WorldWideScience

Sample records for audio power amplifier

  1. 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

  2. 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...

  3. Multi Carrier Modulation Audio Power Amplifier with Programmable Logic

    DEFF Research Database (Denmark)

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

    2009-01-01

    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. To lower the EMI of switch-mode (class D) audio power a...

  4. 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 swit...

  5. 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 sw...

  6. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify the design, increase...... efficiency, reduce the product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented....

  7. Minimizing Crosstalk in Self Oscillating Switch Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Knott, Arnold; Ploug, Rasmus Overgaard

    2012-01-01

    The varying switching frequencies of self oscillating switch mode audio amplifiers have been known to cause interchannel intermodulation disturbances in multi channel configurations. This crosstalk phenomenon has a negative impact on the audio performance. The goal of this paper is to present a m...

  8. Debugging of Class-D Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Crone, Lasse; Pedersen, Jeppe Arnsdorf; Mønster, Jakob Døllner;

    2012-01-01

    Determining and optimizing the performance of a Class-D audio power amplier can be very dicult without knowledge of the use of audio performance measuring equipment and of how the various noise and distortion sources in uence the audio performance. This paper gives an introduction on how to measu...

  9. Self-oscillating modulators for direct energy conversion audio power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    Direct energy conversion audio power amplifier represents total integration of switching-mode power supply and Class D audio power amplifier into one compact stage, achieving high efficiency, high level of integration, low component count and eventually low cost. This paper presents how self-oscillating modulators can be used with the direct switching-mode audio power amplifier to improve its performance by providing fast hysteretic control with high power supply rejection ratio, open-loop stability and high bandwidth. Its operation is thoroughly analyzed and simulated waveforms of a prototype amplifier are presented. (au)

  10. Output impedance and stability of audio power amplifiers

    NARCIS (Netherlands)

    Schaink, T.

    2006-01-01

    This report is about the design of an audio amplifier which is stable for all passive loads. If stability analysis of an opamp is done, the ‘classical’ approach is to derive its transfer function. Investigation of the open loop gain and a phase/gain margin determine the stability of the opamp. Desig

  11. Direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, Michael A.E.

    2005-07-01

    This paper discusses the advantages and problems when implementing direct energy conversion switching-mode audio power amplifiers. It is shown that the total integration of the power supply and Class D audio power amplifier into one compact direct converter can simplify design, increase efficiency and integration level, reduce product volume and lower its cost. As an example, the principle of operation and the measurements made on a direct-conversion switching-mode audio power amplifier with active capacitive voltage clamp are presented. (au)

  12. Design and Research on Sigma-Delta Digital-to-Analog Converters for Audio Power Amplifiers

    OpenAIRE

    Puidokas, Vytenis

    2011-01-01

    The dissertation investigates the issues of analyzing a digital Sigma-Delta digital-to-analog converter (DAC) for audio power amplifiers. The main objects of research include a digital Sigma-Delta audio power DAC, improvement of its structure and an experimental research. The primary purpose of the dissertation is to suggest methods for improvement the structure of digital Sigma-Delta audio power DAC interpolator and the converter analysis. Disertacijoje nagrinėjami Sigma-Delta skaitmenini...

  13. Approaches to building single-stage AC/AC conversion switch-mode audio power amplifiers

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2004-01-01

    This paper discusses the possible topologies and promising approaches towards direct single-phase AC-AC conversion of the mains voltage for audio applications. When compared to standard Class-D switching audio power amplifiers with a separate power supply, it is expected that direct conversion...

  14. A high efficiency PWM CMOS class-D audio power amplifier

    Institute of Scientific and Technical Information of China (English)

    朱樟明; 刘帘曦; 杨银堂; 雷晗

    2009-01-01

    Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 μm CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 μA. The active area of the class-D audio power amplifier is about 1.47 × 1.52 mm2. With the good performance, the class-D audio power amplifier can be applied to several audio power systems.

  15. Integrating switch mode audio power amplifiers and electro dynamic loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier.......The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier....

  16. Active Electromagnetic Interference Cancelation for Automotive Switch-Mode Audio Power Amplifiers

    DEFF Research Database (Denmark)

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

    2009-01-01

    . Electromagnetic interference between switch-mode audio power amplifiers and receivers show the same physical obstacle as the described ANC endeavors are targeting. The principle of active electromagnetic interference cancelation (AEC) is derived in this paper on a theoretical basis with verifications...... in simulation and experiment. The resulting switch-mode audio power amplifier of this experiment keeps its high efficiency and is able to deliver the signal with less than 0.1 % distortion, while improving the source of electromagnetic interference by 15 dB....

  17. Frequency dependent loss analysis and minimization of system losses in switchmode audio power amplifiers

    DEFF Research Database (Denmark)

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

    2014-01-01

    In this paper, frequency dependent losses in switch-mode audio power amplifiers are analyzed and a loss model is improved by taking the voltage dependence of the parasitic capacitance of MOSFETs into account. The estimated power losses are compared to the measurement and great accuracy is achieved...

  18. An audio FIR-DAC in a BCD process for high power Class-D amplifiers

    NARCIS (Netherlands)

    Doorn, T.S.; Tuijl, van E.; Schinkel, D.; Annema, A.J.; Berkhout, M.; Nauta, B.

    2005-01-01

    A 322 coefficient semi-digital FIR-DAC using a 1-bit PWM input signal was designed and implemented in a high voltage, audio power bipolar CMOS DMOS (BCD) process. This facilitates digital input signals for an analog class-D amplifier in BCD. The FIR-DAC performance depends on the ISI-resistant natur

  19. Efficiency of Switch-Mode Power Audio Amplifiers - Test Signals and Measurement Techniques

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Knott, Arnold; Andersen, Michael A. E.

    2016-01-01

    . An alternative signal is proposed for test purposes. The efficiency of a switch-mode power audio amplifier is modelled and measured with both sine wave and the proposed test signal as inputs. The results show that the choice of switching devices with low on resistances are unfairly favored when measuring...... the efficiency with sine waves. A 10% efficiency improvement was found for low power outputs. It is therefore of great importance to use proper test signals when measuring the efficiency....

  20. A power supply error correction method for single-ended digital audio class D amplifiers

    Science.gov (United States)

    Yu, Zeqi; Wang, Fengqin; Fan, Yangyu

    2016-12-01

    In single-ended digital audio class D amplifiers (CDAs), the errors caused by power supply noise in the power stages degrade the output performance seriously. In this article, a novel power supply error correction method is proposed. This method introduces the power supply noise of the power stage into the digital signal processing block and builds a power supply error corrector between the interpolation filter and the uniform-sampling pulse width modulation (UPWM) lineariser to pre-correct the power supply error in the single-ended digital audio CDA. The theoretical analysis and implementation of the method are also presented. To verify the effectiveness of the method, a two-channel single-ended digital audio CDA with different power supply error correction methods is designed, simulated, implemented and tested. The simulation and test results obtained show that the method can greatly reduce the error caused by the power supply noise with low hardware cost, and that the CDA with the proposed method can achieve a total harmonic distortion + noise (THD + N) of 0.058% for a -3 dBFS, 1 kHz input when a 55 V linear unregulated direct current (DC) power supply (with the -51 dBFS, 100 Hz power supply noise) is used in the power stages.

  1. Comparison of Power Supply Pumping of Switch-Mode Audio Power Amplifiers with Resistive Loads and Loudspeakers as Loads

    DEFF Research Database (Denmark)

    Knott, Arnold; Petersen, Lars Press

    2013-01-01

    Power supply pumping is generated by switch-mode audio power amplifiers in half-bridge configuration, when they are driving energy back into their source. This leads in most designs to a rising rail voltage and can be destructive for either the decoupling capacitors, the rectifier diodes in the p...

  2. Integrating switch mode audio amplifiers and electro dynamic loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier.......The work presented in this paper is related to integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker's voice coil as output filter, and the magnetic structure as heatsink for the amplifier....

  3. High efficiency class-Ⅰ audio power amplifier using a single adaptive supply

    Institute of Scientific and Technical Information of China (English)

    Peng Zhenfei; Yang Shanshan; Feng Yong; Liu Yang; Hong Zhiliang

    2012-01-01

    A high efficiency class-Ⅰ linear audio power amplifier (PA) with an adaptive supply is presented.Its efficiency is improved by a dynamic supply to reduce the power transistors' voltage drop.A gain compression technique is adopted to make the amplifier accommodate a single positive supply.Circuit complicity and chip area are reduced because no charge pump is necessary for the negative supply.A common shared mode voltage and a symmetric layout pattern are used to minimize the non-linearity.A peak efficiency of 80% is reached at peak output power.The measured THD+N before and after the supply switching point are 0.01% and 0.05%,respectively.The maximum output power is 410 mW for an 8 Ω speaker load.Unlike switching amplifiers,the class-Ⅰ amplifier operates as a linear amplifier and hence has a low EMI.The advantage of a high efficiency and low EMI makes the class-Ⅰ amplifier suitable for portable and RF sensitive applications.

  4. Investigation of Energy Consumption and Sound Quality for Class-D Audio Amplifiers using Tracking Power Supplies

    DEFF Research Database (Denmark)

    Yamauchi, Akira; Schneider, Henrik; Knott, Arnold;

    2015-01-01

    The main advantage of Class-D audio amplifiers is high efficiency which is often stated to be more than 90 % but at idle or low power levels the efficiency is much lower. The waste energy is an environmental concern, a concern in mobile applications where long battery operation is required...... power supply tracking and its influence on power losses, audio performance and environmental impact for a 130 W class-D amplifier prototype as well as a commercialized class-D amplifier. Both modeled and experimental results verify that a large improvement of efficiency can be achieved. The total...

  5. An audio FIR-DAC in a BCD process for high power Class-D amplifiers

    OpenAIRE

    Doorn, T.S.; Tuijl, van, B.A.J.; Schinkel, D.; Annema, A.J.; Berkhout, M.; Nauta, B.

    2005-01-01

    A 322 coefficient semi-digital FIR-DAC using a 1-bit PWM input signal was designed and implemented in a high voltage, audio power bipolar CMOS DMOS (BCD) process. This facilitates digital input signals for an analog class-D amplifier in BCD. The FIR-DAC performance depends on the ISI-resistant nature of this PWM-signal. An impulse response with only positive coefficients was chosen, because of its resistance to deadzone and mismatch. With a DAC current of 0.5 mA, the dynamic range is 111 dB (...

  6. A dual mode charge pump with adaptive output used in a class G audio power amplifier*

    Institute of Scientific and Technical Information of China (English)

    Feng Yong; Peng Zhenfei; Yang Shanshan; Hong Zhiliang; Liu Yang

    2011-01-01

    A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented. According to the amplitude of the input signals, the charge pump has two level output voltage rails available to save power. It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation. Also, dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range. The prototype is implemented in 0.18μm 3.3 V CMOS technology. Experimental results show that the maximum power efficiency of the charge pump is 79.5% @ 0.5x mode and 83.6% @ lx mode. The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control. An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results.

  7. Practical considerations for integrating switch mode audio amplifiers and loudspeakers for a higher power efficiency

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    An integration of electrodynamic loudspeakers and switch mode amplifiers has earlier been proposed in [1]. The work presented in this paper is related to the practical aspects of integration of switch mode audio amplifiers and electro dynamic loudspeakers, using the speaker’s voice coil as output...

  8. Audio power amplifier techniques with energy efficient power conversion. Vol. 1

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Karsten

    1998-04-01

    A fundamental study of both analog and digital pulse modulation methods is carried out. A novel class of multi-level pulse modulation methods - Phase Shifted Carrier Pulse Width Modulation (PSCPWM) - is introduced and show to have several advantageous features, primarily caused by the much improved synthesis of the modulating signal. Enhanced digital pulse modulation methods for digital Pulse Modulation Amplifier (PMA) systems are investigated, and a simple methodology for digital PWM modulator synthesis is devised. It is concluded, that the modulator performance is not a limitation in the system, regardless of the domain of modulator implementation. Power conversion in PMA systems is adressed from the perspective of both linearity and efficienty optimization. Based on detailed studies of the distortion mechanisms in the power conversion stage it is concluded, that this is the fundamental limitation on system performance due to several physical limitations. The analysis of general power stage efficiency concludes that dramatic improvements in energy efficiency are possible with PMA systems that are optimized for efficiency. A control system design methodology is devised as a platform for synthesis of robust control systems. Investigations of three fundamental control structures show that even simple control systems offer a remarkable value, although the considered topologies also have their limitations which is verified by practical evaluation in hardware. A novel control method is introduced - Multivariable Enhanced Cascade Control (MECC). MECC provides flexible control over all essential system parameters and is furthermore simple in realization. Practical evaluation of a MECC based PMA shows state-of-the-art performance. The application of non-linear control methods is investigated with the introduction of an enhanced non-linear control/modulator topology. Although the non-linear controller is theoretically interesting, the method proves to suffer from various

  9. BTL音频功率放大电路教学研讨%Teaching research on BTL audio power amplifier

    Institute of Scientific and Technical Information of China (English)

    曹钟林

    2015-01-01

    In the course of 《Analog Electronic Technology》in higher vocational colleges, the OCL and OTL audio power amplifier circuit is more and more widely used, and the BTL (Transformer Less Balanced balanced output transformer) audio power amplifier circuit is often omitted. The advantages of BTL circuit and OTL circuit are obvious, and it should be given some attention. This paper analysis the structure, principle and design method of BTL circuit from the perspective of teaching.%在高职院校的《模拟电子技术》课程中,OCL和OTL音频功率放大电路讲解的较多,而应用较为广泛的BTL ( Balanced Transformer Less平衡无输出变压器)音频功率放大电路往往略讲, BTL电路较OCL和OTL电路优点是显而易见的,应当给予一定的关注。本文从教学的角度解析BTL电路的结构、原理及设计制作思路。

  10. Practical Implementation and Error Analysis of PSCPWM-Based Switching Audio Power Amplifiers

    DEFF Research Database (Denmark)

    Christensen, Frank Schwartz; Frederiksen, Thomas Mansachs; Andersen, Michael Andreas E.;

    1999-01-01

    The paper presents an in-depth analysis of practical results for Parallel Phase-Shifted Carrier Pulse-Width Modulation (PSCPWM) - amplifier. Spectral analyses of error sources involved in PSCPWM are presented. The analysis is performed both by numerical means in MATLAB and by simulation in PSPICE......, followed by practical verification on a prototype. A toolbox for MATLAB has been developed to ease the complex analysis....

  11. 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 unde...

  12. Investigation of crosstalk in self oscillating switch mode audio power amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Haagen; Ploug, Rasmus Overgaard; Iversen, Niels Elkjær;

    2012-01-01

    Self oscillating switch mode power ampliers are known to be susceptible to interchannel disturbances also known as crosstalk. This phenomenon has a signicant impact on the performance of an amplier of this type. The goal of this paper is to investigate the presence and origins of crosstalk in a t...

  13. 防破音D类音频功放的设计与应用%Design and Application of Non-clip Class-D Audio Power Amplifier

    Institute of Scientific and Technical Information of China (English)

    杜虹; 阮颐; 刘燕涛

    2012-01-01

    With the popularization of multi-media portable devices, audio power amplifier has become a basic component of audio part. Class-D audio power amplifier is widely used because of its high efficiency and excellent characteristics. In portable devices, audio power amplifier will produce clipping distortion when the input music signal is over level or the voltage of battery is low. Non-clip technology will provide a perfect solution with automatic gain control. This paper analyzed the common Non-clip technology, and proposed the design and application of an improved AGC method in Class-D amplifier. The improved AGC method detects the distortion of output PWM signal, and automatically control the gain by the PWM waveform modulated by the Non-clip circuit, eventually realized the maximum output power without distortion.%随着多媒体便携设备的普及,音频功放已经成为音频部分的标准配置,D类功放以其高品质高效的特点得到了越来越广泛的应用。在便携产品中,音频功放由于输入音乐信号过大或者电源电压过低,会产生削顶失真。采用防破音技术,可以通过自动增益调节技术来提供一个完美的解决方案。文章介绍了常见的防破音技术,提出了一种改进的AGC(自动增益控制)技术在D类功放中的设计与应用。改进的AGC技术通过对PWM输出的采样来判断失真程度,依据失真程度用防破音电路产生的PWM波形来自动调节运放增益,实现最大功率的无失真输出。

  14. Efficient audio power amplification - challenges

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Michael A.E.

    2005-07-01

    For more than a decade efficient audio power amplification has evolved and today switch-mode audio power amplification in various forms are the state-of-the-art. The technical steps that lead to this evolution are described and in addition many of the challenges still to be faced and where extensive research and development are needed is covered. (au)

  15. 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...

  16. Ferrite bead effect on Class-D amplifier audio quality

    OpenAIRE

    Haddad, Kevin El; Mrad, Roberto; Morel, Florent; Pillonnet, Gael; Vollaire, Christian; Nagari, Angelo

    2014-01-01

    International audience; This paper studies the effect of ferrite beads on the audio quality of Class-D audio amplifiers. This latter is a switch-ing circuit which creates high frequency harmonics. Generally, a filter is used at the amplifier output for the sake of electro-magnetic compatibility (EMC). So often, in integrated solutions, this filter contains ferrite beads which are magnetic components and present nonlinear behavior. Time domain measurements and their equivalence in frequency do...

  17. Predistortion of a Bidirectional Cuk Audio Amplifier

    DEFF Research Database (Denmark)

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

    2014-01-01

    Some non-linear amplifier topologies are capable of providing a larger voltage gain than one from a DC source, which could make them suitable for various applications. However, the non-linearities introduce a significant amount of harmonic distortion (THD). Some of this distortion could be reduce...

  18. 基于AD8369的数字音频广播传输系统的研究与实现%Design of Digital Audio Broadcasting Power Amplifier System Based on AD8369

    Institute of Scientific and Technical Information of China (English)

    陆明莹; 刘石; 王国裕; 张红升

    2012-01-01

    This paper introduces in detail the structure and theory of AD8369,it functions inside as a digitally controlled variable gain amplifier,Digital Audio Broadcasting Transmitting System based on A8369 was designed.The system used digitally controlled variable gain amplifier device AD8369 fills the power amplifier in the original Digital Audio Broadcasting system.It presents the block of the structure of system,the hardware structure,the software flow chart,timing control chart,testing and certification and descripes in detail the operational principle and process of the system.%该文详细地介绍了具有内部可控功能的数字可控增益放大器件AD8369的结构与工作原理,设计了基于AD8369的数字音频广播传输系统。本系统采用的数字可控增益放大器件AD8369填补了原数字音频广播系统中没有输出功放的空白。该文给出了系统的结构框图、硬件结构框图、软件流程图和时序控制图及测试和验证,详细介绍了系统工作的原理和流程。

  19. 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.

  20. Design of audio amplifier%音响放大器设计

    Institute of Scientific and Technical Information of China (English)

    张文娟

    2015-01-01

    According to traditional audio amplifier design shortcomings, combined with modern electronic technology, using audio amplification IC, an approach of the audio amplifier is designed. Firstly,analysis the principle and circuit of the audio amplifier.then introduces the power circuit design, power rectifier, power filtering in detail;preamplifier design;PA design.At last, debugging the major technical indicators such as the effective frequency , THD, the rated output power, input impedance, output impedance etc. Debugging results showed that the main technical indicators have reached the design requirements, which has a good value for money, ideal for audio output.%针对传统音响放大的设计缺点,结合现代电子技术,采用音响放大集成电路,设计了一种音响放大器。首先分析了音响放大器的工作原理及电路组成,然后详细介绍了电源电路设计、电源整流、电源滤波;前置放大器设计;功率放大器设计;最后,分别对有效频率、总谐波失真、额定输出功率、输入阻抗、输出阻抗等主要技术指标进行了调试。调试结果表明,主要技术指标均达到设计要求,该设计具有较好的性价比,音响输出非常理想。

  1. Analysis of current-bidirectional buck-boost based switch-mode audio amplifier

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus;

    2011-01-01

    in a differential mode buckbased amplifier with a boost converter as power supply. The averaged switch modelling of the differential mode current bidirectional topology is also used, in order to analyze the steady state and frequency-wise behaviour of this converter and parameterize it to meet the design criteria......The following studdy was carried out in order to assses quantitatively the performannce of the buck--boost converter whhen used as swiitch-mode audio amplifier. It comprises of, to beggin with, the de limitation of design criteria bassed on the state of-the-art solution, which is based...

  2. A 240W Monolithic Class-D Audio Amplifier Output Stage

    DEFF Research Database (Denmark)

    Nyboe, Flemming; Kaya, Cetin; Risbo, Lars;

    2006-01-01

    A single-channel class-D audio amplifier output stage outputs 240W undipped into 4Omega 0.1% open-loop THD+N allows using the device in a fully-digital audio signal path with no feedback. The output current capability is plusmn18A and the part is fabricated in a 0.4mum/1.8mum high-voltage Bi...

  3. A High-Voltage Class D Audio Amplifier for Dielectric Elastomer Transducers

    DEFF Research Database (Denmark)

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

    2014-01-01

    Dielectric Elastomer (DE) transducers have emerged as a very interesting alternative to the traditional electrodynamic transducer. Lightweight, small size and high maneuverability are some of the key features of the DE transducer. An amplifier for the DE transducer suitable for audio applications...

  4. Analisys of Current-Bidirectional Buck-Boost Based Automotive Switch-Mode Audio Amplifier

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael A. E.; Kjærgaard, Claus;

    2011-01-01

    The following study was carried out in order to assess quantitatively the performance of the buck-boost converter when used as switch-mode audio amplifier. It comprises of, to begin with, the delimitation of design criteria based on the state-ofthe- art solution, which is based in a differential ...

  5. 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.

  6. Class D audio amplifier with 4th order output filter and self-oscillating full-state hysteresis based feedback driving capacitive transducers

    DEFF Research Database (Denmark)

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

    2014-01-01

    A practical solution is presented for the design of a non-isolated high voltage DC/AC power converter. The converter is intended to be used as a class D audio amplifier for a Dielectric Electro Active Polymer (DEAP) transducer. A simple and effective hysteretic control scheme for the converter (b...

  7. Linearisation of RF Power Amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck

    2001-01-01

    This thesis deals with linearisation techniques of RF power amplifiers (PA), PA design techniques and integration of the necessary building blocks in a CMOS technology. The opening chapters introduces the theory of transmitter architectures, RF-signal representation and the principles of digital...... modulation. Furthermore different types of power amplifiers, models and measures of non-linearities are presented. A chapter is also devoted to different types of linearisation systems. The work carried out and described in this thesis can be divided into a more theoretical and system oriented treatment...... 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...

  8. Small and lightweight power amplifiers

    Science.gov (United States)

    Shams, Qamar A.; Barnes, Kevin N.; Fox, Robert L.; Moses, Robert W.; Bryant, Robert G.; Robinson, Paul C.; Shirvani, Mir

    2002-07-01

    The control of u wanted structural vibration is implicit in most of NASA's programs. Currently several approaches to control vibrations in large, lightweight, deployable structures and twin tail aircraft at high angles of attack are being evaluated. The Air Force has been examining a vertical tail buffet load alleviation system that can be integrated onboard an F/A-18 and flown. Previous wind tunnel and full-scale ground tests using distributed actuators have shown that the concept works; however, there is insufficient rom available onboard an F/A-18 to store current state-of- the-art system components such as amplifiers, DC-to-DC converter and a computer for performing vibration suppression. Sensor processing, power electronics, DC-to-DC converters, and control electronics that may be collocated with distributed actuators, are particularly desirable. Such electronic system would obviate the need for complex, centralized, control processing and power distribution components that will eliminate the weight associated with lengthy wiring and cabling networks. Several small and lightweight power amplifiers ranging from 300V pp to 650V pp have been designed using off the shelf components for different applications. In this paper, the design and testing of these amplifiers will be presented under various electrical loads.

