International Nuclear Information System (INIS)

    Backward Raman amplification and compression at high power might occur if a long pumping laser pulse is passed through a plasma to interact resonantly with a counter-propagating short seed pulse [V. M. Malkin et al., Phys. Rev. Lett. 82, 4448-4451 (1999)]. One critical issue, however, is that the pump may be unacceptably depleted due to spontaneous Raman backscatter from intrinsic fluctuations in the amplifying plasma medium prior to its useful interaction with the seed. Premature backscatter may be avoided, however, by employing a gaseous medium with pump intensities too low to ionize the medium and using the intense seed to produce the plasma by rapid photoionization as it is being amplified [V. M. Malkin et al., Phys. Plasmas 8, 4698-4699 (2001)]. In addition to allowing that only rather low power pumps be used, photoionization introduces a damping of the short pulse which must be overcome by the Raman growth rate for net amplification to occur. The parameter space of gas densities, laser wavelengths, and laser intensities is surveyed to identify favorable regimes for this effect. Output laser intensities of 2x1017 W/cm2 for 0.5 μm radiation are found to be feasible for such a scheme using a pump of 1x1013 W/cm2 and an initial seed of 5x1014 W/cm2 over an amplification length of 5.6 cm in hydrogen gas

  2. Spheromak reactor with poloidal flux-amplifying transformer

    Science.gov (United States)

    Furth, Harold P.; Janos, Alan C.; Uyama, Tadao; Yamada, Masaaki

    1987-01-01

    An inductive transformer in the form of a solenoidal coils aligned along the major axis of a flux core induces poloidal flux along the flux core's axis. The current in the solenoidal coil is then reversed resulting in a poloidal flux swing and the conversion of a portion of the poloidal flux to a toroidal flux in generating a spheromak plasma wherein equilibrium approaches a force-free, minimum Taylor state during plasma formation, independent of the initial conditions or details of the formation. The spheromak plasma is sustained with the Taylor state maintained by oscillating the currents in the poloidal and toroidal field coils within the plasma-forming flux core. The poloidal flux transformer may be used either as an amplifier stage in a moving plasma reactor scenario for initial production of a spheromak plasma or as a method for sustaining a stationary plasma and further heating it. The solenoidal coil embodiment of the poloidal flux transformer can alternately be used in combination with a center conductive cylinder aligned along the length and outside of the solenoidal coil. This poloidal flux-amplifying inductive transformer approach allows for a relaxation of demanding current carrying requirements on the spheromak reactor's flux core, reduces plasma contamination arising from high voltage electrode discharge, and improves the efficiency of poloidal flux injection.

  3. Amplified effect of surface charge on cell adhesion by nanostructures

    Science.gov (United States)

    Xu, Li-Ping; Meng, Jingxin; Zhang, Shuaitao; Ma, Xinlei; Wang, Shutao

    2016-06-01

    Nano-biointerfaces with varied surface charge can be readily fabricated by integrating a template-based process with maleimide-thiol coupling chemistry. Significantly, nanostructures are employed for amplifying the effect of surface charge on cell adhesion, as revealed by the cell-adhesion performance, cell morphology and corresponding cytoskeletal organization. This study may provide a promising strategy for developing new biomedical materials with tailored cell adhesion for tissue implantation and regeneration.Nano-biointerfaces with varied surface charge can be readily fabricated by integrating a template-based process with maleimide-thiol coupling chemistry. Significantly, nanostructures are employed for amplifying the effect of surface charge on cell adhesion, as revealed by the cell-adhesion performance, cell morphology and corresponding cytoskeletal organization. This study may provide a promising strategy for developing new biomedical materials with tailored cell adhesion for tissue implantation and regeneration. Electronic supplementary information (ESI) available: Experimental details, SEM, KFM AFM, chemical modification and characterization. See DOI: 10.1039/c6nr00649c

  4. Efficient Slew-Rate Enhanced Operational Transconductance Amplifier

    Institute of Scientific and Technical Information of China (English)