  9. Class D audio amplifiers for high voltage capacitive transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis

    with a large volume of the loudspeaker enclosure. Piezoelectric loudspeakers suffers from the poor power handling capability of the piezoelectric ceramic. However a niche is found in the market of hydrophones, because of the excellent impedance matching between the piezoelectric transducer and water...

  10. Determination of over current protection thresholds for class D audio amplifiers

    DEFF Research Database (Denmark)

    Nyboe, Flemming; Risbo, L; Andreani, Pietro

    2005-01-01

    Monolithic class-D audio amplifiers typically feature built-in over current protection circuitry that shuts down the amplifier in case of a short circuit on the output speaker terminals. To minimize cost, the threshold at which the device shuts down must be set just above the maximum current...... that can flow in the loudspeaker during normal operation. The current required is determined by the complex loudspeaker impedance and properties of the music signals played. This work presents a statistical analysis of peak output currents when playing music on typical loudspeakers for home entertainment....

  11. Comparative Study of Si and SiC MOSFETs for High Voltage Class D Audio Amplifiers

    DEFF Research Database (Denmark)

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

    2014-01-01

    Silicon (Si) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) are traditional utilised in class D audio amplifiers. It has been proposed to replace the traditional inefficient electrodynamic transducer with the electrostatic transducer. This imposes new high voltage requirements...... on the MOSFETs of class D amplifiers, and significantly reduces the selection of suitable MOSFETs. As a consequence it is investigated, if Silicon-Carbide (SiC) MOSFETs could represent a valid alternative. The theory of pulse timing errors are revisited for the application of high voltage and capactive loaded...... class D amplifiers. It is shown, that SiC MOSFETs can compete with Si MSOFETs in terms of THD. Validation is done using simulations and a 500 V amplifier driving a 100 nF load. THD+N below 0.3 % is reported...

  12. 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....

  13. Carrier Distortion in Hysteretic Self-Oscillating Class-D Audio Power

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Kofod; Andersen, Michael A. E.

    2009-01-01

    and output is required, such as in audio power amplifiers or xDSL drivers. From an average-mode point of view, carrier distortion is shown to be caused by nonlinear variation of the hysteretic comparator input average voltage with the output average voltage. This easily causes total harmonic distortion.......03% THD from 100 Hz to 6.7 kHz. Carrier distortion is shown to account for this limitation in THD performance....

  14. Safe-commutation principle for direct single-phase AC-AC converters for use in audio power amplification

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2004-01-01

    This paper presents an alternative safe commutation principle for a single phase bidirectional bridge, for use in the new generation of direct single-stage AC-AC audio power amplifiers. As compared with the bridge commutation with load current or source voltage sensing, in this approach...

  15. An Envelope Hammerstein Model for Power Amplifiers

    Institute of Scientific and Technical Information of China (English)

    Hua-Dong Wang; Song-Bai He; Jing-Fu Bao; Zheng-De Wu

    2007-01-01

    In this paper, an envelope Hammerstein(EH) model is introduced to describe dynamic inputoutput characteristics of RF power amplifiers. In the modeling approach, we use a new truncation method and an established nonlinear time series method to determine model structure. Then, we discuss the process of model parameter extraction in detailed. Finally, a 2 W WCDMA power amplifier is measured to verify the performance of EH model, and good agreement between model output and measurement result shows our model can accurately predict output characteristic of the power amplifier.

  16. High power Ka band TWT amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Golkowski, C.; Ivers, J.D.; Nation, J.A.; Wang, P.; Schachter, L.

    1999-07-01

    Two high power 35 GHz TWT amplifiers driven by a relativistic pencil, 850 kV, 200A electron beam have been assembled and tested. The first had a dielectric slow wave structure and was primarily used to develop diagnostics, and to gain experience in working with high power systems in Ka band. The source of the input power for the amplifier was a magnetron producing a 30 kW, 200ns long pulse of which 10 kW as delivered to the experiment. The 30 cm long dielectric (Teflon) amplifier produced output power levels of about 1 MW with a gain of about 23 dB. These results are consistent with expectations from PIC code simulations for this arrangement. The second amplifier, which is a single stage disk loaded slow wave structure, has been designed. It consists of one hundred uniform cells with two sets of ten tapered calls at the ends to lower the reflection coefficient. The phase advance per cell is {pi}/2. The amplifier passband extends from 28 to 40 GHz. It is designed to increase the output power to about 20 MW. The amplifier is in construction and will be tested in the near future. Details of the design of both systems will be provided and initial results from the new amplifier presented.

  17. High power regenerative laser amplifier

    Science.gov (United States)

    Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

    1994-02-08

    A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

  18. High Efficiency Microwave Power Amplifier (HEMPA) Design

    Science.gov (United States)

    Sims, W. Herbert

    2004-01-01

    This paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

  19. System Level Power Optimization of Digital Audio Back End for Hearing Aids

    DEFF Research Database (Denmark)

    Pracny, Peter; Jørgensen, Ivan Harald Holger; Bruun, Erik

    2016-01-01

    the interpolation filter and the SD modulator on the system level so that the switching frequency of the Class D PA - the main power consumer in the back end - is minimized. A figure-of-merit (FOM) which allows judging the power consumption of the digital part of the back end early in the design process is used...... to track the hardware and power demands as the tradeoffs of the system level parameters are investigated. The result is the digital part of the back end optimized with respect to power which provides audio performance comparable to state-of-theart. A combination of system level parameters leading...... to the lowest switching frequency of the Class D power amplifier reported in literature for the SD modulatorbased back end is derived using this approach....

  20. Laser Cooled High-Power Fiber Amplifier

    CERN Document Server

    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 of a small deviation in the value of the amplified signal on the temperature of the fiber with the fixed distribution of the Tm3+ions in the fiber cladding is investigated.

  1. High power, high beam quality regenerative amplifier

    Science.gov (United States)

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  2. Differential Passive Circuit Modelling with Pentapole Impedance Matrices Application to an Integrated Audio Switching Amplifier for Portable Devices

    OpenAIRE

    Mrad, Roberto; Morel, Florent; Pillonnet, Gael; Vollaire, Christian; Labrousse, Denis

    2011-01-01

    International audience; In this paper a novel method to model the passive parts of differential output system is presented. This approach, based on impedance matrices, models conducted EMI and takes into account component non-idealities. It is not only able to deal with common mode but also differential mode and with conversion between the two modes. This method is experimentally applied to the passive output part of an audio differential switching amplifier dedicated to mobile phone applicat...

  3. Design Of A Doherty Power Amplifier For GSM Systems

    Directory of Open Access Journals (Sweden)

    Saad Wasmi Osman

    2013-04-01

    Full Text Available This paper presents the design and analysis of Doherty power amplifier. The Doherty amplifier is used in  a base station for mobile system because of its high efficiency. The class AB power amplifier used in the configuration of the main and auxiliary amplifier. The result obtained shows that the Doherty power amplifier can be used on a wide band spectrum, the amplifier works at 900MHz and has very good power added efficiency (PAE and gain. The amplifier can also work at 1800MHz at input power greater than 20dBm. 

  4. High Power Amplifier and Power Supply

    Science.gov (United States)

    Duong, Johnny; Stride, Scot; Harvey, Wayne; Haque, Inam; Packard, Newton; Ng, Quintin; Ispirian, Julie Y.; Waian, Christopher; Janes, Drew

    2008-01-01

    A document discusses the creation of a high-voltage power supply (HVPS) that is able to contain voltages up to -20 kV, keep electrical field strengths to below 200 V/mil (approximately equal to 7.87 kV/mm), and can provide a 200-nanosecond rise/fall time focus modulator swinging between cathode potential of 16.3 kV and -19.3 kV. This HVPS can protect the 95-GHz, pulsed extended interaction klystron (EIK) from arcs/discharges from all sources, including those from within the EIK fs vacuum envelope. This innovation has a multi-winding pulse transformer design, which uses new winding techniques to provide the same delays and rise/fall times (less than 10 nanoseconds) at different potential levels ranging from -20 kV to -16 kV. Another feature involves a high-voltage printed-wiring board that was corona-free at -20 kV DC with a 3- kV AC swing. The corona-free multilayer high-voltage board is used to simulate fields of less than 200 V/mil (approximately equal to 7.87 kV/mm) at 20 kV DC. Drive techniques for the modulator FETs (field-effect transistors) (four to 10 in a series) were created to change states (3,000-V swing) without abrupt steps, while still maintaining required delays and transition times. The packing scheme includes a potting mold to house a ten-stage modulator in the space that, in the past, only housed a four-stage modulator. Problems keeping heat down were solved using aluminum oxide substrate in the high-voltage section to limit temperature rise to less than 10 while withstanding -20 kV DC voltage and remaining corona-free.

  5. 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.

  6. Mixed-Signal Architectures for High-Efficiency and Low-Distortion Digital Audio Processing and Power Amplification

    Directory of Open Access Journals (Sweden)

    Pierangelo Terreni

    2010-01-01

    Full Text Available The paper addresses the algorithmic and architectural design of digital input power audio amplifiers. A modelling platform, based on a meet-in-the-middle approach between top-down and bottom-up design strategies, allows a fast but still accurate exploration of the mixed-signal design space. Different amplifier architectures are configured and compared to find optimal trade-offs among different cost-functions: low distortion, high efficiency, low circuit complexity and low sensitivity to parameter changes. A novel amplifier architecture is derived; its prototype implements digital processing IP macrocells (oversampler, interpolating filter, PWM cross-point deriver, noise shaper, multilevel PWM modulator, dead time compensator on a single low-complexity FPGA while off-chip components are used only for the power output stage (LC filter and power MOS bridge; no heatsink is required. The resulting digital input amplifier features a power efficiency higher than 90% and a total harmonic distortion down to 0.13% at power levels of tens of Watts. Discussions towards the full-silicon integration of the mixed-signal amplifier in embedded devices, using BCD technology and targeting power levels of few Watts, are also reported.

  7. Power amplifiers in CMOS technology : a contribution to power amplifier theory and techniques

    NARCIS (Netherlands)

    Acar, Mustafa

    2011-01-01

    In order to meet the demands from the market on cheaper, miniaturized mobile communications devices realization of RF power amplifiers(PAs) in the mainstream CMOS technology is essential. In general, CMOS PAs require high supply-voltage to decrease the matching network losses and for high output pow

  8. Audio-visual synchrony and feature-selective attention co-amplify early visual processing.

    Science.gov (United States)

    Keitel, Christian; Müller, Matthias M

    2016-05-01

    Our brain relies on neural mechanisms of selective attention and converging sensory processing to efficiently cope with rich and unceasing multisensory inputs. One prominent assumption holds that audio-visual synchrony can act as a strong attractor for spatial attention. Here, we tested for a similar effect of audio-visual synchrony on feature-selective attention. We presented two superimposed Gabor patches that differed in colour and orientation. On each trial, participants were cued to selectively attend to one of the two patches. Over time, spatial frequencies of both patches varied sinusoidally at distinct rates (3.14 and 3.63 Hz), giving rise to pulse-like percepts. A simultaneously presented pure tone carried a frequency modulation at the pulse rate of one of the two visual stimuli to introduce audio-visual synchrony. Pulsed stimulation elicited distinct time-locked oscillatory electrophysiological brain responses. These steady-state responses were quantified in the spectral domain to examine individual stimulus processing under conditions of synchronous versus asynchronous tone presentation and when respective stimuli were attended versus unattended. We found that both, attending to the colour of a stimulus and its synchrony with the tone, enhanced its processing. Moreover, both gain effects combined linearly for attended in-sync stimuli. Our results suggest that audio-visual synchrony can attract attention to specific stimulus features when stimuli overlap in space.

  9. Series-Tuned High Efficiency RF-Power Amplifiers

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    2008-01-01

    An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits.......An approach to high efficiency RF-power amplifier design is presented. It addresses simultaneously efficiency optimization and peak voltage limitations when transistors are pushed towards their power limits....

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

    Energy Technology Data Exchange (ETDEWEB)

    Ramarao, B.V., E-mail: bvram@barc.gov.in [Ion Accelerator Development Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Sonal, S.; Mishra, J.K.; Pande, M.; Singh, P. [Ion Accelerator Development Division, Bhabha Atomic Research Center, Mumbai 400085 (India); Kumar, G.; Mukherjee, J. [Indian Institute of Technology, Powai, Mumbai 400076 (India)

    2014-01-21

    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.

  11. Optimal Relay Power Allocation for Amplify-and-Forward Relay Networks with Non-linear Power Amplifiers

    OpenAIRE

    Zhang, Chao; Ren, Pinyi; Peng, Jingbo; Wei, Guo; Du, Qinghe; Wang, Yichen

    2011-01-01

    In this paper, we propose an optimal relay power allocation of an Amplify-and-Forward relay networks with non-linear power amplifiers. Based on Bussgang Linearization Theory, we depict the non-linear amplifying process into a linear system, which lets analyzing system performance easier. To obtain spatial diversity, we design a complete practical framework of a non-linear distortion aware receiver. Consider a total relay power constraint, we propose an optimal power allocation scheme to maxim...

  12. 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.

  13. High Efficiency Microwave Power Amplifier: From the Lab to Industry

    Science.gov (United States)

    Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Since the beginnings of space travel, various microwave power amplifier designs have been employed. These included Class-A, -B, and -C bias arrangements. However, shared limitation of these topologies is the inherent high total consumption of input power associated with the generation of radio frequency (RF)/microwave power. The power amplifier has always been the largest drain for the limited available power on the spacecraft. Typically, the conversion efficiency of a microwave power amplifier is 10 to 20%. For a typical microwave power amplifier of 20 watts, input DC power of at least 100 watts is required. Such a large demand for input power suggests that a better method of RF/microwave power generation is required. The price paid for using a linear amplifier where high linearity is unnecessary includes higher initial and operating costs, lower DC-to-RF conversion efficiency, high power consumption, higher power dissipation and the accompanying need for higher capacity heat removal means, and an amplifier that is more prone to parasitic oscillation. The first use of a higher efficiency mode of power generation was described by Baxandall in 1959. This higher efficiency mode, Class-D, is achieved through distinct switching techniques to reduce the power losses associated with switching, conduction, and gate drive losses of a given transistor.

  14. An RF Power Amplifier in a Digital CMOS Process

    DEFF Research Database (Denmark)

    Nielsen, Per Asbeck; Fallesen, Carsten

    2002-01-01

    A two stage class B power amplifier for 1.9 GHz is presented. The amplifier is fabricated in a standard digital EPI-CMOS process with low resistivity substrate. The measured output power is 29 dBm in a 50 Omega load. A design method to find the large signal parameters of the output transistor...

  15. Efficient Power Amplifier for Motor Control

    Science.gov (United States)

    Brown, R. J.

    1986-01-01

    Pulse-width-modulated amplifier supplies high current as efficiently as low current needed for starting and running motor. Key to efficiency of motor-control amplifier is V-channel metal-oxide/semiconductor transistor Q1. Device has low saturation resistance. However, has large gate input capacitance and small margin between its turn-on voltage and maximum allowable gate-to-source voltage. Circuits for output stages overcome limitations of VMOS device.

  16. Low power RF amplifier circuit for ion trap applications

    Science.gov (United States)

    Noriega, J. R.; García-Delgado, L. A.; Gómez-Fuentes, R.; García-Juárez, A.

    2016-09-01

    A low power RF amplifier circuit for ion trap applications is presented and described. The amplifier is based on a class-D half-bridge amplifier with a voltage mirror driver. The RF amplifier is composed of an RF class-D amplifier, an envelope modulator to ramp up the RF voltage during the ion analysis stage, a detector or amplitude demodulation circuit for sensing the output signal amplitude, and a feedback amplifier that linearizes the steady state output of the amplifier. The RF frequency is set by a crystal oscillator and the series resonant circuit is tuned to the oscillator frequency. The resonant circuit components have been chosen, in this case, to operate at 1 MHz. In testings, the class-D stage operated at a maximum of 78 mW at 1.1356 MHz producing 225 V peak.

  17. High power solid state rf amplifier for proton accelerator.

    Science.gov (United States)

    Jain, Akhilesh; Sharma, Deepak Kumar; Gupta, Alok Kumar; Hannurkar, P R

    2008-01-01

    A 1.5 kW solid state rf amplifier at 352 MHz has been developed and tested at RRCAT. This rf source for cw operation will be used as a part of rf system of 100 MeV proton linear accelerator. A rf power of 1.5 kW has been achieved by combining output power from eight 220 W rf amplifier modules. Amplifier modules, eight-way power combiner and divider, and directional coupler were designed indigenously for this development. High efficiency, ease of fabrication, and low cost are the main features of this design.

  18. Energy Efficient and Compact RF High-Power Amplifiers

    NARCIS (Netherlands)

    Calvillo Cortés, D.A.

    2014-01-01

    The main objectives of this thesis are to improve the energy efficiency and physical form-factor of high-power amplifiers in base station applications. As such, the focus of this dissertation is placed on the outphasing amplifier concept, which can offer high-efficiency, good linearity and excellent

  19. Dual Band High Efficiency Power Amplifier Based on CRLH Lines

    Directory of Open Access Journals (Sweden)

    D. Segovia-Vargas

    2009-12-01

    Full Text Available In this paper we propose the use of Composite Right/Left Hand (CRLH and Extended Composite Right/Left Hand (ECRLH transmission lines for the design of dual band high efficiency power amplifiers working in CE class. The harmonic termination can be synthesized using the meta-lines is particularly suitable for CE class amplifiers, which have a termination not as sensitive to the third harmonic as F class amplifier. This paper presents the design procedure and the design equations. The nonlinear phase response of a CRLH and ECRLH transmission line has been utilized to design arbitrary dual-band amplifiers.

  20. 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...

  1. 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.

  2. Thermal Effects in High-Power Fiber Amplifiers

    DEFF Research Database (Denmark)

    Hansen, Kristian Rymann; Lægsgaard, Jesper

    2011-01-01

    The effect of temperature gradients in Yb-doped fiber amplifiers is studied numerically. We investigate the dependence of the mode area on the signal power, and compare forward and backward pumping schemes.......The effect of temperature gradients in Yb-doped fiber amplifiers is studied numerically. We investigate the dependence of the mode area on the signal power, and compare forward and backward pumping schemes....

  3. Thermally induced nonlinear mode coupling in high power fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas T.;

    2013-01-01

    Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W.......Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W....

  4. 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

  5. 2250-MHz High Efficiency Microwave Power Amplifier (HEMPA)

    Science.gov (United States)

    Sims, W. Herbert; Bell, Joseph L. (Technical Monitor)

    2001-01-01

    Tnis paper will focus on developing an exotic switching technique that enhances the DC-to-RF conversion efficiency of microwave power amplifiers. For years, switching techniques implemented in the 10 kHz to 30 MHz region have resulted in DC-to-RF conversion efficiencies of 90-95-percent. Currently amplifier conversion efficiency, in the 2-3 GHz region approaches, 10-20-percent. Using a combination of analytical modeling and hardware testing, a High Efficiency Microwave Power Amplifier was built that demonstrated conversion efficiencies four to five times higher than current state of the art.

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

    Institute of Scientific and Technical Information of China (English)

    Zheng Lei; Zhang Jiahong; Chen Zhangyuan; Wu Deming; Xu Anshi

    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.

  7. Audio- and TV-products. Power consumption reduction in audio- and TV-products. Final report; Audio- og TV-produkter. Effektminimering i audio- og TV-produkter: Afsluttende rapport

    Energy Technology Data Exchange (ETDEWEB)

    Kierkegaard, P.

    1998-10-01

    The project concerning the audio products resulted in energy savings of 90-97% at efficiencies of 91-96% with full effect and stand-by losses of 0.4-3 W. It is especially new epoch-making methods for pulse modulation (called Controlled Oscillation Modulator, COM and Phase Shifted Carrier Pulse Width Modulation, PSCPWM) and error for correction in the effect conversion (called Multivariable Enhanced Cascade Control, MECC and Pulse Edge Delay Error Correction, PEDEC), which has made the breakthrough. Two patents have been applied for, and new digital amplifiers will be introduced in all the relevant products. The project concerning TV products has shown that a loss reduction in deflecting circuits of ca.20 % may be obtained. (EHS)

  8. High Power Performance of Rod Fiber Amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Michieletto, Mattia; Kristensen, Torben;

    2015-01-01

    An improved version of the DMF rod fiber is tested in a high power setup delivering 360W of stable signal power. Multiple testing degrades the fiber and transverse modal instability threshold from >360W to ~290W.......An improved version of the DMF rod fiber is tested in a high power setup delivering 360W of stable signal power. Multiple testing degrades the fiber and transverse modal instability threshold from >360W to ~290W....

  9. Wideband high efficiency CMOS envelope amplifiers for 4G LTE handset envelope tracking RF power amplifiers

    OpenAIRE

    Hassan, Muhammad

    2012-01-01

    Fourth generation cellular networks offer performance similar to cable modems while allowing wide mobility. Although the use of orthogonal frequency division multiplexing in fourth generation increases its spectral efficiency but it also increases the peak-to-average power ratio of the transmitted signal. If a conventional power amplifier is used to transmit a high peak-to-average power ratio signal, then to meet the stringent linearity requirements, it will be operating 6 to 10 dB back-off f...

  10. Phase noise measurement of high-power fiber amplifiers

    Institute of Scientific and Technical Information of China (English)

    Hu Xiao; Xiaolin Wang; Yanxing Ma; Bing He; Pu Zhou; Jun Zhou; Xiaojun Xu

    2011-01-01

    We measure the phase fluctuation in a high-power fiber amplifier using a multi-dithering technique. Its fluctuation property is qualitatively analyzed by the power spectral density and integrated spectral density.Low frequency fluctuations caused by the environment are dominant in the phase fluctuations in an amplifier, whereas the high frequency components related to laser power affect the control bandwidth. The bandwidth requirement of the active phase-locking is calculated to be 300 Hz, 670 Hz, 1.6 kHz, and 3.9 kHz under the output power of 25,55, 125, and 180W, respectively. The approximately linear relationship between the control bandwidth and laser power needs to be further investigated.%@@ We measure the phase fluctuation in a high-power fiber amplifier using a multi-dithering technique.Its fluctuation property is qualitatively analyzed by the power spectral density and integrated spectral density.Low frequency fluctuations caused by the environment are dominant in the phase fluctuations in an am-plifier, whereas the high frequency components related to laser power affect the control bandwidth.The bandwidth requirement of the active phase-locking is calculated to be 300 Hz, 670 Hz, 1.6 kHz, and 3.9kHz under the output power of 25, 55, 125, and 180 W, respectively.The approximately linear relationship between the control bandwidth and laser power needs to be further investigated.

  11. 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.

  12. 5 Watt GaN HEMT Power Amplifier for LTE

    Directory of Open Access Journals (Sweden)

    K. Niotaki

    2014-04-01

    Full Text Available 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 fabricated device is also tested with LTE input signals of different bandwidths (5MHz to 20MHz.

  13. Monolithic Microwave Integrated Circuits (MMIC) Broadband Power Amplifiers (Part 2)

    Science.gov (United States)

    2013-07-01

    2 Figure 2. A 2-GHz load-pull simulation of output power (Pcomp-6 x 65 µm PHEMT). ..............2 Figure 3. A 2-GHz load-pull simulation of PAE (6...5. MMIC 1–5 GHz output power and PAE performance simulation (1, 2, 3, and 4 GHz...load-pull simulation of PAE (6 x 50 µm PHEMT). .......................................7 Figure 9. MMIC 10–19 GHz broadband power amplifier linear

  14. Optical power equalization using Fabry-Perot semiconductor optical amplifier

    Institute of Scientific and Technical Information of China (English)

    Yun Ling; Kun Qiu; Wei Zhang; Ying Pang

    2006-01-01

    A novel scheme of optical power equalization based on Fabry-Perot semiconductor optical amplifier (FPSOA) is proposed. Because of the gain characteristic of FP-SOA, real-time controlling mechanism according to input optical power is aborted in the scheme. The simulations show that 10-dB pulse peak power variation can be clamped in less than i dB. The influences of injecting current, pulse periods, and pulse width are discussed.

  15. Multislice behavioral modeling based on envelope domain for power amplifiers

    Institute of Scientific and Technical Information of China (English)

    Wang Huadong; Bao Jingfu; Wu Zhengde

    2009-01-01

    An envelope domain multislice behavioral modeling is introduced. The tradition AM-AM and AM-PM characteristics of power amplifiers are extended to envelope domain and base-band filter is applied to distortion complex envelope signal for description of the envelope memory effect. Using traditional one and two-tone tests, the coefficients of nonlinear model and the FIR filter can be extracted. At last the model has been applied to a 10 W WCDMA power amplifier to predict its output signal. And simulation results show that the model output conforms very well to the traditional transistor level simulation results.

  16. 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

  17. PHEMT Distributed Power Amplifier Adopting Broadband Impedance Transformer

    DEFF Research Database (Denmark)

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

    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 tran...... 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....

  18. Spatial Power Combining Amplifier for Ground and Flight Applications

    Science.gov (United States)

    Velazco, J. E.; Taylor, M.

    2016-11-01

    Vacuum-tube amplifiers such as klystrons and traveling-wave tubes are the workhorses of high-power microwave radiation generation. At JPL, vacuum tubes are extensively used in ground and flight missions for radar and communications. Vacuum tubes use electron beams as the source of energy to achieve microwave power amplification. Such electron beams operate at high kinetic energies and thus require high voltages to function. In addition, vacuum tubes use compact cavity and waveguide structures that hold very intense radio frequency (RF) fields inside. As the operational frequency is increased, the dimensions of these RF structures become increasingly smaller. As power levels and operational frequencies are increased, the highly intense RF fields inside of the tubes' structures tend to arc and create RF breakdown. In the case of very high-power klystrons, electron interception - also known as body current - can produce thermal runaway of the cavities that could lead to the destruction of the tube. The high voltages needed to power vacuum tubes tend to require complicated and cumbersome power supplies. Consequently, although vacuum tubes provide unmatched high-power microwaves, they tend to arc, suffer from thermal issues, and require failure-prone high-voltage power supplies. In this article, we present a new concept for generating high-power microwaves that we refer to as the Spatial Power Combining Amplifier (SPCA). The SPCA is very compact, requires simpler, lower-voltage power supplies, and uses a unique power-combining scheme wherein power from solid-state amplifiers is coherently combined. It is a two-port amplifier and can be used inline as any conventional two-port amplifier. It can deliver its output power to a coaxial line, a waveguide, a feed, or to any microwave load. A key feature of this new scheme is the use of higher-order-mode microwave structures to spatially divide and combine power. Such higher-order-mode structures have considerably larger cross

  19. High Power Combiner/Divider Design for Dual Band RF Power Amplifiers

    OpenAIRE

    Flattery, Kyle; Amin, Shoaib; Rönnow, Daniel; Mahamat, Yaya; Eroglu, Abdullah

    2015-01-01

    Design of low loss with an enhanced thermal profile power divider/combiner for high power dual-band Radio Frequency (RF) power amplifier applications is given. The practical implementation, low loss and substrate characteristics make this type of combiner ideal for high power microwave applications.  The combiner operational frequencies are chosen to operate at 900 MHz and 2.14 GHz, which are common frequencies for concurrent dual band RF power amplifiers. The analytical results are verified ...

  20. Maximally Flat Waveforms Operation of Class-F Power Amplifiers

    Directory of Open Access Journals (Sweden)

    V. Krizhanovski

    2001-04-01

    Full Text Available The requirements to output network's impedance on higher harmoniccomponents and appropriate input driving for formation maximally flatwaveforms of drain current and voltage were presented. Using suchwaveforms allows obtaining maximal efficiency and output powercapability of class-F power amplifiers.

  1. 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 ...

  2. Analysis of Power Amplifier Modeling Schemes for Crosscorrelation Predistorters

    NARCIS (Netherlands)

    Kokkeler, Andre B.J.

    2004-01-01

    Amplification of signals with fluctuating envelopes leads to distortion because of non-linear behavior of the Power Amplifier (PA). Digital Predistortion can counteract these non-linear effects. A crosscorrelation predistorter is a digital predistorter, based on the calculation of crosscorrelation f

  3. Dynamic deviation Volterra predistorter designed for linearizing power amplifiers

    OpenAIRE

    2011-01-01

    Polynomial models of predistorter combined by the "black box" principle have been considered. A Volterra model using one-dimensional dynamic deviation was proposed. An adaptive predistorter was synthesized for linearizing the Wiener–Hammerstein model of power amplifiers. Estimates of the linearization accuracy and a comparative analysis of predistorter models were also presented.

  4. A 4-9 GHz 10 W wideband power amplifier

    Institute of Scientific and Technical Information of China (English)

    陈中子; 陈晓娟; 姚小江; 袁婷婷; 刘新宇; 李滨

    2009-01-01

    A 4-9 GHz wideband high power amplifier is designed and fabricated, which has demonstrated saturated output power of 10 W covering 6-8 GHz band, and above 6 W over the other band. This PA module uses a bal-ance configuration, and presents power gain of 7.3 ± 0.9 dB over the whole 4-9 GHz band and 39% power-added efficiency (PAE) at 8 GHz. Both the input and output VSWR are also excellent, which are bellow -10 dB.

  5. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment

    OpenAIRE

    Wu Xiao-po; Zhao Hai-yang; Xi Song-tao

    2014-01-01

    Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  6. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment

    Directory of Open Access Journals (Sweden)

    Wu Xiao-po

    2014-06-01

    Full Text Available Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  7. GaN Monolithic Power Amplifiers for Microwave Backhaul Applications

    Directory of Open Access Journals (Sweden)

    Roberto Quaglia

    2016-06-01

    Full Text Available Gallium nitride integrated technology is very promising not only for wireless applications at mobile frequencies (below 6 GHz but also for network backhaul radiolink deployment, now under deep revision for the incoming 5G generation of mobile communications. This contribution presents three linear power amplifiers realized on 0.25 μ m Gallium Nitride on Silicon Carbide monolithic integrated circuits for microwave backhaul applications: two combined power amplifiers working in the backhaul band around 7 GHz, and a more challenging third one working in the higher 15 GHz band. Architectures and main design steps are described, highlighting the pros and cons of Gallium Nitride with respect to the reference technology which, for these applications, is represented by gallium arsenide.

  8. Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization

    Directory of Open Access Journals (Sweden)

    Zhou G Tong

    2007-01-01

    Full Text Available Many modern communication signal formats, such as orthogonal frequency-division multiplexing (OFDM and code-division multiple access (CDMA, have high peak-to-average power ratios (PARs. A signal with a high PAR not only is vulnerable in the presence of nonlinear components such as power amplifiers (PAs, but also leads to low transmission power efficiency. Selected mapping (SLM and clipping are well-known PAR reduction techniques. We propose to combine SLM with threshold clipping and digital baseband predistortion to improve the overall efficiency of the transmission system. Testbed experiments demonstrate the effectiveness of the proposed approach.

  9. Multisine Decomposition Algorithm for RF Power Amplifier Characterization

    DEFF Research Database (Denmark)

    Palmisano, Davide; Galasso, Andrea; Tafuri, Felice Francesco;

    2015-01-01

    This paper presents an algorithm for the generation of a multisine signal capable of accurately mimicking bandwidth and first order statistics such as the probability density function and the peak-to-average power ratio (PAPR) of an arbitrary digitally modulated signal. The implemented algorithm...... outperforms state-of-the-art multisine design procedures by proposing a solution capable of achieving an arbitrarily low PAPR error with respect to the digital signal being decomposed. This innovative step enables a fast multisine-based power amplifier characterization with results that closely match...... that obtained using the actual digital signal....

  10. 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

  11. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by having...... a single local feedback path A (7) with a lowpass characteristic and local forward blocks B¿1? or B (3, 4). The leads to a much improved system with a very low sensitivity to errors in the switching power stage. In the second preferred embodiment of the invention the control structure is extended...... by adding/removing simple local (3) or global (1) forward path blocks. A third embodiment of the invention is a controlled self-oscillating pulse modulator, characterised by first a non-hysteresis comparator as modulator and second by a higher order oscillating loop realised in both forward path B1...

  12. TEDS Base Station Power Amplifier using Low-Noise Envelope Tracking Power Supply

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael A. E.

    2009-01-01

    This paper demonstrates a highly linear and efficient TETRA enhanced data service (TEDS) base-station RF power amplifier (RFPA). Based on the well-known combination of an envelope tracking (ET) power supply and a linear class-A/B RFPA, adequate adjacent channel power ratio (ACPR) and wideband noise...

  13. VDMOS transistors for power amplifier in UHF band

    Science.gov (United States)

    Kassmi, Kamal

    Modeling of power VDMOSFET transistors working in the UHF band is considered. VDMOSFET power structures suited to mobile radiotelephony power amplification are described. A nonlinear physical model suitable for all working regimes is developed. The elements of this model only depend on physical and technological data and bias voltages of the device. A reduced model compatible with SPICE (Simulation Program with Integrated Circuit Emphasis) is presented. A first comparison between measured and computed characteristics is presented under DC switching and small signal conditions. A methodology for the study and design of radio frequency power amplifiers in a nonlinear regime is described. The performance of these devices in terms of power gain, output power, efficiency, linearity and the drain bias influence as well as third order Intermodulation Distortion (IMD3) are considered. It is shown that IMD and power gain performances are controlled by DC output characteristics in the ohmic zone. Practical conclusions with respect to the intrinsic qualities and drawbacks of these products for UHF power amplification are drawn.

  14. Thermal effects in high average power optical parametric amplifiers.

    Science.gov (United States)

    Rothhardt, Jan; Demmler, Stefan; Hädrich, Steffen; Peschel, Thomas; Limpert, Jens; Tünnermann, Andreas

    2013-03-01

    Optical parametric amplifiers (OPAs) have the reputation of being average power scalable due to the instantaneous nature of the parametric process (zero quantum defect). This Letter reveals serious challenges originating from thermal load in the nonlinear crystal caused by absorption. We investigate these thermal effects in high average power OPAs based on beta barium borate. Absorption of both pump and idler waves is identified to contribute significantly to heating of the nonlinear crystal. A temperature increase of up to 148 K with respect to the environment is observed and mechanical tensile stress up to 40 MPa is found, indicating a high risk of crystal fracture under such conditions. By restricting the idler to a wavelength range far from absorption bands and removing the crystal coating we reduce the peak temperature and the resulting temperature gradient significantly. Guidelines for further power scaling of OPAs and other nonlinear devices are given.

  15. X-Parameter Based Modelling of Polar Modulated Power Amplifiers

    DEFF Research Database (Denmark)

    Wang, Yelin; Nielsen, Troels Studsgaard; Sira, Daniel

    2013-01-01

    X-parameters are developed as an extension of S-parameters capable of modelling non-linear devices driven by large signals. They are suitable for devices having only radio frequency (RF) and DC ports. In a polar power amplifier (PA), phase and envelope of the input modulated signal are applied...... at separate ports and the envelope port is neither an RF nor a DC port. As a result, X-parameters may fail to characterise the effect of the envelope port excitation and consequently the polar PA. This study introduces a solution to the problem for a commercial polar PA. In this solution, the RF-phase path...

  16. Possible technical solutions to reduce energy consumption in audio products

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, K.; Andersen, M.A.E.

    1999-07-01

    In common audio products nearly all the supplied power is dissipated as heat. The major consumers are with almost no exception the power supply and the audio amplifier. This paper is divided in two parts, concentrating on typical efficiency measures for the concepts of today and the possibly technical solutions, by which the overall efficiency can be considerably improved in the future. Traditional power supplies are made using a transformer operating on the mains frequency followed by a linear regulator. These are bulky and the efficiency is only around 40%. Using high frequency switch mode power supplies the size of the power supply can be reduced and the efficiency can be increased to 80-90%. Construction of optimal amplifiers in regard to total energy consumption over life time, can only be accomplished by considering both the general volume control distribution, and the general spectral amplitude distribution of audio signals. The traditional efficiency measure specified at the maximum efficiency level says only very little about the real energy consumption of the audio amplifier. As an example, the theoretical efficiency for at traditional class B amplifier is 78%. Using a new efficiency measure defined on the basis of the approximate volume control distribution, an 50W amplifier example shows an overall efficiency of only 1%. In the paper possible solutions and guidelines to increase the real amplifier efficiency are given. (au)

  17. Development of copper bromide laser master oscillator power amplifier system

    Indian Academy of Sciences (India)

    G N Tiwari; R K Mishra; R Khare; S V Nakhe

    2014-02-01

    Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of operating parameters. The electrical input power was varied from 2.6 to 4.3 kW, the pulse repetition frequency (PRF) was changed from 16 to 19 kHz, and the pressure of the buffer gas (neon) was kept fixed at 20 mbar. When the electrical input power was increased to 4.3 kW from 2.6 kW, the tube-wall temperature also increased to 488°C from 426°C but the ratio of the green to yellow power decreased to 1.53 from 3.73. The ratio of green to yellow power decreased to 1.53 from 1.63 when the PRF of the laser was increased to 19 kHz from 16 kHz. These observations are explained in terms of electron temperature, energy levels of transitions, and voltage and current waveforms across the laser head.

  18. High-performance combination method of electric network frequency and phase for audio forgery detection in battery-powered devices.

    Science.gov (United States)

    Savari, Maryam; Abdul Wahab, Ainuddin Wahid; Anuar, Nor Badrul

    2016-09-01

    Audio forgery is any act of tampering, illegal copy and fake quality in the audio in a criminal way. In the last decade, there has been increasing attention to the audio forgery detection due to a significant increase in the number of forge in different type of audio. There are a number of methods for forgery detection, which electric network frequency (ENF) is one of the powerful methods in this area for forgery detection in terms of accuracy. In spite of suitable accuracy of ENF in a majority of plug-in powered devices, the weak accuracy of ENF in audio forgery detection for battery-powered devices, especially in laptop and mobile phone, can be consider as one of the main obstacles of the ENF. To solve the ENF problem in terms of accuracy in battery-powered devices, a combination method of ENF and phase feature is proposed. From experiment conducted, ENF alone give 50% and 60% accuracy for forgery detection in mobile phone and laptop respectively, while the proposed method shows 88% and 92% accuracy respectively, for forgery detection in battery-powered devices. The results lead to higher accuracy for forgery detection with the combination of ENF and phase feature.

  19. High Power Narrow Linewidth 1.26 Micron Ho-Doped Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for the development of an innovative, high power, and extremely reliable 1.26-micron Ho-doped fluoride fiber amplifier. The proposed fiber amplifier...

  20. Time-reversal duality of high-efficiency RF power amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Reveyrand, T; Ramos, I; Popovic, Z

    2012-12-06

    The similarity between RF power amplifiers and rectifiers is discussed. It is shown that the same high-efficiency harmonically-terminated power amplifier can be operated in a dual rectifier mode. Nonlinear simulations with a GaN HEMT transistor model show the time-reversal intrinsic voltage and current waveform relationship between a class-F amplifier and rectifier. Measurements on a class-F-1 amplifier and rectifier at 2.14 GHz demonstrate over 80% efficiency in both cases.

  1. Multi-pass amplifier architecture for high power laser systems

    Science.gov (United States)

    Manes, Kenneth R; Spaeth, Mary L; Erlandson, Alvin C

    2014-04-01

    A main amplifier system includes a first reflector operable to receive input light through a first aperture and direct the input light along an optical path. The input light is characterized by a first polarization. The main amplifier system also includes a first polarizer operable to reflect light characterized by the first polarization state. The main amplifier system further includes a first and second set of amplifier modules. Each of the first and second set of amplifier modules includes an entrance window, a quarter wave plate, a plurality of amplifier slablets arrayed substantially parallel to each other, and an exit window. The main amplifier system additionally includes a set of mirrors operable to reflect light exiting the first set of amplifier modules to enter the second set of amplifier modules and a second polarizer operable to reflect light characterized by a second polarization state.

  2. RF power amplifier: pushing the boundaries of performance versus cost

    Science.gov (United States)

    De Souza, M. M.; Chevaux, N.; Rasheduzzaman, M.

    2012-10-01

    The Radio Frequency Power Amplifier lies at the heart of all modern day communication systems ranging from the cellular infrastructure market to broadcast, radar, medical, automotive and military to name a few. Transmission systems not only require substantial power at high frequencies, but they are also one of the most demanding of semiconductor applications on account of their requirements for efficiency and linearity, which inherently introduces a tradeoff during design. Three types of device technologies have been in typical use for RF power amplification: the VDMOS (at frequencies upto 1 GHz), the LDMOS (at frequencies upto 3.5 GHz), and more recently the Gallium Nitride HEMT, which extends the frequency range upto 5-7 GHz. As an emerging technology, GaN has huge potential, but its widespread use is still currently limited by the level of experience, absence of reliable device models and prices which are roughly (6-10 times that of silicon). This overview highlights the distinct features of the RF Power devices and touches upon the performance metrics of the above technologies (in silicon and GaN).

  3. Cascade Structure of Digital Predistorter for Power Amplifier Linearization

    Directory of Open Access Journals (Sweden)

    E. B. Solovyeva

    2015-12-01

    Full Text Available In this paper, a cascade structure of nonlinear digital predistorter (DPD synthesized by the direct learning adaptive algorithm is represented. DPD is used for linearization of power amplifier (PA characteristic, namely for compensation of PA nonlinear distortion. Blocks of the cascade DPD are described by different models: the functional link artificial neural network (FLANN, the polynomial perceptron network (PPN and the radially pruned Volterra model (RPVM. At synthesis of the cascade DPD there is possibility to overcome the ill conditionality problem due to reducing the dimension of DPD nonlinear operator approximation. Results of compensating nonlinear distortion in Wiener–Hammerstein model of PA at the GSM–signal with four carriers are shown. The highest accuracy of PA linearization is produced by the cascade DPD containing PPN and RPVM.

  4. SiGe HBTs Optimization for Wireless Power Amplifier Applications

    Directory of Open Access Journals (Sweden)

    Pierre-Marie Mans

    2010-01-01

    Full Text Available This paper deals with SiGe HBTs optimization for power amplifier applications dedicated to wireless communications. In this work, we investigate the fT-BVCEO tradeoff by various collector optimization schemes such as epilayer thickness and dopant concentration, and SIC and CAP characteristics. Furthermore, a new trapezoidal base Germanium (Ge profile is proposed. Thanks to this profile, precise control of Ge content at the metallurgical emitter-base junction is obtained. Gain stability is obtained for a wide range of temperatures through tuning the emitter-base junction Ge percent. Finally, a comprehensive investigation of Ge introduction into the collector (backside Ge profile is conducted in order to improve the fT values at high injection levels.

  5. 2.5 GHz integrated graphene RF power amplifier on SiC substrate

    Science.gov (United States)

    Hanna, T.; Deltimple, N.; Khenissa, M. S.; Pallecchi, E.; Happy, H.; Frégonèse, S.

    2017-01-01

    In this work, we report the design of 2.5 GHz integrated power amplifier based on a graphene FET fabricated with thermal deposition on SiC. In this first large signal study of graphene radiofrequency power amplifiers, a power gain of 8.9 dB is achieved, the maximum reported output power and power added efficiency are 5.1 dBm and 2.2% respectively. Furthermore, graphene and Si CMOS amplifiers are compared; conclusions are drawn towards the technology enhancements to optimize the amplifiers figures of merit.

  6. High Efficiency, High Linearity, Switch Mode Power Amplifiers for Varying envelop Signal Applications

    DEFF Research Database (Denmark)

    Tong, Tian; Sira, Daniel; Nielsen, Michael;

    2009-01-01

    using switch-mode power amplifier aided by various linearization techniques can present a feasible way to achieve both high linearity and high power efficiency. In this paper two different implementations of the switch-mode power amplifier a re p resented for varying envelop applications: the RF pulse...

  7. EXPERIMENTAL STUDIES FOR DEVELOPMENT HIGH-POWER AUDIO SPEAKER DEVICES PERFORMANCE USING PERMANENT NdFeB MAGNETS SPECIAL TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Constantin D. STĂNESCU

    2013-05-01

    Full Text Available In this paper the authors shows the research made for improving high-power audio speaker devices performance using permanent NdFeB magnets special technology. Magnetic losses inside these audio devices are due to mechanical system frictions and to thermal effect of Joules eddy currents. In this regard, by special technology, were made conical surfaces at top plate and center pin. Analysing results obtained by modelling the magnetic circuit finite element method using electronic software package,was measured increase efficiency by over 10 %, from 1,136T to13T.

  8. Linearization and efficiency enhancement of power amplifiers using digital predistortion

    Energy Technology Data Exchange (ETDEWEB)

    Safari, Nima

    2008-07-01

    Today, demand of higher spectral efficiency forces wireless communication systems to employ non-constant envelope modulation schemes such as Quadrature Amplitude Modulations (QAM), Code Division Multiple Access (CDMA) and Orthogonal Frequency-Division Multiplexing (OFDM) schemes. These modulation techniques generate signals with wide range of envelope fluctuation. This property makes these schemes sensitive to nonlinear amplifications. Nonlinearities introduced by Power Amplifiers (PA) cause both a distortion of the signal and an increased out of band output spectrum, which leads to a rise in adjacent channel interference. Thus, in order to ensure a high spectral efficiency and to avoid spectral regrowth, a linearization technique is required. Among all the linearization techniques, basedband Digital Predistortion (DPD) is one of the commonly used linearization techniques, which is characterized by robust operation, low implementation cost and high accuracy. In the first chapter of this thesis, an introduction on the motivation and necessity of using PA linearization techniques is presented. Digital Predistortion as a popular linearization technique aims to improve the efficiency and linearity of RF power amplifiers. The scope of the thesis, the goals to be achieved and the contributions are also discussed in chapter one. Chapter two, mainly discusses sample-by-sample updating algorithm in Digital Predistorters to adaptively linearize the PA memoryless nonlinearities. Look-up Table (LUT) and polynomial approaches are studied and implemented in Hardware using a test-bed provided by Nera Research. The experimental results together with a discussion are then given. A new DPD algorithm based on block estimation is proposed in chapter three to avoid realtime signal processing, reduce the complexity and also avoid the bad performance during the slow adaptation of adaptive the Adjacent Channel Power Ratio (ACPR) and the Error Vector Magnitude (EVM) requirements. In

  9. Power scaling of supercontinuum seeded megahertz-repetition rate optical parametric chirped pulse amplifiers.

    Science.gov (United States)

    Riedel, R; Stephanides, A; Prandolini, M J; Gronloh, B; Jungbluth, B; Mans, T; Tavella, F

    2014-03-15

    Optical parametric chirped-pulse amplifiers with high average power are possible with novel high-power Yb:YAG amplifiers with kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier with 11.4 W average power with 20.7% pump-to-signal conversion efficiency. For parametric amplification, a beta-barium borate crystal is pumped by a 140 W, 1 ps Yb:YAG InnoSlab amplifier at 3.25 MHz repetition rate. The broadband seed is generated via supercontinuum generation in a YAG crystal.