    Xiao-Peng Wan; Fei-Xiang Zhang; Shao-Wei Zhen; Ya-Juan He; Ping Luo

    2015-01-01

    Abstract⎯Today, along with the prevalent use of portable equipment, wireless, and other battery powered systems, the demand for amplifiers with a high gain-bandwidth product (GBW), slew rate (SR), and at the same time very low static power dissipation is growing. In this work, an operational transconductance amplifier (OTA) with an enhanced SR is proposed. By inserting a sensing resistor in the input port of the current mirror in the OTA, the voltage drop across the resistor is converted into an output current containing a term in proportion to the square of the voltage, and then the SR of the proposed OTA is significantly enhanced and the current dissipation can be reduced. The proposed OTA is designed and simulated with a 0.5μm complementary metal oxide semiconductor (CMOS) process. The simulation results show that the SR is 4.54 V/μs, increased by 8.25 times than that of the conventional design, while the current dissipation is only 87.3%.

  5. Power Amplifier Linearization Techniques for 3rd Generation Handsets

    DEFF Research Database (Denmark)

    Nielsen, Troels Studsgaard

    Linearization is a systematic method for reducing an amplifier’s distortion. By distortion reduction, the linearizer allows the amplifier to produce more output power and thereby to operate at a higher level of efficiency for a given level of distortion. There exist a number of different Power...... put on the study, design, and implementation of a 5th order polynomial workfunction predistorter. To facilitate a realistic predistorter system study, an accurate PA behavioral model is developed from pulsed large signal S-parameters measurements of a real 3G-PP W-CDMA device. At the nominal 0d...... blocks: An RF variable gain amplifier, an envelope detector, and a polynomial workfunction. In a 3G-PP W-CDMA application with a real PA device, the linearizer is able to improve PA adjacent channel power ratio by 9.3dB and 1st alternate channel power ratio by 5.3dB. This immediate reduction in spectral...

  6. Initial tests of an 11.4 GHz magnicon amplifier

    International Nuclear Information System (INIS)

    The magnicon, a scanning beam microwave amplifier related to the gyrocon, is a possible replacement for klystron amplifiers in future high-gradient linear accelerators. The magnicon circuit consists of a multicavity deflection system followed by an output cavity. The purpose of the deflection system is to spin up the electron beam phase-coherently to high transverse momentum. In order to do this, the deflection cavities employ rotating TM11 modes, producing a gyrating electron beam whose centroid rotates about the cavity axis in synchronism with the advance in phase of the rf modes. The output cavity employs a cyclotron resonant mechanism to extract principally the transverse beam momentum. It employs an rf mode that rotates synchronously with the deflection cavity modes, and with the entry point of the electron beam into the output cavity, making possible a highly efficient interaction. The NRL magnicon uses a 100--200 A, 500 keV beam produced by a cold-cathode diode on the NRL Long-Pulse Accelerator Facility. The first cavity is externally driven at 5.7 GHz, while the output cavity is designed to produce megawatts of power at 11.4 GHz in the TM210 mode. In this paper, the authors present a progress report on the NRL magnicon experiment. They will discuss the procedure used to cold test and calibrate the magnicon circuit, and present initial results from experimental operations

  7. An Electronically Tunable Transconductance Amplifier for Use in Auditory Prostheses

    Directory of Open Access Journals (Sweden)

    FARAGO, P.

    2015-11-01

    Full Text Available Low-voltage and low-power trends in analog electronics enable novel features in modern bio-medical devices, such as extensive portability, autonomy and even battery-less operation. One specific example is the cochlear implant (CI, which emulates the physiology of hearing to produce auditory sensations via neural stimulation. Besides low-voltage and low-power operation, a key feature in modern CIs is wide-range programmability of the speech processing parameters. This paper proposes an operational transconductance amplifier (OTA for use in CIs, with wide-range electronic tuning of the transconductance value. The proposed OTA is developed around a cascade of two transconductor stages, making the transconductance dependent on the bias current ratio. A combination of linearization techniques: bulk input, parallel differential pairs and feedback, is used to achieve sufficient linear range for CI speech processing. Wide-range parameter tuning of the speech processing sections is illustrated on a variable gain amplifier, a bandpass Tow-Thomas biquad and an envelope detector. Finally, the complete CI speech processing chain is illustrated. The proposed OTA and its employment in CI analog speech processing are validated on a 350 nm CMOS process.

  8. Sensitive pre-amplifier to load for Pin diodes

    International Nuclear Information System (INIS)

    The electronic instrumentation is indispensable for the measurement and characterization of the radiation. By means of this essential characteristics of the radiation are determined, as activity and their energy components. The nuclear instrumentation is based on the technical characteristics of the radiation detectors and the electronic devices associates (amplifiers, ana logical and digital converters, multichannel analyzers, etc.) The radiation detectors are very important instruments in fields as the nuclear physics, medicine, radiological protection, industry and in other fields, since they are the only method to capture the radiation and to be able to quantify it in precise form. To detect radiation diverse detector types are used, as the semiconductor type, inside them are the photodiodes type Pin. In this work the results that were obtained of the design, simulation, construction and tests of a preamplifier that was designed starting from a photodiode type Pin are presented. The system was designed and simulated with a program for electronic circuits, in this were carried out many tests being obtained a compact design and achieving the best necessary characteristics for its optimization. With the results of the simulation phase the electronics phase was built, which was couples to a spectroscopic amplifier and a multichannel analyzer. The total of the system was evaluated analyzing its performance before a triple source of alphas. Of the tests phase we find that the system allows obtaining, in a multichannel analyzer, the pulses height spectrum, with a good resolution and with this was calibrated the multichannel analyzer

  9. Towards a generic operational amplifier with dynamic reconfiguration capability

    Directory of Open Access Journals (Sweden)

    S. K. Lakshmanan

    2006-01-01

    Full Text Available Analog and analog-digital mixed signal electronics needed for sensor systems are indispensable components which tend to drifts from the normal phase of operation due to the impact of manufacturing conditions and environmental influences like etching, aging etc. Precise design methodology, trimming / calibration are essential to restore functionality of the system. Recent block level granular approaches using Field Programmable Analog Array and the more recent approaches from evolutionary electronics providing transistor level granularity using Field Programmable Transistor Arrays offers considerable extensions. In our work, we started on a new medium granular level approach called Field Programmable medium-granular Mixed-signal Array (FPMA providing basic building blocks of heterogeneous array of active and passive devices to configure established circuit structures which are adaptive, biologically inspired and dynamically re-configurable. Our design objective is to create components of clear compatibility to that of the industrial standards having predictable behavior along with the incorporation of existing design knowledge. The cells can be used in as a single instance or multiple instances. Further, we will focus on a generic dynamic reconfigurable amplifier cell with flexible topology and dimension called Generic Operational Amplifier (GOPA. The incentive of our work comes from recent development in the field of measurement and instrumentation. The digital programming of analog devices is carried out using range of algorithms from simple to evolutionary. Physical realization of the basic cells is carried out in 0.35 μm CMOS technology.

  10. Effect of amplified spontaneous emission and parasitic oscillations on the performance of cryogenically-cooled slab amplifiers

    Czech Academy of Sciences Publication Activity Database

    Sawicka, Magdalena; Divoký, Martin; Lucianetti, Antonio; Mocek, Tomáš

    2013-01-01

    Roč. 31, č. 4 (2013), s. 553-560. ISSN 0263-0346 R&D Projects: GA MŠk ED2.1.00/01.0027; GA MŠk EE2.3.20.0143 Grant ostatní: HILASE(XE) CZ.1.05/2.1.00/01.0027; OP VK 6(XE) CZ.1.07/2.3.00/20.0143 Institutional support: RVO:68378271 Keywords : amplified spontaneous emission * cryogenic cooling * parasitic oscillations * slab lasers * Yb: YAG , Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.701, year: 2013

  11. Analysis of a wide-band amplifier realized on the base of microcircuits

    International Nuclear Information System (INIS)