  10. 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

  11. A C-band GaN based linear power amplifier with 55.7% PAE

    Science.gov (United States)

    Luo, Weijun; Chen, Xiaojuan; Zhang, Hui; Liu, Guoguo; Zheng, Yingkui; Liu, Xinyu

    2010-04-01

    A C-band linear power amplifier is successfully developed with a one-chip 2 mm AlGaN/GaN high electron mobility transistors (HEMTs). Two kinds of matching circuits for the linear power amplifier are compared. Besides, stabilization methods for the amplifier are also discussed. At 5.4 GHz, the developed GaN HEMTs linear power amplifier delivers a 37.2 dBm (5.2 W) cw P1 dB output power with 9 dB linear gain and 55.7% maximum power-added efficiency (PAE) with a drain voltage of 25 V. To our best knowledge, the achieved PAE is the state-of-the-art result ever reported for 2 mm gate width single die GaN-based hybrid microwave integrated power amplifier at C-band.

  12. On the power amplifier nonlinearity in MIMO transmit beamforming systems

    KAUST Repository

    Qi, Jian

    2012-03-01

    In this paper, single-carrier multiple-input multiple-output (MIMO) transmit beamforming (TB) systems in the presence of high-power amplifier (HPA) nonlinearity are investigated. Specifically, due to the suboptimality of the conventional maximal ratio transmission/maximal ratio combining (MRT/MRC) under HPA nonlinearity, we propose the optimal TB scheme with the optimal beamforming weight vector and combining vector, for MIMO systems with nonlinear HPAs. Moreover, an alternative suboptimal but much simpler TB scheme, namely, quantized equal gain transmission (QEGT), is proposed. The latter profits from the property that the elements of the beamforming weight vector have the same constant modulus. The performance of the proposed optimal TB scheme and QEGT/MRC technique in the presence of the HPA nonlinearity is evaluated in terms of the average symbol error probability and mutual information with the Gaussian input, considering the transmission over uncorrelated quasi-static frequency-flat Rayleigh fading channels. Numerical results are provided and show the effects on the performance of several system parameters, namely, the HPA parameters, numbers of antennas, quadrature amplitude modulation modulation order, number of pilot symbols, and cardinality of the beamforming weight vector codebook for QEGT. © 2012 IEEE.

  13. NONLINEAR CHARACTERIZATION OF CONCURRENT DUAL-BAND RF POWER AMPLIFIERS

    Institute of Scientific and Technical Information of China (English)

    Hui Ming; Liu Taijun; Ye Yan; Zhang Haili; Shen Dongya; Li Liang

    2012-01-01

    In this paper,the synchronous concurrent dual-band RF signal is used to drive the RF Power Amplifier (PA).The nonlinear characterization of a concurrent dual-band RF PA is discussed while two band signals in the dual-band are modulated by CDMA2000 and WCDMA signals.When the two band signals in the dual-band of the PA are modulated with the same signals,it is found that the nonlinearity of the PA can be expressed by any of the two corresponding baseband data.On the other hand,when the two band signals in the dual-band of the PA are modulated with two different signals,the PA nonlinearity cannot be characterized by any of the two corresponding baseband data.In this case,its nonlinearity has to be denoted by a composite signals consisting of the two baseband signals.Consequently,the requirements for the speed of the A/D converter can be largely reduced.The experimental results with CDMA2000 and WCDMA signals demonstrate the speed of the A/D converter required is only 30 M Sample Per Second (SaPS),but it will be at least 70 M SaPS for the conventional method.

  14. A heterogeneous multiprocessor architecture for low-power audio signal processing applications

    DEFF Research Database (Denmark)

    Paker, Ozgun; Sparsø, Jens; Haandbæk, Niels;

    2001-01-01

    . The processors are tailored for different classes of filtering algorithms (FIR, IIR, N-LMS etc.), and in a typical system the communication among processors occurs at the sampling rate only. The processors are parameterized in word-size, memory-size, etc. and can be instantiated according to the needs...... of the application at hand using a normal synthesis based ASIC design flow. To give an impression of the size of a processor we mention that one of the FIR processors in a prototype design has 16 instructions, a 32 word×16 bit program memory, a 64 word×16 bit data memory and a 25 word×16 bit coefficient memory....... Early results obtained from the design of a prototype chip containing filter processors for a hearing aid application, indicate a power consumption that is an order of magnitude better than current state of the art low-power audio DSPs implemented using full-custom techniques. This is due to: (1...

  15. Power amplifier for 1064 nm using Yb3+-doped double-clad fiber

    Institute of Scientific and Technical Information of China (English)

    Lingfeng Kong(孔令峰); Qihong Lou(楼祺洪); Jun Zhou(周军); Zhonglin Wu(吴中林); Jingxing Dong(董景星); Yunrong Wei(魏运荣); Jianqiang Zhu(朱健强)

    2004-01-01

    @@ A master-oscillator fiber power amplifier(MOPA)system is presented,which consists of a single modelaser as the master oscillator and an Yba+-doped large-mode-area double-clad fiber as the power amplifier.The system emits up to 6 W of amplified radiation at a wavelength of 1064 nm.The slope efficiency andextracted pulse energy as a function of pulse repetition rate are analyzed.

  16. An RF-input outphasing power amplifier with RF signal decomposition network

    OpenAIRE

    Barton, Taylor W.; Perreault, David J.

    2015-01-01

    This work presents an outphasing power amplifier that directly amplifies a modulated RF input. The approach eliminates the need for multiple costly IQ modulators and baseband signal component separation found in conventional outphasing power amplifier systems, which have previously required both an RF carrier input and a separate baseband input to synthesize a modulated RF output. A novel RF signal decomposition network enables direct RF-input / RF-output outphasing by directly synthesizing t...

  17. GaN MMIC Power Amplifiers for S-band and X-band

    NARCIS (Netherlands)

    Suijker, E.M.; Sudow, M.; Fagerlind, M.; Hek, A.P. de; Vliet, F.E. van; Rorsman, N.

    2008-01-01

    The development of two GaN MMIC power amplifiers is reported. The amplifiers are processed in the AlGaN/GaN technology of Chalmers University of Technology using 0.25 μm HEMTs. The S-band amplifier operates at frequencies from 3 to 4 GHz and has a maximum output power of 5.6 W with an associated eff

  18. A 24 channel acoustic/vibration test power amplifier

    Science.gov (United States)

    Barlett, F. R.

    1978-01-01

    In the present paper, the advantages and drawbacks of a multichannel amplifier operating in a vibration or acoustic facility are discussed. The configuration of the facility and the multichannel amplifier proposed is a compromise based on the particular requirements and anticipated work load in a specific case under consideration.

  19. L-band AlGaN/GaN Power Amplifier with Protection Against Load Mismatch

    NARCIS (Netherlands)

    Heijningen, M. van; Bent, G. van der; Houwen, E.H. van der; Chowdhary, A.; 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

  20. Design of Wireless Power Transfer System Using E-class Amplifier

    Science.gov (United States)

    Zhang, Le; Zhang, Yuan; Zhu, Wu; Huang, Jing

    2016-05-01

    This paper mainly discuss the wireless power transfer system based on class-E amplifier. Firstly, the system coupling model was established and the working principle and parameter design of class-E amplifier was analyzed in detail. Then proposed a method of high frequency driver design using high frequency power transistor push-pull mode. On this basis, we successfully designed and built the wireless power transfer system. The maximum transmission power is 15W and the transmission distance is 20cm. The method of class-E amplifier is verified in wireless power transfer system.

  1. Microwave dynamic large signal waveform characterization of advanced InGaP HBT for power amplifiers

    Institute of Scientific and Technical Information of China (English)

    Zhao Lixin; Jin Zhi; Liu Xinyu

    2009-01-01

    In wireless mobile communications and wireless local area networks (WLAN), advanced lnGaP HBT with power amplifiers are key components. In this paper, the microwave large signal dynamic waveform characteristics of an advanced InGaP HBT are investigated experimentally for 5.8 GHz power amplifier applications. The microwave large signal waveform distortions at various input power levels, especially at large signal level, are investigated and the reasons are analyzed. The output power saturation is also explained. These analyses will be useful for power amplifier designs.

  2. A High Dynamic Range and Low Power Consumption Audio Delta-Sigma Modulator with Opamp Sharing Technique among Three Integrators

    Science.gov (United States)

    Kanemoto, Daisuke; Ido, Toru; Taniguchi, Kenji

    A low power and high performance with third order delta-sigma modulator for audio applications, fabricated in a 0.18µm CMOS process, is presented. The modulator utilizes a third order noise shaping with only one opamp by using an opamp sharing technique. The opamp sharing among three integrator stages is achieved through the optimal operation timing, which makes use of the load capacitance differences between the three integrator stages. The designed modulator achieves 101.1dB signal-to-noise ratio (A-weighted) and 101.5dB dynamic range (A-weighted) with 7.5mW power consumption from a 3.3V supply. The die area is 1.27mm2. The fabricated delta-sigma modulator achieves the highest figure-of-merit among published high performance low power audio delta-sigma modulators.

  3. W-band Solid State Power Amplifier for Remote Sensing Radars Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High power, compact, reliable and affordable power amplifiers operating in the W-band (94 GHz region) are critical to realizing transmitters for many NASA missions...

  4. MMIC for High-Efficiency Ka-BAnd GaN Power Amplifiers (2007043) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the need for high-efficiency, high-output power amplifiers operating in the Ka-band frequencies. For space communications, the power...

  5. Diode-Pumped High Energy and High Average Power All-Solid-State Picosecond Amplifier Systems

    OpenAIRE

    Jiaxing Liu; Wei Wang; Zhaohua Wang; Zhiguo Lv; Zhiyuan Zhang; Zhiyi Wei

    2015-01-01

    We present our research on the high energy picosecond laser operating at a repetition rate of 1 kHz and the high average power picosecond laser running at 100 kHz based on bulk Nd-doped crystals. With diode-pumped solid state (DPSS) hybrid amplifiers consisting of a picosecond oscillator, a regenerative amplifier, end-pumped single-pass amplifiers, and a side-pumped amplifier, an output energy of 64.8 mJ at a repetition rate of 1 kHz was achieved. An average power of 37.5 W at a repetition ra...

  6. Empirical multichannel power consumption model for erbium-doped fiber amplifiers

    DEFF Research Database (Denmark)

    Saldaña Cercos, Silvia; de Paiva, Getulio E. R.; Argentato, Marcio Colazza;

    2015-01-01

    simultaneously contributes significantly, up to 48%, to the total power consumption due to the circuitry used for controlling the EDFA. As the number of simultaneous amplified WDM channels in high capacity long and medium reach transmission links reflects closely traffic patterns generated by end......In this paper we report on the first experimental power consumption analysis and model of single and multi-stage booster erbium-doped fiber amplifiers (EDFAs) with automatic gain control (AGC), accounting for channel number dependency. Results show that the amount of channels being amplified......-users, it is relevant to study channel number dependent power consumption for devising EDFA power efficient control and design....

  7. The Simulation Analysis of Nonlinear for a Power Amplifier with Memory Effects

    Directory of Open Access Journals (Sweden)

    Lv. Jinqiu

    2014-09-01

    Full Text Available For the nonlinear distortion problem of current power amplifiers (PAs with memory effects, we use goal programming to present a memoryless predistorter matrix model based on limiting baseband predistortion technique, and the normalized mean squared error (NMSE is limited in a satisfactory range while the output power is maximum. Then we propose a nonlinear power amplifier with memory effects based on back propagation neural network (BPNN with three tapped delay nodes and six single hidden layer nodes, which is single input - dual output. Simulation results show that the method proposed in this paper makes the experimental precision higher. Further, the linearization effect of power amplifiers becomes better.

  8. Audio Papers

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh; Samson, Kristine

    2016-01-01

    With this special issue of Seismograf we are happy to present a new format of articles: Audio Papers. Audio papers resemble the regular essay or the academic text in that they deal with a certain topic of interest, but presented in the form of an audio production. The audio paper is an extension...

  9. Diode-Pumped High Energy and High Average Power All-Solid-State Picosecond Amplifier Systems

    Directory of Open Access Journals (Sweden)

    Jiaxing Liu

    2015-12-01

    Full Text Available We present our research on the high energy picosecond laser operating at a repetition rate of 1 kHz and the high average power picosecond laser running at 100 kHz based on bulk Nd-doped crystals. With diode-pumped solid state (DPSS hybrid amplifiers consisting of a picosecond oscillator, a regenerative amplifier, end-pumped single-pass amplifiers, and a side-pumped amplifier, an output energy of 64.8 mJ at a repetition rate of 1 kHz was achieved. An average power of 37.5 W at a repetition rate of 100 kHz pumped by continuous wave laser diodes was obtained. Compact, stable and high power DPSS laser amplifier systems with good beam qualities are excellent picosecond sources for high power optical parametric chirped pulse amplification (OPCPA and high-efficiency laser processing.

  10. A high efficiency C-band internally-matched harmonic tuning GaN power amplifier

    Science.gov (United States)

    Lu, Y.; Zhao, B. C.; Zheng, J. X.; Zhang, H. S.; Zheng, X. F.; Ma, X. H.; Hao, Y.; Ma, P. J.

    2016-09-01

    In this paper, a high efficiency C-band gallium nitride (GaN) internally-matched power amplifier (PA) is presented. This amplifier consists of 2-chips of self-developed GaN high-electron mobility transistors (HEMTs) with 16 mm total gate width on SiC substrate. New harmonic manipulation circuits are induced both in the input and output matching networks for high efficiency matching at fundamental and 2nd-harmonic frequency, respectively. The developed amplifier has achieved 72.1% power added efficiency (PAE) with 107.4 W output power at 5 GHz. To the best of our knowledge, this amplifier exhibits the highest PAE in C-band GaN HEMT amplifiers with over 100 W output power. Additionally, 1000 hours' aging test reveals high reliability for practical applications.

  11. FPGA-Based Digital Current Switching Power Amplifiers Used in Magnetic Bearing Systems

    Science.gov (United States)

    Wang, Yin; Zhang, Kai; Dong, Jinping

    For a traditional two-level current switching power amplifier (PA) used in a magnetic bearing system, its current ripple is obvious. To increase its current ripple performance, three-level amplifiers are designed and their current control is generally based on analog and logical circuits. So the required hardware is complex and a performance increase from the hardware adjustment is difficult. To solve this problem, a FPGA-based digital current switching power amplifier (DCSPA) was designed. Its current ripple was obviously smaller than a two-level amplifier and its control circuit was much simpler than a tri-level amplifier with an analog control circuit. Because of the field-programmable capability of a FPGA chip used, different control algorithms including complex nonlinear algorithms could be easily implemented in the amplifier and their effects could be compared with the same hardware.

  12. Power neodymium-glass amplifier of a repetitively pulsed laser

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, Aleksandr V; Gaganov, V E; Garanin, Sergey G; Zhidkov, N V; Krotov, V A; Martynenko, S P; Pozdnyakov, E V; Solomatin, I I [Russian Federal Nuclear Center ' All-Russian Research Institute of Experimental Physics' , Sarov, Nizhnii Novgorod region (Russian Federation)

    2011-11-30

    A neodymium-glass diode-pumped amplifier with a zigzag laser beam propagation through the active medium was elaborated; the amplifier is intended for operation in a repetitively pulsed laser. An amplifier unit with an aperture of 20 Multiplication-Sign 25 mm and a {approx}40-cm long active medium was put to a test. The energy of pump radiation amounts to 140 J at a wavelength of 806 nm for a pump duration of 550 {mu}s. The energy parameters of the amplifier were experimentally determined: the small-signal gain per pass {approx}3.2, the linear gain {approx}0.031 cm{sup -1} with a nonuniformity of its distribution over the aperture within 15%, the stored energy of 0.16 - 0.21 J cm{sup -3}. The wavefront distortions in the zigzag laser-beam propagation through the active element of the amplifier did not exceed 0.4{lambda} ({lambda} = 0.63 {mu}m is the probing radiation wavelength).

  13. Peak power tunable mid-infrared oscillator pumped by a high power picosecond pulsed fiber amplifier with bunch output

    Science.gov (United States)

    Wei, Kaihua; Guo, Yan; Lai, Xiaomin; Fan, Shanhui

    2016-07-01

    A high power mid-infrared optical parametric oscillator (OPO) with picosecond pulse bunch output is experimentally demonstrated. The pump source was a high power master oscillation power amplifier (MOPA) picosecond pulsed fiber amplifier. The seed of the MOPA was a gain-switched distributed Bragg reflector (DBR) laser diode (LD) with picosecond pulse operation at a high repetition rate. The seed laser was amplified to 50 W by two-stage pre-amplifiers and a large mode area (LMA) Yb fiber based power-amplifier. A fiber-pigtailed acousto-optic modulator with the first order diffraction transmission was inserted into the second pre-amplifier to form a picosecond pulse bunch train and to change the peak power simultaneously. The power-amplified pulse bunches were focused to pump a wavelength-tunable OPO for emitting high power mid-infrared laser. By adjusting the OPO cavity length, the maximum average idler powers obtained at 3.1, 3.3 and 3.5 μm were 7, 6.6 and 6.4 W respectively.

  14. High Efficiency Ka-Band Solid State Power Amplifier Waveguide Power Combiner

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.; Chevalier, Christine T.; Freeman, Jon C.

    2010-01-01

    A novel Ka-band high efficiency asymmetric waveguide four-port combiner for coherent combining of two Monolithic Microwave Integrated Circuit (MMIC) Solid State Power Amplifiers (SSPAs) having unequal outputs has been successfully designed, fabricated and characterized over the NASA deep space frequency band from 31.8 to 32.3 GHz. The measured combiner efficiency is greater than 90 percent, the return loss greater than 18 dB and input port isolation greater than 22 dB. The manufactured combiner was designed for an input power ratio of 2:1 but can be custom designed for any arbitrary power ratio. Applications considered are NASA s space communications systems needing 6 to 10 W of radio frequency (RF) power. This Technical Memorandum (TM) is an expanded version of the article recently published in Institute of Engineering and Technology (IET) Electronics Letters.

  15. High power pulse amplification of ytterbium-doped double-clad fiber amplifier

    Institute of Scientific and Technical Information of China (English)

    Liping Chang; Wei Fan; Jialin Chen; Li Wang; Bai Chen; Zunqi Lin

    2007-01-01

    By solving a set of time-dependent equations, the characteristics of the ytterbium-doped double-clad fiber amplifier are presented. Besides the steady state in the fiber of the upper-state population, pump power and amplified spontaneous emission without the input signal, the dynamic characteristics of the high power Gaussian pulse amplification like the evolution of pulse waveform distortion, upper-state population distribution and stored energy and pulse energy of the amplifier under the forward and backward pump,are simulated. The relations between the output pulse energy of the amplifier and the different input pulse peak power or pump power are also discussed. The models and results can provide important guide for the design and optimization of the high power pulse amplification.

  16. X-band inverse class-F GaN internally-matched power amplifier

    Science.gov (United States)

    Zhao, Bo-Chao; Lu, Yang; Han, Wen-Zhe; Zheng, Jia-Xin; Zhang, Heng-Shuang; Ma, Pei-jun; Ma, Xiao-Hua; Hao, Yue

    2016-09-01

    An X-band inverse class-F power amplifier is realized by a 1-mm AlGaN/GaN high electron mobility transistor (HEMT). The intrinsic and parasitic components inside the transistor, especially output capacitor Cds, influence the harmonic impedance heavily at the X-band, so compensation design is used for meeting the harmonic condition of inverse class-F on the current source plane. Experiment results show that, in the continuous-wave mode, the power amplifier achieves 61.7% power added efficiency (PAE), which is 16.3% higher than the class-AB power amplifier realized by the same kind of HEMT. To the best of our knowledge, this is the first inverse class-F GaN internally-matched power amplifier, and the PAE is quite high at the X-band. Project supported by the National High Technology Research and Development Program of China (Grant No. 2015AA016801).

  17. Design of an S-band power combiner system with two parallel power amplifiers and phase shifters

    OpenAIRE

    Özbey, Burak

    2011-01-01

    Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Science of Bilkent University, 2011. Thesis (Master's) -- Bilkent University, 2011. Includes bibliographical references leaves 70-72. RF power amplifiers are important blocks in a wireless communication system that play a vital role in determining the level of overall performance. In some situations, more power than a single power amplifier can alone provide is required in...

  18. Impact of gain saturation on the mode instability threshold in high-power fiber amplifiers

    DEFF Research Database (Denmark)

    Hansen, Kristian Rymann; Lægsgaard, Jesper

    2014-01-01

    We present a coupled-mode model of transverse mode instability in high-power fiber amplifiers, which takes the effect of gain saturation into account. The model provides simple semi-analytical formulas for the mode instability threshold, which are valid also for highly saturated amplifiers...

  19. Ka-Band AlGaN/GaN HEMT high power and driver amplifier MMICs

    NARCIS (Netherlands)

    Heijningen, M. van; Vliet, F.E. van; Quay, R.; Raay, F. van; Kiefer, R.; Mueller, S.; Krausse, D.; Seelmann-Eggebert, M.; Mikulla, M.; Schlechtweg, M.

    2005-01-01

    In this paper the MMIC technology, design and characterization of a high power amplifier and driver amplifier MMIC at 30 GHz in AlGaN/GaN HEMT technology are presented. The MMICs are designed using CPW technology on a 390 μm thick SiC substrate. The measured small-signal gain of the driver is 14 dB

  20. Small sized high-gain PHEMT high-power amplifiers for X-band applications

    NARCIS (Netherlands)

    Hek, A.P. de; Hunneman, P.A.H.

    2000-01-01

    The development of two small sized broadband X-band high-power amplifiers is discussed. The amplifiers are realised with the help of the pseudomorphic HEMT technology of the Fraunhofer Institute for Applied Solid State Physics (FhG-IAF). With the help of this technology the feasibility of integratin

  1. An X-band four-way combined GaN solid-state power amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Chen Chi; Hao Yue; Feng Hui; Gu Wenping; Li Zhiming; Hu Shigang; Ma Teng, E-mail: ccachi@163.co [National Key Laboratory of Wide Band-Gap Semiconductor Technology, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-01-15

    An X-band four-way combined GaN solid-state power amplifier module is fabricated based on a self-developed AlGaN/GaN HEMT with 2.5-mm gate width technology on SiC substrate. The module consists of an AlGaN/GaN HEMT, Wilkinson power hybrids, a DC-bias circuit and microstrip matching circuits. For the stability of the amplifier module, special RC networks at the input and output, a resistor between the DC power supply and a transistor gate at the input and 3{lambda}/4 Wilkinson power hybrids are used for the cancellation of low frequency self-oscillation and crosstalk of each amplifier. Under V{sup ds} = 27 V, V{sup gs} = -4.0 V, CW operating conditions at 8 GHz, the amplifier module exhibits a line gain of 5 dB with a power added efficiency of 17.9%, and an output power of 42.93 dBm; the power gain compression is 2 dB. For a four-way combined solid-state amplifier, the power combining efficiency is 67.5%. It is concluded that the reduction in combining efficiency results from the non-identical GaN HMET, the loss of the hybrid coupler and the circuit fabricating errors of each one-way amplifier. (semiconductor integrated circuits)

  2. A compact high efficiency 8 kW 325 MHz power amplifier for accelerator applications

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Jitendra Kumar, E-mail: jkmishra@barc.gov.in; Ramarao, B.V.; Pande, Manjiri M.; Singh, P.