    Discussed is an approach to the design of a wide-band amplifier with stable characteristics and realized on the base of microcircuits. The scheme of the concrete amplifier operating under the matching conditions with 75-ohmic cable at the amplifier input and output is analyzed. The amplifier is developed on the base of microcircuits and involved into a mehallic-glass case. The finefilm resistors are used in the scheme; the 2T31064-2 transistor is used on the first stage, the other stages are performed on the base of 2T354B transistors. The amplifier operating gain equals to 20-0.5 db, the upper boundary frequency is >=250 MHz, the lower boundary frequency is =250 MV, the voltage supply is equal to 6.3 V and its energy input is < 200 MW. The amplifier retains its properties in the temperature range from - 60 to + 70 deg C

  12. Microwave amplifier and active circuit design using the real frequency technique

    CERN Document Server

    Jarry, Pierre

    2016-01-01

    This book focuses on the authors' Real Frequency Technique (RFT) and its application to a wide variety of multi-stage microwave amplifiers and active filters, and passive equalizers for radar pulse shaping and antenna return loss applications. The first two chapters review the fundamentals of microwave amplifier design and provide a description of the RFT. Each subsequent chapter introduces a new type of amplifier or circuit design, reviews its design problems, and explains how the RFT can be adapted to solve these problems. The authors take a practical approach by summarizing the design steps and giving numerous examples of amplifier realizations and measured responses. Provides a complete description of the RFT as it is first used to design multistage lumped amplifiers using a progressive optimization of the equalizers, leading to a small umber of parameters to optimize simultaneously Presents modifications to the RFT to design trans-impedance microwave amplifiers that are used for photodiodes acti...

  13. Performance Simulation and Optimization of Er3+/Pr3+ Doped Fiber Amplifiers by Optisystem

    Directory of Open Access Journals (Sweden)

    Jiuru Yang

    2013-01-01

    Full Text Available The joint amplifying system based Erbium Doped Fiber Amplifier (EDFA and Praseodymium Doped Fiber Amplifier (PDFA has been regarded as one of the promising technologies in optical core networks. However, due to the complex structure and high cost, it is unpractical to optimize the performance for these two amplifiers by experiments. In this study, to overcome this problem and enhance the output performance, the operation processes of EDFA and PDFA are modeled by adopting the Optisystem software. Then, according to the spectrum characteristics of the amplifying systems obtained, the analysis in detail is conducted respectively. Consequently, based on the quantitative results in terms of gain, flatness and noises, the optimal parameters with the respect of pumping power and the length of EDF/PDF are determinate and the output performance of these two amplifying system is also improved obviously.

  14. Propagation of a partially coherent laser beam through the inhomogeneous medium of an optical amplifier

    International Nuclear Information System (INIS)

    The propagation of a partially coherent laser beam through a single-pass optical amplifier is considered in the complex geometric optics approximation. A system of equation is obtained which describes changes in the complex amplitude and complex phase of the coherence function of the laser beam in the inhomogeneous medium of the amplifier. The power and intensity of the amplified radiation are analysed as functions of the coherence radius of the laser beam and the optical strength of a gas lens produced in the amplifier medium due to the spatial inhomogeneity of the energy deposition. It is found that the effect of the gas lens and partial coherence of radiation on the gain depends on the relation between the input beam radius and the amplifier aperture. It is shown that the energy gain increases with increasing the lens strength and improving the beam coherence, whereas the opposite behaviour is inherent in 'narrow' beams. (optical amplifiers)

  15. Influence on measuring ionization chamber's time response speed with charge integration amplifying circuit

    International Nuclear Information System (INIS)

    The time response speed of measuring amplifier directly influences the research on ionization chamber's time response speed. The reasons why the measuring circuit was designed with charge integration amplifier were presented. The mechanism of emerging stepped current signal of ionization chamber unit irradiated by a stable radiation source was analyzed. The method of studying amplifier time response by measuring the changing process of current signal was proposed. The relationship of the amplifier's time response speed with the detector unit interelectrode capacitance, the amplifier's input protecting resistance and its feedback integral capacitance was studied through experiment. It is concluded that the amplifier's time response speed is concerned with the constant time of ionization chamber unit interelectrode capacitance and protecting resistance. And it is not concerned with the feedback integral capacitance. It provides theoretical guidance on designing ionization chamber and measuring circuit. (authors)