    2014-11-11

    A solid state RF power amplifier (SSRFPA) has been designed and developed for 8 kW RF power at 325 MHz. The work was carried out to achieve high efficiency (over 70% efficiency), high gain and compact size for the amplifier module. The sub-components of this amplifier like a 1 kW amplifier module at 325 MHz, an 8-way RF power combiner rated for 8 kW RF power and a micro-strip based power divider have been designed and developed in-house. The size of the amplifier is miniaturized by incorporating innovative design techniques and proper selection of the substrate material in the input/output matching networks. Measured power gain and conversion efficiency of the solid state RF power amplifier module at 1.06 kW output is 21.7 dB and 73.2%, respectively. A coaxial line based 8-way Wilkinson power combiner has been designed and developed. Return loss of the combiner at the output (combined) port is 26.4 dB at 325 MHz. Transmission parameters of the combiner from each input (splitting) port to output port are 9.1 dB±0.15 dB. This amplifier uses a pre-driver of 20 W and a driver amplifier of 150 W. Total power gain and efficiency of 8 kW SSRFPA have been 92.3 dB (including the driver stages) and 68.3%, respectively. The harmonic content in the RF output is less than −50 dBc for all the harmonics. Main features of this development are high power density (kW/cm{sup 3}), large value for kW/module, high efficiency (68.3%) for 8 kW SSRFPA at 325 MHz and rugged operation.

  3. A compact high efficiency 8 kW 325 MHz power amplifier for accelerator applications

    Science.gov (United States)

    Mishra, Jitendra Kumar; Ramarao, B. V.; Pande, Manjiri M.; Singh, P.

    2014-11-01

    A solid state RF power amplifier (SSRFPA) has been designed and developed for 8 kW RF power at 325 MHz. The work was carried out to achieve high efficiency (over 70% efficiency), high gain and compact size for the amplifier module. The sub-components of this amplifier like a 1 kW amplifier module at 325 MHz, an 8-way RF power combiner rated for 8 kW RF power and a micro-strip based power divider have been designed and developed in-house. The size of the amplifier is miniaturized by incorporating innovative design techniques and proper selection of the substrate material in the input/output matching networks. Measured power gain and conversion efficiency of the solid state RF power amplifier module at 1.06 kW output is 21.7 dB and 73.2%, respectively. A coaxial line based 8-way Wilkinson power combiner has been designed and developed. Return loss of the combiner at the output (combined) port is 26.4 dB at 325 MHz. Transmission parameters of the combiner from each input (splitting) port to output port are 9.1 dB±0.15 dB. This amplifier uses a pre-driver of 20 W and a driver amplifier of 150 W. Total power gain and efficiency of 8 kW SSRFPA have been 92.3 dB (including the driver stages) and 68.3%, respectively. The harmonic content in the RF output is less than -50 dBc for all the harmonics. Main features of this development are high power density (kW/cm3), large value for kW/module, high efficiency (68.3%) for 8 kW SSRFPA at 325 MHz and rugged operation.

  4. A compact 500 MHz 4 kW Solid-State Power Amplifier for accelerator applications

    Science.gov (United States)

    Gaspar, M.; Pedrozzi, M.; Ferreira, L. F. R.; Garvey, T.

    2011-05-01

    We present the development of a compact narrow-band Solid-State Power Amplifier (SSPA). We foresee a promising application of solid-state amplifiers specifically in accelerators for new generation synchrotron light sources. Such a new technology has reached a competitive price/performance ratio and expected lifetime in comparison with klystron and IOT amplifiers. The increasing number of synchrotron light sources using 500 MHz as base frequency justifies the effort in the development of the proposed amplifier. Two different techniques are also proposed to improve the control and performance of these new distributed amplification systems which we call, respectively, complete distributed system and forced compression.

  5. Low-timing-jitter high-power mode-locked 1063 nm Nd:GdVO₄ master oscillator power amplifier.

    Science.gov (United States)

    Wang, Zhi-min; Zhang, Feng-feng; Zuo, Jun-wei; Yang, Jing; Yuan, Lei; Peng, Qin-jun; Cui, Da-fu; Xu, Zu-yan

    2015-10-01

    A low-timing-jitter high-power semiconductor saturable absorber mirror mode-locked picosecond (ps) 1063 nm Nd:GdVO4 master oscillator power amplifier is presented. Using a single-pass Nd:GdVO4 amplifier, an amplified laser with 21.5 W output power and 8.3 ps pulsewidth was achieved at 250 MHz repetition rate. Employing a servo control, an average RMS timing jitter of ∼222  fs was realized. This laser can be used as a drive laser for photocathode injectors in free-electron lasers.

  6. A programmable log-linear amplifier for wide range nuclear power measuring channels

    Science.gov (United States)

    Khaleeq, M. Tahir; Alam, Mahmood; Ghumman, Iftikhar Ahmad

    2002-12-01

    A programmable log-linear amplifier has been developed for nuclear channels. The amplifier can be programmed for logarithmic, linear or log-linear mode of operation. In the log-linear mode, the amplifier operates partially in log mode and automatically switches to linear mode at any preset point. The log-linear mode is used for wide range operation of nuclear channels and, hence, the amplifier will improve the fault finding capabilities of the nuclear channels used in power range. The amplifier is tested at nuclear reactor and the results are found in very good agreement with the designed specifications. This article presents design and construction of the amplifier and field test results.

  7. High Performance Ka Band Power Amplifiers for Future EVA Radio Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, AlphaSense, Inc. and the University of Washington detail the development of a novel, high performance Ka band power amplifier for EVA radio...

  8. Heterojunction Bipolar Transistor Power Amplifiers for Long-Range X-band Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR Phase I project, Vega Wave Systems, Inc. will develop and demonstrate a novel InGaP-GaAs heterojunction bipolar transistor power amplifier for...

  9. Optimized Pump Power Ratio on 2nd Order Pumping Discrete Raman Amplifier

    Institute of Scientific and Technical Information of China (English)

    Renxiang; Huang; Youichi; Akasaka; David; L.; Harris; James; Pan

    2003-01-01

    By optimizing pump power ratio between 1st order backward pump and 2nd order forward pump on discrete Raman amplifier, we demonstrated over 2dB noise figure improvement without excessive non-linearity degradation.

  10. High-average-power and high-beam-quality Innoslab picosecond laser amplifier.

    Science.gov (United States)

    Xu, Liu; Zhang, Hengli; Mao, Yefei; Yan, Ying; Fan, Zhongwei; Xin, Jianguo

    2012-09-20

    We demonstrated a laser-diode, end-pumped picosecond amplifier. With effective shaping of the seed laser, we achieved 73 W amplified laser output at the pump power of 255 W, and the optical-optical efficiency was about 28%. The beam propagation factors M(2) measured at the output power of 60 W in the horizontal direction and the vertical direction were 1.5 and 1.4, respectively.

  11. Gain and noise penalty for detuned 980 nm pumping or erbium-doped fiber power amplifiers

    DEFF Research Database (Denmark)

    Pedersen, B.; Chirravuri, J.; Miniscalco, W. J.

    1992-01-01

    The impact of altering the fiber length and pump wavelength on the gain and noise performance of erbium-doped fiber power amplifiers pumped in the 980-nm band is examined. A gain penalty of......The impact of altering the fiber length and pump wavelength on the gain and noise performance of erbium-doped fiber power amplifiers pumped in the 980-nm band is examined. A gain penalty of...

  12. Power amplifiers for the S-, C-, X- and Ku-bands an EDA perspective

    CERN Document Server

    Božanić, Mladen

    2016-01-01

    This book provides a detailed review of power amplifiers, including classes and topologies rarely covered in books, and supplies sufficient information to allow the reader to design an entire amplifier system, and not just the power amplification stage. A central aim is to furnish readers with ideas on how to simplify the design process for a preferred power amplifier stage by introducing software-based routines in a programming language of their choice. The book is in two parts, the first focusing on power amplifier theory and the second on EDA concepts. Readers will gain enough knowledge of RF and microwave transmission theory, principles of active and passive device design and manufacturing, and power amplifier design concepts to allow them to quickly create their own programs, which will help to accelerate the transceiver design process. All circuit designers facing the challenge of designing an RF or microwave power amplifier for frequencies from 2 to 18 GHz will find this book to be a valuable asset.

  13. A describing function approach to bipolar RF-power amplifier simulation

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    1981-01-01

    A method for fast and accurate computations of the primary performance parameters such as gain, efficiency, output power, and bandwidth in class-C biased RF-power amplifier stages is presented. The method is based on a describing function characterization of the RF-power transistor where the term...

  14. CMOS 60-GHz and E-band power amplifiers and transmitters

    CERN Document Server

    Zhao, Dixian

    2015-01-01

    This book focuses on the development of design techniques and methodologies for 60-GHz and E-band power amplifiers and transmitters at device, circuit and layout levels. The authors show the recent development of millimeter-wave design techniques, especially of power amplifiers and transmitters, and presents novel design concepts, such as “power transistor layout” and “4-way parallel-series power combiner”, that can enhance the output power and efficiency of power amplifiers in a compact silicon area. Five state-of-the-art 60-GHz and E-band designs with measured results are demonstrated to prove the effectiveness of the design concepts and hands-on methodologies presented. This book serves as a valuable reference for circuit designers to develop millimeter-wave building blocks for future 5G applications.

  15. High-power near-diffraction-limited solid-state amplified spontaneous emission laser devices.

    Science.gov (United States)

    Smith, G; Shardlow, P C; Damzen, M J

    2007-07-01

    We present investigations into high-power scaling of solid-state amplified spontaneous emission (ASE) laser sources by use of two high-gain (~10(4)) Nd:YVO(4) bounce amplifiers. The sources deliver high power with a high-quality spatial output, but unlike a laser they have a high misalignment tolerance and do not require a precisely aligned cavity. In one system with two amplifiers, we demonstrate an ASE source with 24.5W of output power with good spatial quality, M(2)vertical. In a more sophisticated setup, the two amplifiers are arranged in a loop configuration producing 30W of ASE output with near-diffraction-limited spatial quality, with M(2)vertical, at an ~38% optical-to-optical conversion efficiency.

  16. Power scaling of a picosecond vortex laser based on a stressed Yb-doped fiber amplifier.

    Science.gov (United States)

    Koyama, Mio; Hirose, Tetsuya; Okida, Masahito; Miyamoto, Katsuhiko; Omatsu, Takashige

    2011-01-17

    Power scaling of a picosecond vortex laser based on a stressed Yb-doped fiber amplifier is analyzed. An output power of 25 W was obtained for 53 W of pumping, with a peak power of 37 kW. Frequency doubling of the vortex output was demonstrated using a nonlinear PPSLT crystal. A second-harmonic output power of up to 1.5 W was measured at a fundamental power of 11.2 W.

  17. Coherent Combining of High-Power Yb Fiber Amplifiers

    Science.gov (United States)

    2011-04-20

    the power~in-the-bucket ( PIB ) vertical beam quality (VBQ) [J 5], which is a related to the fraction of the power within a given far-field angle...compared with a reference ideal beam (the ideal tophat in this case). The power-in- the-bucket ( PIB ) vertical beam quality (VBQ) [I 5] is given by (c/ay!ll

  18. Multi-Watt femtosecond optical parametric master oscillator power amplifier at 43 MHz.

    Science.gov (United States)

    Mörz, Florian; Steinle, Tobias; Steinmann, Andy; Giessen, Harald

    2015-09-07

    We present a high repetition rate mid-infrared optical parametric master oscillator power amplifier (MOPA) scheme, which is tunable from 1370 to 4120nm. Up to 4.3W average output power are generated at 1370nm, corresponding to a photon conversion efficiency of 78%. Bandwidths of 6 to 12nm with pulse durations between 250 and 400fs have been measured. Strong conversion saturation over the whole signal range is observed, resulting in excellent power stability. The system consists of a fiber-feedback optical parametric oscillator that seeds an optical parametric power amplifier. Both systems are pumped by the same Yb:KGW femtosecond oscillator.

  19. The Use of a Solid State Analog Television Transmitter as a Superconducting Electron Gun Power Amplifier

    Energy Technology Data Exchange (ETDEWEB)

    J.G. Kulpin, K.J. Kleman, R.A. Legg

    2012-07-01

    A solid state analog television transmitter designed for 200 MHz operation is being commissioned as a radio frequency power amplifier on the Wisconsin superconducting electron gun cavity. The amplifier consists of three separate radio frequency power combiner cabinets and one monitor and control cabinet. The transmitter employs rugged field effect transistors built into one kilowatt drawers that are individually hot swappable at maximum continuous power output. The total combined power of the transmitter system is 33 kW at 200 MHz, output through a standard coaxial transmission line. A low level radio frequency system is employed to digitally synthesize the 200 MHz signal and precisely control amplitude and phase.

  20. A Ku-band high power density AlGaN/GaN HEMT monolithic power amplifier

    Institute of Scientific and Technical Information of China (English)

    Ge Qin; Chen Xiaojuan; Luo Weijun; Yuan Tingting; Pang Lei; Liu Xinyu

    2011-01-01

    A high power density monolithic power amplifier operated at Ku band is presented utilizing a 0.3 μm AlGaN/GaN HEMT production process on a 2-inch diameter semi-insulating (SI) 4H-SiC substrate by MOCVD.Over the 12-14 GHz frequency range,the single chip amplifier demonstrates a maximum power of 38 dBm (6.3 W),a peak power added efficiency (PAE) of 24.2% and linear gain of 6.4 to 7.5 dB under a 10% duty pulse conditionwhen operated at Vds =25 V and Vgs =-4 V.At these power levels,the amplifier exhibits a power density in excess of 5 W/mm.

  1. Adaptive Digital Predistortion with Iterative Noise Cancelation for Power Amplifier Linearization

    Science.gov (United States)

    Jeon, Sungho; Kim, Junghyun; Lee, Jaekwon; Suh, Young-Woo; Seo, Jong-Soo

    In this paper, we propose a power amplifier linearization technique combined with iterative noise cancelation. This method alleviates the effect of added noises which prevents the predistorter (PD) from estimating the exact characteristics of the power amplifier (PA). To iteratively cancel the noise added in the feedback signal, the output signal of the power amplifier without noise is reconstructed by applying the inverse characteristics of the PD to the predistorted signals. The noise can be revealed by subtracting the reconstructed signals from the feedback signals. Simulation results based on the mean-square error (MSE) and power spectral density (PSD) criteria are presented to evaluate PD performance. The results show that the iterative noise cancelation significantly enhances the MSE performance, which leads to an improvement of the out-of-band power suppression. The performance of the proposed technique is verified by computer simulation and hardware test results.

  2. High efficiency WCDMA power amplifier with Pulsed Load Modulation (PLM) technique

    Science.gov (United States)

    Liao, Shu-Hsien

    In wireless communication, high data rate complex modulation is used for spectral efficiency. However, power efficiency of power amplifier degrades when complex modulation is applied. Therefore, efficiency enhancement is necessary to maintain the performance. However, conventional efficiency enhancement schemes are nonlinear and performance improvement can only be optimized over a small range of power level. In order to preserve linearity and power efficiency, we propose a new digital power amplification technique "Pulsed Load Modulation (PLM)" for high efficiency and linear amplification. The PLM technique realizes load impedance modulation in digital fashion which is insensitive to device nonlinearity. Furthermore, the optimum power efficiency can be maintained over a wide range of output power. In this work, a PLM power amplifier module has been fabricated and to demonstrate the ability of PLM to provide high efficiency and linear amplification.

  3. An Octave Bandwidth, High PAE, Linear, Class J GaN High Power Amplifier

    Science.gov (United States)

    2012-03-12

    versus the modeled small-signal gain and return loss response of the Class J amplifier using a 45-W CREE GaN HEMT . The amplifier has a gain of 13 to...AFFTC-PA-12055 An Octave Bandwidth, High PAE, Linear, Class J GaN High Power Amplifier Kris Skowronski, Steve Nelson, Rajesh Mongia, Howard...Technical Paper 3. DATES COVERED (From - To) 11/11 – 03/12 (etc.) 4. TITLE AND SUBTITLE An Octave Bandwidth, High PAE, Linear, Class J GaN High

  4. 2.45 GHz Class E Power Amplifier for a Transmitter Combining LINC and EER

    Directory of Open Access Journals (Sweden)

    M. Dirix

    2009-01-01

    Full Text Available A 10 W class-E RF power amplifier (PA is designed and fabricated using a Cree GaN HEMT. The proposed PA uses an innovative input circuit to optimize band with. At 2.45 GHz the PA achieves a PAE of 60 % at an outputpower of 40 dBm. The resulting amplifier is simulated and constructed using a transmissionline topology. Two of these amplifiers are fabricated on a single board for outphasing application. Their suitability for outphasing application and supply modulation is investigated. 

  5. New Driver For The Powerful Output Rf Amplifier Of Mmf Dtl Rf System

    CERN Document Server

    Kvasha, A I; Vassilyev, A G

    2004-01-01

    More than 30 years ago a few powerful vacuum tubes were specially designed and produced in the former design office Swetlana for the Moscow meson factory DTL RF system. Among them was tetrode GI-51A with output pulse RF power up to 300 kW at frequency 198.2 MHz, which was used as driver for RF power amplifier with output RF pulse power (2-3) MW. In connection with well-known events in our country manufacture of these tubes, including GI-51A was finished about 10 years ago. In "SED-SPb" (successor of the design office Swetlana) triode GI-57A was offered instead of GI-51A. In this paper results of calculations and design of RF amplifier with new triode are presented. Preliminary results of RF amplifier tests, also presented in the paper, showed that triode GI-57A will be able successfully used in the DTL RF system channels.

  6. Generation of high energy and good beam quality pulses with a master oscillator power amplifier

    Institute of Scientific and Technical Information of China (English)

    Zhigang Li(李志刚); Z.Xiong; Nicholas Moore; Chen Tao; G.C.Lim; Weiling Huang(黄维玲); Dexiu Huang(黄德修)

    2004-01-01

    A high efficiency and high peak power laser system with short-pulse and good beam quality has been demonstrated by using a master oscillator power amplifier with two-pass amplification configuration. The master oscillator, end-pumped with a fiber-coupled laser diode array, provides low power but excellent beam quality pulses, and the amplifier boosts the pulse energy by orders without significant beam quality degradation. Short pulses of 8.5 ns with energy up to 130 mJ and approximately diffraction limited beam quality have been demonstrated.

  7. Efficient operation of a high-power {ital X}-band traveling wave tube amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.; Xu, Z.; Ivers, J.D.; Nation, J.A.; Naqvi, S.; Schachter, L. [Cornell University, Ithaca, New York 14853 (United States)

    1999-10-01

    We report experimental results demonstrating 54{percent} power conversion efficiency (43{percent} energy conversion efficiency), from a two-stage {ital X}-band traveling wave tube amplifier designed for high-power operation. The first stage of the amplifier is a 12-cm-long Boron Nitride dielectric section used to modulate the electron beam. The second stage consists of a long high-phase-velocity bunching section followed by a short low-phase-velocity output section. Output powers of up to 78 MW with narrow spectrum width were obtained with {approximately}700 kV, {approximately}200 A beam. {copyright} {ital 1999 American Institute of Physics.}

  8. Single frequency 1083nm ytterbium doped fiber master oscillator power amplifier laser.

    Science.gov (United States)

    Huang, Shenghong; Qin, Guanshi; Shirakawa, Akira; Musha, Mitsuru; Ueda, Ken-Ichi

    2005-09-05

    Single frequency 1083nm ytterbium fiber master oscillator power amplifier system was demonstrated. The oscillator was a linear fiber cavity with loop mirror filter and polarization controller. The loop mirror with unpumped ytterbium fiber as a narrow bandwidth filter discriminated and selected laser longitudinal modes efficiently. Spatial hole burning effect was restrained by adjusting polarization controller appropriately in the linear cavity. The amplifier was 5 m ytterbium doped fiber pumped by 976nm pigtail coupled laser diode. The linewidth of the single frequency laser was about 2 KHz. Output power up to 177 mW was produced under the launched pump power of 332 mW.

  9. The Paralleling of High Power High Frequency Amplifier Based on Synchronous and Asynchronous Control

    Institute of Scientific and Technical Information of China (English)

    程荣仓; 刘正之

    2004-01-01

    The vertical position of plasma in the HT-7U Tokamak is inherently unstable. In order to realize active stabilization, the response rate of the high-power high-frequency amplifier feeding the active control coils must be fast enough. This paper analyzes the paralleling scheme of the power amplifier through two kinds of control mode. One is the synchronous control; the other is the asynchronous control. Via the comparison of the two kinds of control mode, both of their characteristics are given in the text. At last, the analyzed result is verified by a small power experiment.

  10. A novel technique for electronic phasing of high power fiber amplifier arrays

    Science.gov (United States)

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

    2009-06-01

    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.

  11. Piecewise-polynomial and cascade models of predistorter for linearization of power amplifier

    OpenAIRE

    2012-01-01

    To combat non-linear signal distortions in a power amplifier we suggest using predistorter with cascade structure in which first and second nodes have piecewise-polynomial and polynomial models. On example of linearizing the Winner–Hammerstein amplifier model we demonstrate that cascade structure of predistorter improves precision of amplifier’s linearization. To simplify predistorter’s synthesis the degree of polynomial model used in first node should be moderate, while precision should be i...

  12. Generation of sub-50 fs pulses from a high-power Yb-doped fiber amplifier.

    Science.gov (United States)

    Deng, Yujun; Chien, Ching-Yuan; Fidric, Bernard G; Kafka, James D

    2009-11-15

    We demonstrate the generation of 48 fs pulses with 18 W average power and 226 nJ of pulse energy from a Yb-doped fiber amplifier. The system uses a simple stretcher-free single-stage amplifier configuration operating in the parabolic pulse regime. The gain fiber length and pump wavelength are chosen in order to reduce the gain per unit length and generate both shorter pulses and higher pulse energy.

  13. High power picosecond vortex laser based on a large-mode-area fiber amplifier.

    Science.gov (United States)

    Tanaka, Yuichi; Okida, Masahito; Miyamoto, Katsuhiko; Omatsu, Takashige

    2009-08-03

    We present the production of picosecond vortex pulses from a stressed large-mode-area fiber amplifier for the first time. 8.5 W picosecond output with a peak power of approximately 12.5 kW was obtained at a pump power of 29 W. 2009 Optical Society of America.

  14. Efficiency Enhancement of an Envelope Tracking Power Amplifier Combining Supply Shaping and Dynamic Biasing

    DEFF Research Database (Denmark)

    Tafuri, Felice Francesco; Sira, Daniel; Jensen, Ole Kiel

    2013-01-01

    of the input envelope by means of two shaping functions jointly designed on the basis of a single-tone characterization. The presented technique is demonstrated by means of measurements on a commercial GaAs HBT power amplifier. Measured results showed a PA power added efficiency (PAE) of 51.9%, an error vector...

  15. Millimeter‐wave INP DHBT power amplifier based on power‐optimized cascode configuration

    DEFF Research Database (Denmark)

    Johansen, Tom K.; Yan, Lei; Dupuy, Jean‐Yves;

    2013-01-01

    This letter describes the use of a power‐optimized cascode configuration for obtaining maximum output power at millimeter‐wave (mm‐wave) frequencies for a two‐way combined power amplifier (PA). The PA has been fabricated in a high‐speed InP double heterojunction bipolar transistor technology...

  16. Design Methodology of High Power Distributed Amplifier Employing Broadband Impedance Transformer

    DEFF Research Database (Denmark)

    Narendra, Kumar; Zhurbenko, Vitaliy; Collantes, Juan Mari;

    2009-01-01

    A novel topology of a high power distributed amplifier (DA) in combination with a broadband impedance transformer is presented. The advantages of the proposed topology are explored analytically and verified by a full-wave 3D simulations. Stability of the high power DA is verified with the pole...

  17. High Power Uplink Amplifier for Deep Space Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Critical to the success of delivering on the promise of deep space optical communications is the creation of a stable and reliable high power multichannel optical...

  18. Finite-duration Seeding Effects in Powerful Backward Raman Amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    N.A. Yampolsky; V.M. Malkin; N.J. Fisch

    2003-07-14

    In the process of backward Raman amplification (BRA), the leading layers of the seed laser pulse can shadow the rear layers, thus weakening the effective seeding power and affecting parameters of output pulses in BRA. We study this effect numerically and also analytically by approximating the pumped pulse by the ''*-pulse'' manifold of self-similar solutions. We determine how the pumped pulse projection moves within the *-pulse manifold, and describe quantitatively the effective seeding power evolution. Our results extend the quantitative theory of BRA to regimes where the effective seeding power varies substantially during the amplification. These results might be of broader interest, since the basic equations, are general equations for resonant 3-wave interactions.

  19. Design of a new VHF RF power amplifier system for LANSCE

    Energy Technology Data Exchange (ETDEWEB)

    Lyles, John T M [Los Alamos National Laboratory

    2010-01-01

    A major upgrade is replacing much of the 40 year-old proton drift tube linac RF system with new components at the Los Alamos Neutron Science Center (LANSCE). When installed, the new system will reduce the total number of electron power tubes from twenty-four to eight in the RF powerplant. A new 200 MHz high power cavity amplifier has being developed at LANSCE. This 3.2 MW final power amplifier (FPA) uses a Thales TH628 Diacrode{reg_sign}, a state-of-the-art tetrode that eliminates the large anode modulator of the triode-based FPA that has been in use for four decades. Drive power for the FPA is provided by a new tetrode intermediate power amplifier (and a solid-state driver stage). The new system has sufficient duty-factor capability to allow LANSCE to return to 1 MW beam operation. Prototype RF power amplifiers have been designed, fabricated, and assembled, and are being tested. High voltage DC power became available through innovative re-engineering of an installed system. Details of the electrical and mechanical design of the FPA and ancillary systems are discussed.

  20. Monolithic Microwave Integrated Circuits (MMIC) Broadband Power Amplifiers

    Science.gov (United States)

    2012-12-01

    Pcomp-6x50 µm PHEMT). .............4 Figure 4. An 8-GHz load-pull simulation of PAE (6x50 µm PHEMT). ........................................4...layout. ..........................................................................9 Figure 12. MMIC 5–11 GHz output power and PAE performance...6x50 µm PHEMT). ...........11 Figure 16. A 4-GHz load-pull simulation of PAE (6x50 µm PHEMT). ......................................12 Figure 17

  1. The power stability of a fiber amplifier based on a multifunction card and PID control program

    Science.gov (United States)

    Zhang, Linjie; Yang, Wenguang; Zhang, Hao; Zhao, JianMing; Jia, Suotang

    2016-06-01

    The power stability of a fiber amplifier was significantly improved by means of simultaneously controlling the current of a fiber amplifier and the diffraction efficiency of an acousto-optical modulator. The real-time fluctuation of laser power was recorded by a multifunction card and processed by a proportional-integral-derivative (PID) control program. The feedback loop voltage was introduced to the fiber laser amplifier and acoustic-optic modulator through the analog output of the multifunction card. The control method based on a multifunction card and PID program has good scalability, flexibility and reliability for the complex system on the condition in which the frequency and power of the laser need to be precisely stabilized.

  2. Concentric Parallel Combining Balun for Millimeter-Wave Power Amplifier in Low-Power CMOS with High-Power Density

    Science.gov (United States)

    Han, Jiang-An; Kong, Zhi-Hui; Ma, Kaixue; Yeo, Kiat Seng; Lim, Wei Meng

    2016-11-01

    This paper presents a novel balun for a millimeter-wave power amplifier (PA) design to achieve high-power density in a 65-nm low-power (LP) CMOS process. By using a concentric winding technique, the proposed parallel combining balun with compact size accomplishes power combining and unbalance-balance conversion concurrently. For calculating its power combination efficiency in the condition of various amplitude and phase wave components, a method basing on S-parameters is derived. Based on the proposed parallel combining balun, a fabricated 60-GHz industrial, scientific, and medical (ISM) band PA with single-ended I/O achieves an 18.9-dB gain and an 8.8-dBm output power at 1-dB compression and 14.3-dBm saturated output power ( P sat) at 62 GHz. This PA occupying only a 0.10-mm2 core area has demonstrated a high-power density of 269.15 mW/mm2 in 65 nm LP CMOS.

  3. Benefits of active transmit balanced antenna fed by differential power amplifier

    OpenAIRE

    Sagor, Md. Hasanuzzaman; Callaghan, Peter

    2014-01-01

    A differential amplifier feeding a balanced antenna is investigated experimentally. This approach would suit modern RFIC design rather than using a 50Ω unbalanced connection. As such the balun or power-combining network is eliminated resulting in a compact RF front-end design with wider bandwidth and lower losses. Experimental result shows that this technique promises higher output power compared to conventional feeding approach while using same RFIC and same power supply.

  4. Low-cost high-efficient 10-Watt X-band high-power amplifier

    NARCIS (Netherlands)

    Bent, G. van der; Hek, A.P. de; Bessemoulin, A.; Vliet, F.E. van

    2009-01-01

    A high power X-band amplifier with an output power over 10 Watts and a Power Added Efficiency (PAE) in excess of 40 percent has been developed. The design was fabricated in a 0.25 μm pHEMT GaAs process (WIN Semiconductor PP25-01). The small die area in combination with a 6-inch wafer technology prov

  5. Hard Horn Design for Quasi-Optical Power Combining Using Solid-State Power Amplifiers

    Science.gov (United States)

    Pickens, W. S.; Epp, L. W.; Hoppe, D. J.

    2004-02-01

    In recent years, there has been significant interest in the use of corrugated, periodic structures to control the wave impedance of a given surface. It has been shown [1] that a quasi-transverse-electromagnetic (TEM) wave can be excited in a waveguide by correctly choosing the impedance at the guide wall. This correctly chosen impedance is referred to as the hard boundary condition. We have taken advantage of this property of the so-called "hard" guide to attempt to create a spatial power combiner/splitter that couples to an array of microstrip patch antennas feeding a bank of monolithic microwave integrated circuit (MMIC) power amplifiers. The hard horn described here employs longitudinal corrugations filled with a low-loss dielectric material along the vertical walls to achieve the hard boundary condition. We believe the use of dielectric-filled corrugations will improve the insertion loss performance over that of a hard guide using dielectric slabs bonded to the guide wall. Additionally, the horn is tapered to its maximum aperture along a cosine curve in order to improve return loss performance. Included in this article is a discussion of the fabrication process of prototype hard horns, measurements of a hard horn prototype, and preliminary modal analysis results.

  6. High-gain Yb:YAG amplifier for ultrashort pulse laser at high-average power

    Science.gov (United States)

    Vetrovec, John; Copeland, Drew A.; Litt, Amardeep S.; Du, Detao

    2016-03-01

    We report on a Yb:YAG laser amplifier for ultrashort pulse applications at kW-class average power. The laser uses two large-aperture, disk-type gain elements fabricated from composite ceramic YAG material, and a multi-pass extraction architecture to obtain high gain in a chirped-pulse amplification system. The disks are edge-pumped, thus allowing for reduced doping of host material with laser ions, which translates to lower lasing threshold and lower heat dissipation in the Yb:YAG material. The latter makes it possible to amplify a near diffraction-limited seed without significant thermo-optical distortions. This work presents results of testing the laser amplifier with relay optics configured for energy extraction with up to 40 passes through the disks. Applications for the ultrashort pulse laser amplifier include producing laser-induced plasma channel, laser material ablation, and laser acceleration of atomic particles.

  7. High-power, 1-ps, all-Yb:YAG thin-disk regenerative amplifier.

    Science.gov (United States)

    Fattahi, Hanieh; Alismail, Ayman; Wang, Haochuan; Brons, Jonathan; Pronin, Oleg; Buberl, Theresa; Vámos, Lénárd; Arisholm, Gunnar; Azzeer, Abdallah M; Krausz, Ferenc

    2016-03-15

    We report a 100 W, 20 mJ, 1-ps, all-Yb:YAG thin-disk regenerative amplifier seeded by a microjoule-level Yb:YAG thin-disk Kerr-lens mode-locked oscillator. The regenerative amplifier is implemented in a chirped pulse amplification system and operates at an ambient temperature in air, delivering ultrastable output pulses at a 5 kHz repetition rate and with a root mean square power noise value of less than 0.5%. Second harmonic generation of the amplifier's output in a 1.5 mm-thick BBO crystal results in more than 70 W at 515 nm, making the system an attractive source for pumping optical parametric chirped pulse amplifiers in the visible and near-infrared spectral ranges.

  8. Digital audio broadcasting: Measuring techniques and coverage performance for a medium power VHF single frequency network

    Science.gov (United States)

    Maddocks, M. C. D.; Eng, C.; Pullen, I. R.; Green, J. A.

    1995-02-01

    The advent of digital formats such as CD has created demand for uniformly high audio quality from radio. In order to provide such high-quality stereo reception, a Digital Audio Broadcasting (DAB) system capable of reliable reception in vehicles and on portables has been developed by the European EUREKA 147 Project. As a VHF frequency allocation would appear most suitable for the introduction of terrestrial broadcasting of DAB in the United Kingdom, the BBC is undertaking a major experiment to test the EUREKA DAB system and to generate data to allow efficient planning of its transmitter network. A network of four, 1 kW e.r.p., VHF transmitters has been installed to cover the London area in England. This Report describes the experimental program and the rationale and measurement techniques behind it. The results show a wide-area coverage from the transmitter network which is in reasonable agreement with computer predictions. This indicates that the current transmitting and receiving equipment (built to the EUREKA specification) is operating in the way that would be expected from theoretical studies and simulation. The results also provide quantitative values which can be used for coverage prediction and for international co-ordination of services. Finally, the performance of the system demonstrates a number of the benefits of the EUREKA DAB system for mobile and portable reception.

  9. Linearization and efficiency enhancement techniques for silicon power amplifiers from RF to mmW

    CERN Document Server

    Kerhervé, Eric

    2015-01-01

    This book provides an overview of current efficiency enhancement and linearization techniques for silicon power amplifier designs. It examines the latest state of the art technologies and design techniques to address challenges for RF cellular mobile, base stations, and RF and mmW WLAN applications. Coverage includes material on current silicon (CMOS, SiGe) RF and mmW power amplifier designs, focusing on advantages and disadvantages compared with traditional GaAs implementations. With this book you will learn: The principles of linearization and efficiency improvement techniquesThe arch

  10. Design of Digital Predistortion Technique for RF Power Amplifier using Memory Polynomial

    Directory of Open Access Journals (Sweden)

    Er. Sweety Badhwar

    2014-09-01

    Full Text Available Linearization of power amplifier has been an area of intense research from the last many years. The various types of linearization techniques are available for linearising PA but Digital Predistortion technique has been observed as one of the most common and effective method. But due to the issues like memory effects and exact characterization of non-linear behaviour of power amplifier, the implementation of existing predistortion technique suffers. So in this paper, a digital predistorter based on memory polynomial has been proposed that takes care of above mentioned issues. The presented technique is easy to implement and simple.

  11. High-Power Er3+/Yb3+ Codoped Double-Cladding Fibre Amplifier with More Than 2 W Output Power

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-Ge; FENG Xin-Huan; LI Li-Jun; LI Yao; YUAN Shu-Zhong; KAI Gui-Yun; LI Yi-Gang; DONG Xiao-Yi

    2005-01-01

    @@ A high-power Er3+/Yb3+-codoped double-cladding all-fibre amplifier was successfully demonstrated and experimentally investigated. The amplifier could be operated with a maximum output power of 2.18 W and 2.11 W at 1541nm and 1550nm wavelengths, respectively, when the maximum pump power was 6.07W. The power conversion efficiency was up to 35.6% and 34.4% at the two wavelengths, respectively. The output power and the gain were greater than 2.00 W and 20.0dB, respectively, in the wavelength range from 1539nm to 1565nm for 20.0mW input signal power. The gain fluctuation and the noise figure around 1550nm wavelength were less than 0.3 dB and 6.0 dB, respectively.

  12. Studies on Nd∶YAG Single-pass Amplifiers for High-power Q-switched Laser System

    Institute of Scientific and Technical Information of China (English)

    CAO Sansong(曹三松); ZHANG Xiangyang(张向阳); HUANG Yanlin(黄燕琳); LI Guangrong(李光荣); SU Xinzhi(苏心智)

    2002-01-01

    The output of Nd∶YAG single-pass laser amplifiers is studied analytically and experimentally. Methods of analysis for single-pass Nd∶YAG laser amplifier are presented. A flashlamp-pumped Q-switched Nd∶YAG oscillator/amplifier laser system has been developed with the average output power of 121.5 W.

  13. Analytical Design Equations for Class-E Power Amplifiers with Finite DC-Feed Inductance and Switch On-Resistance

    NARCIS (Netherlands)

    Acar, Mustafa; Annema, Anne Johan; Nauta, Bram

    2007-01-01

    Many critical design trade-offs of the class-E power amplifier (e.g power efficiency) are influenced by the switch on-resistance and the value of dc-feed drain inductance. In literature, the time-domain mathematical analyses of the class-E power amplifier with finite dc-feed inductance assume zero s

  14. Audio Twister

    DEFF Research Database (Denmark)

    Cermak, Daniel; Moreno Garcia, Rodrigo; Monastiridis, Stefanos

    2015-01-01

    Daniel Cermak-Sassenrath, Rodrigo Moreno Garcia, Stefanos Monastiridis. Audio Twister. Installation. P-Hack Copenhagen 2015, Copenhagen, DK, Apr 24, 2015.......Daniel Cermak-Sassenrath, Rodrigo Moreno Garcia, Stefanos Monastiridis. Audio Twister. Installation. P-Hack Copenhagen 2015, Copenhagen, DK, Apr 24, 2015....

  15. A digitally controlled power amplifier with neutralization capacitors for Zigbee™ applications

    Science.gov (United States)

    Fei, Jia; Shengxi, Diao; Xuejuan, Zhang; Zhongqian, Fu; Fujiang, Lin

    2012-12-01

    This paper presents a single chip CMOS power amplifier with neutralization capacitors for Zigbee™ system according to IEEE 802.15.4. A novel structure with digital interface is adopted, which allows the output power of a PA to be controlled by baseband signal directly, so there is no need for DAC. The neutralization capacitors will increase reverse isolation. The chip is implemented in SMIC 0.18 μm CMOS technology. Measurement shows that the proposed power amplifier has a 13.5 dB power gain, 3.48 dBm output power and 35.1% PAE at P1dB point. The core area is 0.73 × 0.55 mm2.

  16. Broadband Fiber Raman Power-Amplifier for Narrow Linewidth Tunable Seed Lasers Used in Spectroscopic Sensing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an energy and space efficient high power continuous wave (cw) narrow linewidth broadband fiber Raman amplifier (FRA) with spectrally tunable...

  17. A High-Voltage class-D power amplifier with switching frequency regulation for improved high-efficiency output power range

    NARCIS (Netherlands)

    Ma, Haifeng; Zee, van der Ronan; Nauta, Bram

    2015-01-01

    This paper describes the power dissipation analysis and the design of an efficiency-improved high-voltage class-D power amplifier. The amplifier adaptively regulates its switching frequency for optimal power efficiency across the full output power range. This is based on detecting the switching outp

  18. Compressed sensing based joint-compensation of power amplifier's distortions in OFDMA cognitive radio systems

    KAUST Repository

    Ali, Anum Z.

    2013-12-01

    Linearization of user equipment power amplifiers driven by orthogonal frequency division multiplexing signals is addressed in this paper. Particular attention is paid to the power efficient operation of an orthogonal frequency division multiple access cognitive radio system and realization of such a system using compressed sensing. Specifically, precompensated overdriven amplifiers are employed at the mobile terminal. Over-driven amplifiers result in in-band distortions and out of band interference. Out of band interference mostly occupies the spectrum of inactive users, whereas the in-band distortions are mitigated using compressed sensing at the receiver. It is also shown that the performance of the proposed scheme can be further enhanced using multiple measurements of the distortion signal in single-input multi-output systems. Numerical results verify the ability of the proposed setup to improve error vector magnitude, bit error rate, outage capacity and mean squared error. © 2011 IEEE.

  19. Third-order Intermodulation Reduction in Mobile Power Amplifiers by the First Stage Bias Control

    Directory of Open Access Journals (Sweden)

    J. H. Jung

    2012-06-01

    Full Text Available In this paper, the third order intermodulation distortion (IMD3 of three-stage power amplifier (PA is analyzed using the Volterra series. The analysis explains how the total IMD3 of the three-stage power amplifier can be reduced by the first-stage bias condition. The three-stage PA, which is fabricated using InGaP/GaAs hetero-junction bipolar transistor (HBT, operates with an optimized first driver stage bias for higher P1dB and good gain flatness. The power amplifier has been designed for 1626.5 MHz~1660.5 MHz satellite mobile communications. With π/4 DQPSK modulation signals, this PA can deliver a highly linear output power of 33 dBm from 3.6V supply voltage. At 33 dBm output power, it shows a gain of 31.9 dB, a power-added efficiency (PAE of 39.8%, an adjacent channel power ratio (ACPR of -28.2 dBc at a 31.25 KHz offset frequency.

  20. Stability investigation for InP DHBT mm‐wave power amplifier

    DEFF Research Database (Denmark)

    Yan, Lei; Johansen, Tom Keinicke; Kammersgaard, Jacob

    2013-01-01

    In this article, we discuss stability issues for mm‐wave monolithic integrated power amplifiers using InP double heterojunction bipolar transistor (DHBT) technology targeting E‐band applications at 71–76 GHz and 81–86 GHz. Different stability detection methods based on the classical two‐port K...

  1. Efficiency Investigation of Switch Mode Power Amplifier Drving Low Impedance Transducers

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Schneider, Henrik; Knott, Arnold;

    2015-01-01

    the amplifier rail voltage requirement as a function of the voice coil nominal resistance is presented. The method is based on a crest factor analysis of music signals and estimation of the electrical power requirement from a specific target of the sound pressure level. Experimental measurements confirms a huge...

  2. 47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

    Science.gov (United States)

    2010-10-01

    ... person shall use, manufacture, sell or lease, offer for sale or lease (including advertising for sale or lease), or import, ship, or distribute for the purpose of selling or leasing, any external radio... separate product. (1) An external radio frequency power amplifier may be marketed for individual...

  3. Generalized Design Equations for Class-E Power Amplifiers with Finite DC Feed Inductance

    NARCIS (Netherlands)

    Acar, M.; Annema, A.J.; Nauta, B.

    2006-01-01

    In literature, it is widely accepted that the design of Class-E Power Amplifier (PA) with finite dc feed inductance requires a long iterative solution procedure. To avoid such iterative solution methods, analytical design equations should be known. The problem associated with the finite dc feed indu

  4. Design and modeling of InP DHBT power amplifiers at millimeter-wave frequencies

    DEFF Research Database (Denmark)

    Yan, Lei; Johansen, Tom K.

    2012-01-01

    In this paper, the design and modeling of InP DHBT based millimeter-wave(mm-wave) power amplifiers is described. This includes the modeling of InP DHBT devices and layout parasitics. An EM-circuit co-simulation approach is described to allow all parasitics to be modeled for accurate circuit...

  5. Thermo-optical effects in high-power Ytterbium-doped fiber amplifiers

    DEFF Research Database (Denmark)

    Hansen, Kristian Rymann; Alkeskjold, Thomas Tanggaard; Broeng, Jes

    2011-01-01

    We investigate the effect of temperature gradients in high-power Yb-doped fiber amplifiers by a numerical beam propagation model, which takes thermal effects into account in a self-consistent way. The thermally induced change in the refractive index of the fiber leads to a thermal lensing effect,...

  6. Extended Cann Model for Behavioral Modeling of Envelope Tracking Power Amplifiers

    DEFF Research Database (Denmark)

    Tafuri, Felice Francesco; Larsen, Torben

    2013-01-01

    This paper deals with behavioral modeling of power amplifiers (PAs) for envelope tracking (ET) applications. In such a scenario, the power supply modulation brings in several additional challenges for the system design and, similarly, it becomes more difficult to obtain an accurate and general PA...... by the ET operation. The model performance is tested modeling data-sets acquired from an ET test bench including a commercial RFMD PA and an envelope modulator designed using a commercial IC from TI....

  7. Dynamic Floating Output Stage for Low Power Buffer Amplifier for LCD Application

    Directory of Open Access Journals (Sweden)

    Hari Shanker Srivastava

    2015-02-01

    Full Text Available This topic proposes low-power buffer means low quiescent current buffer amplifier. A dynamic floating current node is used at the output of two-stage amplifier to increase the charging and discharging of output capacitor as well as settling time of buffer. It is designed for 10 bit digital analog converter to support for LCD column driver it is implemented in 180 nm CMOS technology with the quiescent current of 5 µA for 30 pF capacitance, the settling time calculated as 4.5µs, the slew rate obtained as 5V/µs and area on chip is 30×72µ

  8. High-power linearly-polarized picosecond thulium-doped all-fiber master-oscillator power-amplifier.

    Science.gov (United States)

    Liu, Jiang; Liu, Chen; Shi, Hongxing; Wang, Pu

    2016-06-27

    We demonstrated a linearly-polarized picosecond thulium-doped all-fiber-integrated master-oscillator power-amplifier system, which yielded 240 W of average output power at 127 MHz repetition rate. The seed source is a passively mode-locked polarization-maintaining thulium-doped all-fiber oscillator with a nearly transform-limited pulse duration of 10 ps. In combination with a pre-chirp fiber having a positive group velocity dispersion and a three stage polarization-maintaining thulium-doped all-fiber amplifier, output pulse energies up to 1.89 µJ with 42 kW pulse peak power are obtained without the need of complex free-space stretcher or compressor setups. To the best of our knowledge, this is the highest average output power ever reported for a picosecond all-fiber-integrated laser at 2 µm wavelength region.

  9. Automatic Frequency Controller for Power Amplifiers Used in Bio-Implanted Applications: Issues and Challenges

    Directory of Open Access Journals (Sweden)

    Mahammad A. Hannan

    2014-12-01

    Full Text Available With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil’s mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning

  10. Automatic frequency controller for power amplifiers used in bio-implanted applications: issues and challenges.

    Science.gov (United States)

    Hannan, Mahammad A; Hussein, Hussein A; Mutashar, Saad; Samad, Salina A; Hussain, Aini

    2014-12-11

    With the development of communication technologies, the use of wireless systems in biomedical implanted devices has become very useful. Bio-implantable devices are electronic devices which are used for treatment and monitoring brain implants, pacemakers, cochlear implants, retinal implants and so on. The inductive coupling link is used to transmit power and data between the primary and secondary sides of the biomedical implanted system, in which efficient power amplifier is very much needed to ensure the best data transmission rates and low power losses. However, the efficiency of the implanted devices depends on the circuit design, controller, load variation, changes of radio frequency coil's mutual displacement and coupling coefficients. This paper provides a comprehensive survey on various power amplifier classes and their characteristics, efficiency and controller techniques that have been used in bio-implants. The automatic frequency controller used in biomedical implants such as gate drive switching control, closed loop power control, voltage controlled oscillator, capacitor control and microcontroller frequency control have been explained. Most of these techniques keep the resonance frequency stable in transcutaneous power transfer between the external coil and the coil implanted inside the body. Detailed information including carrier frequency, power efficiency, coils displacement, power consumption, supplied voltage and CMOS chip for the controllers techniques are investigated and summarized in the provided tables. From the rigorous review, it is observed that the existing automatic frequency controller technologies are more or less can capable of performing well in the implant devices; however, the systems are still not up to the mark. Accordingly, current challenges and problems of the typical automatic frequency controller techniques for power amplifiers are illustrated, with a brief suggestions and discussion section concerning the progress of

  11. Tri-state Modulation Power Driving of Electro-hydraulic Proportional Amplifier

    Institute of Scientific and Technical Information of China (English)

    NIE Yong; WANG Qingfeng

    2009-01-01

    Switch electro-hydraulic proportional amplifier(PA) widely employs single switch modulation power driving(SSMPD) or reverse discharging power driving(RDPD) at present. SSMPD has slow dynamic response, and can't adjust independently the dither signal's amplitude and frequency;RDPD accelerates the current decay;consequently, it increases current ripple and power loss. For the purpose of solving the above mentioned problem, the tri-state modulation power driving(TSMPD) scheme was proposed for improving the performance of power driving. Detailedly, the hardware circuit for the tri-state modulation power driving is designed;the tri-state modulation algorithm is realized by digital signal processor(DSP). The tri-state modulation power driving is investigated by experiments, comparetive experiments among the single switch modulation power driving(SSMPD), reverse discharging power driving(RDPD), and the TSMPD are implemented, and the experimental results demonstrate that the linearity error of TSMDP meets the requirement of PA;the current response of TSMSP is the best;the amplitude of ripple current of the TSMPD can be reduced without increasing frequency of PWM, in addition, dither signal amplitude and frequency can be adjusted independently for each other. It is very meaningful to guide the development of high performance proportional amplifier for high frequency response proportional solenoid.