  16. A near-quantum-limited Josephson traveling-wave parametric amplifier.

    Science.gov (United States)

    Macklin, C; O'Brien, K; Hover, D; Schwartz, M E; Bolkhovsky, V; Zhang, X; Oliver, W D; Siddiqi, I

    2015-10-16

    Detecting single-photon level signals—carriers of both classical and quantum information—is particularly challenging for low-energy microwave frequency excitations. Here we introduce a superconducting amplifier based on a Josephson junction transmission line. Unlike current standing-wave parametric amplifiers, this traveling wave architecture robustly achieves high gain over a bandwidth of several gigahertz with sufficient dynamic range to read out 20 superconducting qubits. To achieve this performance, we introduce a subwavelength resonant phase-matching technique that enables the creation of nonlinear microwave devices with unique dispersion relations. We benchmark the amplifier with weak measurements, obtaining a high quantum efficiency of 75% (70% including noise added by amplifiers following the Josephson amplifier). With a flexible design based on compact lumped elements, this Josephson amplifier has broad applicability to microwave metrology and quantum optics. PMID:26338795

  17. The generation of amplified spontaneous emission in high‐power CPA laser systems

    OpenAIRE

    Keppler, Sebastian; Sävert, Alexander; Körner, Jörg; Hornung, Marco; Liebetrau, Hartmut; Hein, Joachim; Kaluza, Malte Christoph

    2015-01-01

    Abstract An analytical model is presented describing the temporal intensity contrast determined by amplified spontaneous emission in high‐intensity laser systems which are based on the principle of chirped pulse amplification. The model describes both the generation and the amplification of the amplified spontaneous emission for each type of laser amplifier. This model is applied to different solid state laser materials which can support the amplification of pulse durations ≤ 350 fs . The res...

  18. L-band AlGaN/GaN Power Amplifier with Protection Against Load Mismatch

    OpenAIRE

    Heijningen , M. van; Bent, G. van der; Houwen, E.H. van de; A Chowdhary; Vliet, F.E. van

    2013-01-01

    Solid-state power amplifiers need protection at the output to handle high reflections due to mismatch. Normally this is implemented by using a ferrite-based isolator. These are however large and bulky components. This paper presents a Gallium-Nitride power amplifier module with automatic protection against large reflections based on fold-back protection, by sensing the reflected power. Measurements have been performed on a 100 W L-band power amplifier module at full reflection (short at the o...

  19. High power amplifier pre-distorter based on neural-fuzzy systems for OFDM signals

    OpenAIRE

    Gil-Jiménez, Víctor P.; jabrane, younes; García-Armada, Ana; Ait Es Said, Brahim; Ait Ouahman, Abdellah

    2011-01-01

    In this paper, a novel High Power Amplifier (HPA) pre-distorter based on Adaptive Networks - Fuzzy Inference Systems (ANFIS) for Orthogonal Frequency Division Multiplexing (OFDM) signals is proposed and analyzed. Models of Traveling Wave Tube Amplifiers (TWTA) and Solid State Power Amplifiers (SSPA), both memoryless and with memory, have been used for evaluation of the proposed technique. After training, the ANFIS linearizes the HPA response and thus, the obtained signal is extremely similar ...

  20. NOVEL DESIGN OF A BIOELECTRIC AMPLIFIER WITH MINIMIZED MAGNITUDE AND PHASE ERRORS

    Institute of Scientific and Technical Information of China (English)

    Mashhour Bani Amer; Assistant Professor

    2001-01-01

    A new design of a bioelectric amplifier that has better parameters than conventional designs is presented. The design allows the construction of bioelectric amplifier with improved parameters in terms of common-mode rejection ratio and phase and magnitude errors. The voltage gain is easily adapted to a wide range of biomedical applications. The experimental and simulation results of the designed bioelectric amplifier are also included.