  12. F-band, High-Efficiency GaN Power Amplifier for the Scanning Microwave Limb Sounder and SOFIA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — QuinStar Technology proposes to develop a 4-watt Solid-State Power Amplifier (SSPA) operating at F-band (106-114 GHz) with a power-added efficiency (PAE) of greater...

  13. 0.18μm CMOS Low Voltage Power Amplifier For WSN Application

    Directory of Open Access Journals (Sweden)

    Wu Chenjian

    2013-08-01

    Full Text Available This paper presents the design of a Class A/B power amplifier (PA for 2.4-2.4835GHz Wireless Sensor Network (WSN system in 0.18μm CMOS technology. The PA adopts the single-stage differential structure and the output power of the PA can be controlled by switching the sizes of transistors. Seven different level of output power can be obtained through a three- bit control code. The tested results shows that the proposed PA achieves power added efficiency (PAE of 26.73% while delivering an output power of 6.35dBm at 1dB compression point. Its power gain is 15.87dB. With a low DC voltage supply of 1V, its power consumption is 15.3mW. The PA die size is 1070×610μm2.

  14. Study of high power, two-stage, TWT X-band amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Wang, P.; Golkowski, C.; Hayashi, Y.; Ivers, J.D.; Nation, J.A.; Schachter, L.

    1999-07-01

    A disk loaded slow wave structure with a cold wave phase (without electron beam) velocity of the TM{sub 01} wave greater than the speed of light (1.05c) is used as the electron bunching stage of a two stage X-band amplifier. The high phase velocity section produces well defined electron bunches. The second section, where the cold wave phase velocity is (0.84c), i.e., less than beam velocity of 0.91c, is used to generate the high output power microwave radiation. The tightly bunched beam from the high phase velocity section enhances the beam energy conversion into microwave radiation compared to that obtained with a synchronous electron-wave bunches. The amplifier is driven by a 7mm diameter 750 kV, 500A pencil electron beam. The structure, which has a 4 GHz bandwidth, produces an amplified output with a power in the range of 20--60 MW. At higher output powers (>60MW) pulse shortening develops. The authors suspect that the pulse shortening is a result of excitation of the hybrid mode, HEM{sub 11}, which overlaps (about 0.5 GHz separation) with the frequency domain of the desired TM{sub 0.1} mode. A new amplifier with similar phase velocity characteristics but with a 1 GHz bandwidth and an HEM{sub 11}, TM{sub 01} mode frequency separation of 3.3 GHz has been designed and constructed. The interaction frequency for the HEM mode is above the passband of the TM mode. Testing is in progress. The performance of the new amplifier will be compared with results obtained using the earlier configuration.

  15. A 5.2 GHz RF combined power amplifier with fully integrated on-chip impedance matching Wilkinson power combiner and splitter

    OpenAIRE

    Kaymaksüt, Ercan; Kaymaksut, Ercan

    2008-01-01

    In this thesis a 5.2 GHz combined power amplifier is designed for Wireless Local Area Network (WLAN) application. A new on-chip power combining technique by using impedance matching Wilkinson power divider circuits will be presented. Two impedance matching Wilkinson power dividers are employed for matching the input and output impedances of the amplifier to 50 (omega)Ω as well as splitting the input power into two amplifiers and combining their output powers. A 5.2 GHz fully integrated class-...

  16. Area-Efficient 60 GHz +18.9 dBm Power Amplifier with On-Chip Four-Way Parallel Power Combiner in 65-nm CMOS

    Science.gov (United States)

    Farahabadi, Payam Masoumi; Basaligheh, Ali; Saffari, Parvaneh; Moez, Kambiz

    2017-02-01

    This paper presents a compact 60-GHz power amplifier utilizing a four-way on-chip parallel power combiner and splitter. The proposed topology provides the capability of combining the output power of four individual power amplifier cores in a compact die area. Each power amplifier core consists of a three-stage common-source amplifier with transformer-coupled impedance matching networks. Fabricated in 65-nm CMOS process, the measured gain of the 0.19-mm2 power amplifier at 60 GHz is 18.8 and 15 dB utilizing 1.4 and 1.0 V supply. Three-decibel band width of 4 GHz and P1dB of 16.9 dBm is measured while consuming 424 mW from a 1.4-V supply. A maximum saturated output power of 18.3 dBm is measured with the 15.9% peak power added efficiency at 60 GHz. The measured insertion loss is 1.9 dB at 60 GHz. The proposed power amplifier achieves the highest power density (power/area) compared to the reported 60-GHz CMOS power amplifiers in 65 nm or older CMOS technologies.

  17. Radar Waveform Pulse Analysis Measurement System for High-Power GaN Amplifiers

    Science.gov (United States)

    Thrivikraman, Tushar; Perkovic-Martin, Dragana; Jenabi, Masud; Hoffman, James

    2012-01-01

    This work presents a measurement system to characterize the pulsed response of high-power GaN amplifiers for use in space-based SAR platforms that require very strict amplitude and phase stability. The measurement system is able to record and analyze data on three different time scales: fast, slow, and long, which allows for greater detail of the mechanisms that impact amplitude and phase stability. The system is fully automated through MATLAB, which offers both instrument control capability and in-situ data processing. To validate this system, a high-power GaN HEMT amplifier operated in saturation was characterized. The fast time results show that variations to the amplitude and phase are correlated to DC supply transients, while long time characteristics are correlated to temperature changes.

  18. Augmented Twin-Nonlinear Two-Box Behavioral Models for Multicarrier LTE Power Amplifiers

    Directory of Open Access Journals (Sweden)

    Oualid Hammi

    2014-01-01

    Full Text Available A novel class of behavioral models is proposed for LTE-driven Doherty power amplifiers with strong memory effects. The proposed models, labeled augmented twin-nonlinear two-box models, are built by cascading a highly nonlinear memoryless function with a mildly nonlinear memory polynomial with cross terms. Experimental validation on gallium nitride based Doherty power amplifiers illustrates the accuracy enhancement and complexity reduction achieved by the proposed models. When strong memory effects are observed, the augmented twin-nonlinear two-box models can improve the normalized mean square error by up to 3 dB for the same number of coefficients when compared to state-of-the-art twin-nonlinear two-box models. Furthermore, the augmented twin-nonlinear two-box models lead to the same performance as previously reported twin-nonlinear two-box models while requiring up to 80% less coefficients.

  19. Wavelet network based predistortion method for wideband RF power amplifiers exhibiting memory effects

    Institute of Scientific and Technical Information of China (English)

    JIN Zhe; SONG Zhi-huan; HE Jia-ming

    2007-01-01

    RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques.Nevertheless, in wideband communication systems, PA memory effects can no longer be ignored and memoryless predistortion cannot linearize PAs effectively. After analyzing PA memory effects, a novel predistortion method based on wavelet networks (WNs) is proposed to linearize wideband RF power amplifiers. A complex wavelet network with tapped delay lines is applied to construct the predistorter and then a complex backpropagation algorithm is developed to train the predistorter parameters. The simulation results show that compared with the previously published feed-forward neural network predistortion method, the proposed method provides faster convergence rate and better performance in reducing out-of-band spectral regrowth.

  20. High Power Amplifiers Chain nonlinearity influence on the accelerating beam stability in free electron laser (FLASH)

    CERN Document Server

    Cichalewski, w

    2010-01-01

    The high power amplifiers transfer characteristics nonlinearities can have a negative influence on the overall system performance. This is also true for the TESLA superconducting cavities accelerating field parameters control systems. This Low Level Radio Frequency control systems uses microwave high power amplifiers (like 10 MW klystrons) as actuators in the mentioned feedback loops. The amplitude compression and phase deviations phenomena introduced to the control signals can reduce the feedback performance and cause electron beam energy instabilities. The transfer characteristics deviations in the Free Electron Laser in Hamburg experiment have been investigated. The outcome of this study together with the description of the developed linearization method based on the digital predistortion approach have been described in this paper. Additionally, the results from the linearization tool performance tests in the FLASH's RF systems have been placed.

  1. Augmented twin-nonlinear two-box behavioral models for multicarrier LTE power amplifiers.

    Science.gov (United States)

    Hammi, Oualid

    2014-01-01

    A novel class of behavioral models is proposed for LTE-driven Doherty power amplifiers with strong memory effects. The proposed models, labeled augmented twin-nonlinear two-box models, are built by cascading a highly nonlinear memoryless function with a mildly nonlinear memory polynomial with cross terms. Experimental validation on gallium nitride based Doherty power amplifiers illustrates the accuracy enhancement and complexity reduction achieved by the proposed models. When strong memory effects are observed, the augmented twin-nonlinear two-box models can improve the normalized mean square error by up to 3 dB for the same number of coefficients when compared to state-of-the-art twin-nonlinear two-box models. Furthermore, the augmented twin-nonlinear two-box models lead to the same performance as previously reported twin-nonlinear two-box models while requiring up to 80% less coefficients.

  2. Investigations of electronic amplifiers supplying a piezobimorph actuator

    Science.gov (United States)

    Milecki, Andrzej; Regulski, Roman

    2016-10-01

    Piezoelectric bending actuators, also known as bimorphs, are characterized by very good dynamic properties and by displacements in a range of a few millimeters. Therefore these actuators are used in a wide range of applications. However their usage is limited because they require supplying amplifiers with output voltage of about 200 V, which are rather expensive. This paper presents investigation results of such amplifiers with high voltage output. The model of a piezobending actuator is proposed and implemented in Matlab-Simulink software in order to simulate the behavior of the actuator supplied by the amplifiers. The simulation results are presented and compared with investigation results of high voltage amplifier used for supplying a piezoactuator. The influence of current limitation of operational amplifier on the actuator current is tested. Finally, a low cost audio power amplifier is proposed to control the piezobender actuator (as a cheaper alternative to the high-voltage amplifier) and its investigations results are presented in the paper.

  3. An efficient predistorter design for compensating nonlinear memory high power amplifier

    OpenAIRE

    2011-01-01

    This contribution applies digital predistorter to compensate distortions caused by memory high power amplifiers (HPAs) which exhibit true output saturation characteristics. Particle swarm optimization is first implemented to identify the Wiener HPA’s parameters. The estimated Wiener HPA model is then directly used to design the predistorter. The proposed digital predistorter solution is attractive owing to its low on-line computational complexity, small memory units required and simple VLSI h...

  4. All-fiber 194 W single-frequency single-mode Yb-doped master-oscillator power-amplifier

    Science.gov (United States)

    Mermelstein, M. D.; Brar, K.; Andrejco, M. J.; Yablon, A. D.; Fishteyn, M.; Headley, C., III; DiGiovanni, D. J.

    2008-02-01

    A four-stage all-fiber single-frequency single-mode continuous-wave (cw) master-oscillator power-amplifier (MOPA) at 1083 nm is presented. Small mode area (SMA) and large mode area (LMA) amplifier stages are mode matched with a fiber mode converter (MC) and the signal and pumps are combined with tapered fiber bundles (TFBs). The final power stage uses a LMA Yb doped SBS-suppressing fiber. A single-frequency output power of 194 W is demonstrated with optical net and slope efficiencies of 73% and 80%, respectively. Numerical simulations for the signal output power and the SBS-induced Stokes backscattered power in the 4th stage amplifier agree with the experimental results. Pulse amplifier measurements showed a 400 W peak power output that was limited by the forward output ASE. The SBS reflectivity at 400 W output was only 2.75 x 10 -4.

  5. Design and analysis of a highly-integrated CMOS power amplifier for RFID readers

    Institute of Scientific and Technical Information of China (English)

    Gao Tongqiang; Zhang Chun; Chi Baoyong; Wang Zhihua

    2009-01-01

    To implement a fully-integrated on-chip CMOS power amplifier (PA) for RFID readers, the resonant frequency of each matching network is derived in detail. The highlight of the design is the adoption of a bonding wire as the output-stage inductor. Compared with the on-chip inductors in a CMOS process, the merit of the bondwire inductor is its high quality factor, leading to a higher output power and efficiency. The disadvantage of the bondwire inductor is that it is hard to control. A highly integrated class-E PA is implemented with 0.18-μm CMOS process. It can provide a maximum output power of 20 dBm and a 1 dB output power of 14.5 dBm. The maximum power-added efficiency (PAE) is 32.1%. Also, the spectral performance of the PA is analyzed for the specified RFID protocol.

  6. Efficient power allocation for fixed-gain amplify-and-forward relaying in rayleigh fading

    KAUST Repository

    Zafar, Ammar

    2013-06-01

    In this paper, we study power allocation strategies for a fixed-gain amplify-and-forward relay network employing multiple relays. We consider two optimization problems for the relay network: 1) optimal power allocation to maximize the end-to-end signal-to-noise ratio (SNR) and 2) minimizing the total consumed power while maintaining the end-to-end SNR over a threshold value. We assume that the relays have knowledge of only the channel statistics of all the links. We show that the SNR maximization problem is concave and the power minimization problem is convex. Hence, we solve the problems through convex programming. Numerical results show the benefit of allocating power optimally rather than uniformly. © 2013 IEEE.

  7. Accurate geometry scalable complementary metal oxide semiconductor modelling of low-power 90 nm amplifier circuits

    Directory of Open Access Journals (Sweden)

    Apratim Roy

    2014-05-01

    Full Text Available This paper proposes a technique to accurately estimate radio frequency behaviour of low-power 90 nm amplifier circuits with geometry scalable discrete complementary metal oxide semiconductor (CMOS modelling. Rather than characterising individual elements, the scheme is able to predict gain, noise and reflection loss of low-noise amplifier (LNA architectures made with bias, active and passive components. It reduces number of model parameters by formulating dependent functions in symmetric distributed modelling and shows that simple fitting factors can account for extraneous (interconnect effects in LNA structure. Equivalent-circuit model equations based on physical structure and describing layout parasites are developed for major amplifier elements like metal–insulator–metal (MIM capacitor, spiral symmetric inductor, polysilicon (PS resistor and bulk RF transistor. The models are geometry scalable with respect to feature dimensions, i.e. MIM/PS width and length, outer-dimension/turns of planar inductor and channel-width/fingers of active device. Results obtained with the CMOS models are compared against measured literature data for two 1.2 V amplifier circuits where prediction accuracy for RF parameters (S(21, noise figure, S(11, S(22 lies within the range of 92–99%.

  8. Theoretical analysis of mode instability in high-power fiber amplifiers

    DEFF Research Database (Denmark)

    Hansen, Kristian Rymann; Alkeskjold, Thomas Tanggaard; Broeng, Jes;

    2013-01-01

    We present a simple theoretical model of transverse mode instability in high-power rare-earth doped fiber amplifiers. The model shows that efficient power transfer between the fundamental and higher-order modes of the fiber can be induced by a nonlinear interaction mediated through the thermo......-optic effect, leading to transverse mode instability. The temporal and spectral characteristics of the instability dynamics are investigated, and it is shown that the instability can be seeded by both quantum noise and signal intensity noise, while pure phase noise of the signal does not induce instability...

  9. The Design and Life Test of a Multifunction Power Amplifier for Space Application

    Directory of Open Access Journals (Sweden)

    Xiuqin Xu

    2016-01-01

    Full Text Available A new multifunction power amplifier (MFPA is designed and fabricated for the application of point-to-point K-Band backhaul TR module. A DC temperature life test was performed to model the up-limit temperature effect of the designed MFPA under space application. After 240 hours of 100°C life test, the test results illustrate that the designed MFPA has only slight power degradation at the saturation region without change of the linear gain. The general performance of the designed MFPA satisfies the requirement of the application scenario.

  10. Spectral Analysis of Polynomial Nonlinearity with Applications to RF Power Amplifiers

    Directory of Open Access Journals (Sweden)

    G. Tong Zhou

    2004-09-01

    Full Text Available The majority of the nonlinearity in a communication system is attributed to the power amplifier (PA present at the final stage of the transmitter chain. In this paper, we consider Gaussian distributed input signals (such as OFDM, and PAs that can be modeled by memoryless or memory polynomials. We derive closed-form expressions of the PA output power spectral density, for an arbitrary nonlinear order, based on the so-called Leonov-Shiryaev formula. We then apply these results to answer practical questions such as the contribution of AM/PM conversion to spectral regrowth and the relationship between memory effects and spectral asymmetry.

  11. 175-W continuous-wave master oscillator power amplifier structure ytterbium-doped all-fiber laser

    Institute of Scientific and Technical Information of China (English)

    Ping Yan; Shupeng Yin; Mali Gong

    2008-01-01

    We report on hundred watts range ytterbium-doped all-fiber laser assembly based on the master oscillator power amplifier structure. It consisted of an oscillator and an amplifier with all-fiber components. And fiber fusion splice made the laser be an integrated fiber system. It generated up to 175.5 W of continuouswave (CW) output power at 1085 nm with more than 75% extraction efficiency in the amplifier when the total coupled pump power into the double clad fiber was 270 W.

  12. High Power and Efficiency Space Traveling-Wave Tube Amplifiers With Reduced Size and Mass for NASA Missions

    Science.gov (United States)

    Simons, Rainee N.; Wilson, Jeffrey D.; Force, Dale A.

    2008-01-01

    Recent advances in high power and efficiency space traveling-wave tube amplifiers (TWTAs) for NASA s space-to-Earth communications are presented in this paper. The RF power and efficiency of a new K-Band amplifier are 40 W and 50 percent and that of a new Ka-Band amplifier are 200 W and 60 percent. An important figure-of-merit, which is defined as the ratio of the RF power output to the mass (W/kg) of a TWT has improved by a factor of ten over the previous generation Ka-Band devices.

  13. Wideband LTE power amplifier with integrated novel analog pre-distorter linearizer for mobile wireless communications.

    Directory of Open Access Journals (Sweden)

    Eswaran Uthirajoo

    Full Text Available For the first time, a new circuit to extend the linear operation bandwidth of a LTE (Long Term Evolution power amplifier, while delivering a high efficiency is implemented in less than 1 mm2 chip area. The 950 µm × 900 µm monolithic microwave integrated circuit (MMIC power amplifier (PA is fabricated in a 2 µm InGaP/GaAs process. An on-chip analog pre-distorter (APD is designed to improve the linearity of the PA, up to 20 MHz channel bandwidth. Intended for 1.95 GHz Band 1 LTE application, the PA satisfies adjacent channel leakage ratio (ACLR and error vector magnitude (EVM specifications for a wide LTE channel bandwidth of 20 MHz at a linear output power of 28 dBm with corresponding power added efficiency (PAE of 52.3%. With a respective input and output return loss of 30 dB and 14 dB, the PA's power gain is measured to be 32.5 dB while exhibiting an unconditional stability characteristic from DC up to 5 GHz. The proposed APD technique serves to be a good solution to improve linearity of a PA without sacrificing other critical performance metrics.

  14. Wideband LTE power amplifier with integrated novel analog pre-distorter linearizer for mobile wireless communications.

    Science.gov (United States)

    Uthirajoo, Eswaran; Ramiah, Harikrishnan; Kanesan, Jeevan; Reza, Ahmed Wasif

    2014-01-01

    For the first time, a new circuit to extend the linear operation bandwidth of a LTE (Long Term Evolution) power amplifier, while delivering a high efficiency is implemented in less than 1 mm2 chip area. The 950 µm × 900 µm monolithic microwave integrated circuit (MMIC) power amplifier (PA) is fabricated in a 2 µm InGaP/GaAs process. An on-chip analog pre-distorter (APD) is designed to improve the linearity of the PA, up to 20 MHz channel bandwidth. Intended for 1.95 GHz Band 1 LTE application, the PA satisfies adjacent channel leakage ratio (ACLR) and error vector magnitude (EVM) specifications for a wide LTE channel bandwidth of 20 MHz at a linear output power of 28 dBm with corresponding power added efficiency (PAE) of 52.3%. With a respective input and output return loss of 30 dB and 14 dB, the PA's power gain is measured to be 32.5 dB while exhibiting an unconditional stability characteristic from DC up to 5 GHz. The proposed APD technique serves to be a good solution to improve linearity of a PA without sacrificing other critical performance metrics.

  15. Econophysics of adaptive power markets: When a market does not dampen fluctuations but amplifies them.

    Science.gov (United States)

    Krause, Sebastian M; Börries, Stefan; Bornholdt, Stefan

    2015-07-01

    The average economic agent is often used to model the dynamics of simple markets, based on the assumption that the dynamics of a system of many agents can be averaged over in time and space. A popular idea that is based on this seemingly intuitive notion is to dampen electric power fluctuations from fluctuating sources (as, e.g., wind or solar) via a market mechanism, namely by variable power prices that adapt demand to supply. The standard model of an average economic agent predicts that fluctuations are reduced by such an adaptive pricing mechanism. However, the underlying assumption that the actions of all agents average out on the time axis is not always true in a market of many agents. We numerically study an econophysics agent model of an adaptive power market that does not assume averaging a priori. We find that when agents are exposed to source noise via correlated price fluctuations (as adaptive pricing schemes suggest), the market may amplify those fluctuations. In particular, small price changes may translate to large load fluctuations through catastrophic consumer synchronization. As a result, an adaptive power market may cause the opposite effect than intended: Power demand fluctuations are not dampened but amplified instead.

  16. GaN Power Stage for Switch-mode Audio Amplification

    DEFF Research Database (Denmark)

    Ploug, Rasmus Overgaard; Knott, Arnold; Poulsen, Søren Bang

    2015-01-01

    Gallium Nitride (GaN) based power transistors are gaining more and more attention since the introduction of the enhancement mode eGaN Field Effect Transistor (FET) which makes an adaptation from Metal-Oxide Semiconductor (MOSFET) to eGaN based technology less complex than by using depletion mode Ga...

  17. High-Power Amplifier Compatible Internally Sensed Optical Phased Array for Space Debris Tracking and Maneuvering

    Science.gov (United States)

    Roberts, L.; Francis, S.; Sibley, P.; Ward, R.; Smith, C.; McClelland, D.; Shaddock, D.

    2016-09-01

    Optical phased arrays (OPAs) provide a way to scale optical power beyond the capabilities of conventional CW lasers via coherent beam combination. By stabilising the relative output phase of multiple spatially separate lasers, OPAs form a coherent optical wavefront in the far field. Since the phase of each laser can be controlled independently, OPAs also have the ability to manipulate the distribution of optical power in the far field, and therefore may provide the capability to compensate for atmospheric turbulence. Combined with their inherent scalability and high power handling capabilities, OPAs are a promising technology for CW space debris ranging and manoeuvring. The OPA presented here is unique in its ability to sense the phase of each laser internally, without requiring any external sampling optics between it and the telescope. This allows the internally sensed OPA to be constructed entirely within fibre, utilising high-power fiber amplifiers to scale optical power beyond the limits of any conventional single lasers. The total power that can be delivered by each emitter in the OPA is limited only by the onset of stimulated Brillouin scattering, a non-linear effect that clamps the amount of power that can be delivered through a fiber waveguide. A three element internally sensed OPA developed at the Australian National University has been demonstrated to coherently combine three commercial 15 Watt fiber amplifiers with an output phase stability of one 200th of a wavelength. We have also demonstrated the ability to dynamically manipulate the distribution of optical power in the far-field at a bandwidth of up to 10 kHz. Since the OPA's control system is implemented using field-programmable gate-array technology, the system may be scaled beyond 100 emitters, potentially reaching the kilowatt level optical powers required to perturb the orbit of space debris.

  18. Modeling Distortion Effects in Class-D Amplifier Filter Inductors

    DEFF Research Database (Denmark)

    Knott, Arnold; Stegenborg-Andersen, Tore; Thomsen, Ole Cornelius

    2010-01-01

    Distortion is generally accepted as a quantifier to judge the quality of audio power amplifiers. In switchmode power amplifiers various mechanisms influence this performance measure. After giving an overview of those, this paper focuses on the particular effect of the nonlinearity of the output...... filter components on the audio performance. While the physical reasons for both, the capacitor and the inductor induced distortion are given, the practical in depth demonstration is done for the inductor only. This includes measuring the inductors performance, modeling through fitting and resulting...... into simulation models. The fitted models achieve distortion values between 0.03 % and 0.2 % as a basis to enable the design of a 200 W amplifier....

  19. A highly linear fully integrated CMOS power amplifier with an analog predistortion technique

    Energy Technology Data Exchange (ETDEWEB)

    Jin Boshi; Li Lewei; Wu Qun; Yang Guohui; Zhang Kuang, E-mail: boshijin@rdamicro.com [Department of Electronic and Communications Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-05-15

    A transformer-based CMOS power amplifier (PA) is linearized using an analog predistortion technique for a 2.5-GHz m-WiMAX transmitter. The third harmonic of the power stage and driver stage can be cancelled out in a specific power region. The two-stage PA fabricated in a standard 0.18-{mu}m CMOS process delivers 27.5 dBm with 27% PAE at the 1-dB compression point (P{sub 1dB}) and offers 21 dB gain. The PA achieves 5.5 % EVM and meets the spectrum mask at 20.5 dBm average power. Another conventional PA with a zero-cross-point of g{sub m3} bias is also fabricated and compared to prove its good linearity and efficiency. (semiconductor devices)

  20. Design of an Adaptive Predistorter for Solid State Power Amplifier in Wireless OFDM Systems

    Directory of Open Access Journals (Sweden)

    Rui J. P. de Figueiredo

    2009-01-01

    Full Text Available Orthogonal frequency division multiplexing (OFDM is a powerful modulation choice for wideband wireless communication systems. However, its high peak-to-average power ratio greatly limits the high power amplifier (HPA power efficiency. Here, we present the design of an adaptive predistorter to compensate the distortion caused by the HPA. Specifically, we deal with the implementation issue of the proposed predistorter in Lee and de Figueiredo's work (2006. The performance improvement by predistorter is verified by both floating-point simulation and fixed-point simulation, where the latter includes the distortion effects from the hardware. The bit widths for OFDM signals, ADC, and DAC are evaluated, and the bit width of 10 is shown to be sufficient for the hardware design.

  1. Small signal audio design

    CERN Document Server

    Self, Douglas

    2014-01-01

    Learn to use inexpensive and readily available parts to obtain state-of-the-art performance in all the vital parameters of noise, distortion, crosstalk and so on. With ample coverage of preamplifiers and mixers and a new chapter on headphone amplifiers, this practical handbook provides an extensive repertoire of circuits that can be put together to make almost any type of audio system.A resource packed full of valuable information, with virtually every page revealing nuggets of specialized knowledge not found elsewhere. Essential points of theory that bear on practical performance are lucidly

  2. Power-Combined GaN Amplifier with 2.28-W Output Power at 87 GHz

    Science.gov (United States)

    Fung, King Man; Ward, John; Chattopadhyay, Goutam; Lin, Robert H.; Samoska, Lorene A.; Kangaslahti, Pekka P.; Mehdi, Imran; Lambrigtsen, Bjorn H.; Goldsmith, Paul F.; Soria, Mary M.; Cooperrider, Joelle T.; Bruneau, Peter J.; Kurdoghlian, Ara; Micovic, Miroslav

    2011-01-01

    Future remote sensing instruments will require focal plane spectrometer arrays with higher resolution at high frequencies. One of the major components of spectrometers are the local oscillator (LO) signal sources that are used to drive mixers to down-convert received radio-frequency (RF) signals to intermediate frequencies (IFs) for analysis. By advancing LO technology through increasing output power and efficiency, and reducing component size, these advances will improve performance and simplify architecture of spectrometer array systems. W-band power amplifiers (PAs) are an essential element of current frequency-multiplied submillimeter-wave LO signal sources. This work utilizes GaN monolithic millimeter-wave integrated circuit (MMIC) PAs developed from a new HRL Laboratories LLC 0.15- m gate length GaN semiconductor transistor. By additionally waveguide power combining PA MMIC modules, the researchers here target the highest output power performance and efficiency in the smallest volume achievable for W-band.

  3. An on-chip temperature compensation circuit for an InGaP/GaAs HBT RF power amplifier

    Institute of Scientific and Technical Information of China (English)

    Li Chengzhan; Chen Zhijian; Huang Jiwei; Wang Yongping; Ma Chuanhui; Yang Hanbing; Liao Yinghao; Zhou Yong; Liu Bin

    2011-01-01

    A new on-chip temperature compensation circuit for a GaAs-based HBT RF amplifier applied to wireless communication is presented.The simple compensation circuit is composed of one GaAs HBT and five resistors with various values,which allow the power amplifier to achieve better thermal characteristics with a little degradation in performance.It effectively compensates for the temperature variation of the gain and the output power of the power amplifier by regulating the base quiescent bias current.The temperature compensation circuit is applied to a 3-stage integrated power amplifier for wireless communication applications,which results in an improvement in the gain variation from 4.0 to 1.1 dB in the temperature range between -20 and +80 ℃.

  4. High-Efficiency, Ka-band Solid-State Power Amplifier Utilizing GaN Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — QuinStar Technology proposes to develop an efficient, solid-state power amplifier (SSPA), operating at Ka-band frequencies, for high data rate, long range space...

  5. Materials physics and device development for improved efficiency of GaN HEMT high power amplifiers.

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Steven Ross; Follstaedt, David Martin; Wright, Alan Francis; Baca, Albert G.; Briggs, Ronald D.; Provencio, Paula Polyak; Missert, Nancy A.; Allerman, Andrew Alan; Marsh, Phil F.; Koleske, Daniel David; Lee, Stephen Roger; Shul, Randy John; Seager, Carleton Hoover; Tigges, Christopher P.

    2005-12-01

    GaN-based microwave power amplifiers have been identified as critical components in Sandia's next generation micro-Synthetic-Aperture-Radar (SAR) operating at X-band and Ku-band (10-18 GHz). To miniaturize SAR, GaN-based amplifiers are necessary to replace bulky traveling wave tubes. Specifically, for micro-SAR development, highly reliable GaN high electron mobility transistors (HEMTs), which have delivered a factor of 10 times improvement in power performance compared to GaAs, need to be developed. Despite the great promise of GaN HEMTs, problems associated with nitride materials growth currently limit gain, linearity, power-added-efficiency, reproducibility, and reliability. These material quality issues are primarily due to heteroepitaxial growth of GaN on lattice mismatched substrates. Because SiC provides the best lattice match and thermal conductivity, SiC is currently the substrate of choice for GaN-based microwave amplifiers. Obviously for GaN-based HEMTs to fully realize their tremendous promise, several challenges related to GaN heteroepitaxy on SiC must be solved. For this LDRD, we conducted a concerted effort to resolve materials issues through in-depth research on GaN/AlGaN growth on SiC. Repeatable growth processes were developed which enabled basic studies of these device layers as well as full fabrication of microwave amplifiers. Detailed studies of the GaN and AlGaN growth of SiC were conducted and techniques to measure the structural and electrical properties of the layers were developed. Problems that limit device performance were investigated, including electron traps, dislocations, the quality of semi-insulating GaN, the GaN/AlGaN interface roughness, and surface pinning of the AlGaN gate. Surface charge was reduced by developing silicon nitride passivation. Constant feedback between material properties, physical understanding, and device performance enabled rapid progress which eventually led to the successful fabrication of state of the

  6. Robust Power Allocation for Multi-Carrier Amplify-and-Forward Relaying Systems

    KAUST Repository

    Rao, Anlei

    2012-09-08

    It has been shown that adaptive power allocation can provide a substantial performance gain in wireless communication systems when perfect channel state information (CSI) is available at the transmitter. However when only imperfect CSI is available, the performance may degrade significantly, and as such robust power allocation schemes have been developed to minimize the effects of this degradation. In this paper, we investigate power allocation strategies for multicarrier systems, in which each subcarrier employs single amplify-and-forward (AF) relaying scheme. Optimal power allocation schemes are proposed by maximizing the approximated channel capacity under aggregate power constraint (APC) and separate power constraint (SPC). By comparison with the uniform power allocation scheme and the best channel power allocation scheme, we confirm that both the APC and SPC schemes achieve a performance gain over benchmark schemes. In addition, the impact of channel uncertainty is also considered in this paper by modeling the uncertainty regions as bounded sets, and results show that the uncertainty can degrade the worst- case performance significantly.

  7. 1.38 W tunable high-power narrow-linewidth external-cavity tapered amplifier at 670 nm

    DEFF Research Database (Denmark)

    Chi, Mingjun; Erbert, G.; Sumpf, B.;

    2010-01-01

    A diffraction-limited narrow-linewidth diode laser system based on a tapered amplifier in external cavity is demonstrated. 1.38 W output power is obtained. The laser system is tunable from 659 to 675 nm.......A diffraction-limited narrow-linewidth diode laser system based on a tapered amplifier in external cavity is demonstrated. 1.38 W output power is obtained. The laser system is tunable from 659 to 675 nm....

  8. First On-Wafer Power Characterization of MMIC Amplifiers at Sub-Millimeter Wave Frequencies

    Science.gov (United States)

    Fung, A. K.; Gaier, T.; Samoska, L.; Deal, W. R.; Radisic, V.; Mei, X. B.; Yoshida, W.; Liu, P. S.; Uyeda, J.; Barsky, M.; Lai, R.

    2008-01-01

    Recent developments in semiconductor technology have enabled advanced submillimeter wave (300 GHz) transistors and circuits. These new high speed components have required new test methods to be developed for characterizing performance, and to provide data for device modeling to improve designs. Current efforts in progressing high frequency testing have resulted in on-wafer-parameter measurements up to approximately 340 GHz and swept frequency vector network analyzer waveguide measurements to 508 GHz. On-wafer noise figure measurements in the 270-340 GHz band have been demonstrated. In this letter we report on on-wafer power measurements at 330 GHz of a three stage amplifier that resulted in a maximum measured output power of 1.78mW and maximum gain of 7.1 dB. The method utilized demonstrates the extension of traditional power measurement techniques to submillimeter wave frequencies, and is suitable for automated testing without packaging for production screening of submillimeter wave circuits.

  9. A fully integrated 3.5 GHz CMOS differential power amplifier driver

    Science.gov (United States)

    Xiaodong, Xu; Haigang, Yang; Tongqiang, Gao; Hongfeng, Zhang

    2013-07-01

    A fully integrated CMOS differential power amplifier driver (PAD) is proposed for WiMAX applications. In order to fulfill the differential application requirements, a transmission line transformer is used as the output matching network. A differential inductance constitutes an inter-stage matching network. Meanwhile, an on chip balun realizes input matching as well as single-end to differential conversion. The PAD is fabricated in a 0.13 μm RFCMOS process. The chip size is 1.1 × 1.1 mm2 with all of the matching network integrated on chip. The saturated power is around 10 dBm and power gain is about 12 dB.

  10. Study of a high power sine waveguide traveling wave tube amplifier centered at 8 GHz

    Science.gov (United States)

    Hoff, Brad W.; Simon, David S.; French, David M.; Lau, Y. Y.; Wong, Patrick

    2016-10-01

    Performance of a 20-stage X-band sine waveguide amplifier, driven by a 40 A, 100 kV, cylindrical electron beam, is studied using numerical simulation and interpreted using Pierce's classical traveling wave tube theory. For an input signal power level of 1.8 kW, particle-in-cell simulations predict gain and bandwidth values exceeding 14 dB and 13%, respectively. For an input signal power level of 7.2 kW, particle-in-cell simulations predict gain and bandwidth values exceeding 12 dB and 15%, respectively, with output power levels exceeding 110 kW at peak gain. Also given are: an assessment of the space charge factor (Pierce's QC parameter) for the complex circuit using simulation data, and an evaluation of the harmonic contents in the beam current.

  11. A Unified Distortion Analysis of Nonlinear Power Amplifiers with Memory Effects for OFDM Signals

    Science.gov (United States)

    Zhang, Yitao; Araki, Kiyomichi

    Nonlinear distortions in power amplifiers (PAs) generate spectral regrowth at the output, which causes interference to adjacent channels and errors in digitally modulated signals. This paper presents a novel method to evaluate adjacent channel leakage power ratio (ACPR) and error vector magnitude (EVM) from the amplitude-to-amplitude (AM/AM) and amplitude-to-phase (AM/PM) characteristics. The transmitted signal is considered to be complex Gaussian distributed in orthogonal frequency-division multiplexing (OFDM) systems. We use the Mehler formula to derive closed-form expressions of the PAs output power spectral density (PSD), ACPR and EVM for memoryless PA and memory PA respectively. We inspect the derived relationships using an OFDM signal in the IEEE 802.11a WLAN standard. Simulation results show that the proposed method is appropriate to predict the ACPR and EVM values of the nonlinear PA output in OFDM systems, when the AM/AM and AM/PM characteristics are known.

  12. Influence of core NA on Thermal-Induced Mode Instabilities in High Power Fiber Amplifiers

    CERN Document Server

    Tao, Rumao; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

    2015-01-01

    We report on the influence of core NA on thermal-induced mode instabilities (MI) in high power fiber amplifiers. Influence of core NA and V-parameter on MI has been investigated numerically. It shows that core NA has larger influence on MI for fibers with smaller core-cladding-ratio, and the influence of core NA on threshold is more obvious when the amplifiers are pumped at 915nm. The dependence of threshold on V-parameter revealed that the threshold increases linearly as V-parameter decreases when V-parameter is larger than 3.5, and the threshold shows exponentially increase as V-parameter decreases when V-parameter is less than 3.5. We also discussed the effect of linewidth on MI, which indicates that the influence of linewidth can be neglected for linewidth smaller than 1nm when the fiber core NA is smaller than 0.07 and fiber length is shorter than 20m. Fiber amplifiers with different core NA were experimentally analyzed, which agreed with the theoretical predictions.

  13. An ultra-low-power pulse oximeter implemented with an energy-efficient transimpedance amplifier.

    Science.gov (United States)

    Tavakoli, M; Turicchia, L; Sarpeshkar, R

    2010-02-01

    Pulse oximeters are ubiquitous in modern medicine to noninvasively measure the percentage of oxygenated hemoglobin in a patient's blood by comparing the transmission characteristics of red and infrared light-emitting diode light through the patient's finger with a photoreceptor. We present an analog single-chip pulse oximeter with 4.8-mW total power dissipation, which is an order of magnitude below our measurements on commercial implementations. The majority of this power reduction is due to the use of a novel logarithmic transimpedance amplifier with inherent contrast sensitivity, distributed amplification, unilateralization, and automatic loop gain control. The transimpedance amplifier, together with a photodiode current source, form a high-performance photoreceptor with characteristics similar to those found in nature, which allows LED power to be reduced. Therefore, our oximeter is well suited for portable medical applications, such as continuous home-care monitoring for elderly or chronic patients, emergency patient transport, remote soldier monitoring, and wireless medical sensing. Furthermore, our design obviates the need for an A-to-D and digital signal processor and leads to a small single-chip solution. We outline how extensions of our work could lead to submilliwatt oximeters.

  14. Optical Fiber Pumped High Repetition Rate and High Power Nd:YVO4 Picosecond Regenerative Amplifier

    Directory of Open Access Journals (Sweden)

    Zhen-Ao Bai

    2015-08-01

    Full Text Available We report a stable optical fiber pumped Nd:YVO4 all solid state regenerative amplifier with all fiber picosecond laser as seed source. 888 nm Yb optical fiber lasers was chosen as pump source to reduce quantum defect for improved thermal performance. At the repetition rate of 99.6 kHz, maximum power of 19.63 W with 36 ps pulse duration were achieved when seeded by a 150 mW picosecond oscillator. The wavelength delivered was 1064.07 nm with spectral width of 0.14 nm.

  15. Impact of Nonlinear Power Amplifier on Link Adaptation Algorithm of OFDM Systems

    DEFF Research Database (Denmark)

    Das, Suvra S.; Tariq, Faisal; Rahman, Muhammad Imadur

    2007-01-01

    The impact of non linear distortion due to High Power Amplifier (HPA) on the performance of Link Adaptation (LA) - Orthogonal Frequency Division Multiplexing (OFDM) based wireless system is analyzed. The performance of both Forward Error Control Coding (FEC) en-coded and uncoded system is evaluated....... LA maximizes the throughput while maintaining a required Block Error Rate (BLER). It is found that when OFDM signal, which has high PAPR, suffers non linear distortion due to non ideal HPA, the LA fails to meet the target BLER. Detailed analysis of the distortion and effects on LA are presented...

  16. High Power Er/Yb Codoped Double Clad Fiber Pulsed Amplifier Based on an All-Fiber Configuration

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lei; NING Ji-Ping; CHEN Cheng; HAN Qun; ZHANG Wei-Yi; WANG Jun-Tao

    2009-01-01

    We report an all-fiber two-stage high power pulsed amplifier,seeded with a 1550nm,1 kHz repetition rate rectangular pulse,and based on Er/Yb co-doped double clad fiber.All the characteristics are measured in the experiment.The maxima/slope efficiency is 22.56%,which is the highest we know of at such a low repetition rate,and the maximal output signal power is 1W.The various factors that affect the pulsed amplifier performance are analyzed.A high output power while keeping high power conversion efficiency can be obtained with careful selection of the input power,pump power and repetition rate.The experimental results show that the crucial parameters should be optimized when designing all-fiber pulsed amplifiers.

  17. A novel broadband power amplifier in SiGe HBT technology

    Institute of Scientific and Technical Information of China (English)

    Li Wenyuan; Zhang Qian

    2013-01-01

    A novel broadband power amplifier fabricated in 0.13 μm SiGe HBT technology is realized.The pseudo-differential structure is proposed to avoid the influence of the bonding wire due to the AC virtual ground created at the common emitter node.A compensated matching technique is adopted in interstage matching to expand bandwidth.A multi-stage broadband matching technique is used in an input/output matching network to offer broadband impedance matching,which ensures maximum power transfer.An adaptive bias circuit could improve linearity and efficiency in wide output power level.With 2.5 V power supply,the measured results achieve 96% 3-dB bandwidth (517-1470 MHz),27.2 dB power gain,26.9 dBm maximum output power,19.7 dBm output 1 dB compression point,and 26.7% power added efficiency.

  18. High power, continuous-wave, single frequency fiber amplifier at 1091 nm and frequency doubling to 545.5 nm

    CERN Document Server

    Stappel, M; Kolbe, D; Walz, J

    2012-01-01

    We present a high power single-frequency ytterbium fiber amplifier system with an output power of 30 W at 1091 nm. The amplifier system consists of two stages, a preamplifier stage in which amplified spontaneous emission is efficiently suppressed (>40 dB) and a high power amplifier with an efficiency of 52 %. Two different approaches of frequency doubling are compared. We achieve 8.6 W at 545.5 nm by single-pass frequency doubling in a MgO-doped periodically poled stoichiometric LiTaO3 and up to 19.3 W at 545.5 nm by frequency doubling with a lithium-triborate (LBO) crystal in an external enhancement cavity.

  19. 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

  20. A Low-Power 9-bit Pipelined CMOS ADC with Amplifier and Comparator Sharing Technique

    CERN Document Server

    Bocharov, Yuri; Osipov, Dmitry

    2012-01-01

    This paper describes a pipelined analog-to-digital converter (ADC) employing a power and area efficient architecture. The adjacent stages of a pipeline share operational amplifiers. In order to keep accuracy of the amplifiers in the first stages, they use a partially sharing technique. The feature of the proposed scheme is that it also shares the comparators. The capacitors of the first stages of a pipeline are scaled down along a pipeline for a further reducing the chip area and its power consumption. A 9-bit 20-MSamples/s ADC, intended for use in multi-channel mixed-signal chips, has been fabricated via Europractice in a 180-nm CMOS process from UMC. The prototype ADC shows a spurious-free dynamic range of 58.5 dB at a sample rate of 20 MSamples/s, when a 400 kHz input signal with a swing of 1 dB below full scale is applied. The effective number of bits is 8.0 at the same conditions. ADC occupies an active area of 0.4 mm2 and dissipates 8.6 mW at a 1.8 V supply.

  1. Editing Audio with Audacity

    Directory of Open Access Journals (Sweden)

    Brandon Walsh

    2016-08-01

    Full Text Available For those interested in audio, basic sound editing skills go a long way. Being able to handle and manipulate the materials can help you take control of your object of study: you can zoom in and extract particular moments to analyze, process the audio, and upload the materials to a server to compliment a blog post on the topic. On a more practical level, these skills could also allow you to record and package recordings of yourself or others for distribution. That guest lecture taking place in your department? Record it and edit it yourself! Doing so is a lightweight way to distribute resources among various institutions, and it also helps make the materials more accessible for readers and listeners with a wide variety of learning needs. In this lesson you will learn how to use Audacity to load, record, edit, mix, and export audio files. Sound editing platforms are often expensive and offer extensive capabilities that can be overwhelming to the first-time user, but Audacity is a free and open source alternative that offers powerful capabilities for sound editing with a low barrier for entry. For this lesson we will work with two audio files: a recording of Bach’s Goldberg Variations available from MusOpen and another recording of your own voice that will be made in the course of the lesson. This tutorial uses Audacity 2.1.2, released January 2016.

  2. An Integrated Low-Power Lock-In Amplifier and Its Application to Gas Detection

    Directory of Open Access Journals (Sweden)

    Paulina M. Maya-Hernández

    2014-08-01

    Full Text Available This paper presents a new micropower analog lock-in amplifier (LIA suitable for battery-operated applications thanks to its reduced size and power consumption as well as its operation with single-supply voltage. The proposed LIA was designed in a 0.18 µm CMOS process with a single supply voltage of 1.8 V. Experimental results show a variable DC gain ranging from 24.7 to 42 dB, power consumption of 417 µW and integration area of 0.013 mm2. The LIA performance was demonstrated by measuring carbon monoxide concentrations as low as 1 ppm in dry N2. The experimental results show that the response to CO of the sensing system can be considerably improved by means of the proposed LIA.

  3. Study of dopant concentrations on thermal induced mode instability in high power fiber amplifiers

    CERN Document Server

    Tao, Rumao; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

    2015-01-01

    Dependence of mode instabilities (MI) on ytterbium dopant concentrations in high power fiber amplifiers has been investigated. It is theoretically shown that, by only varying the fiber length to maintain the same total small-signal pump absorption, the MI threshold is independent of dopant concentration. MI thresholds of gain fibers with ytterbium dopant concentration of 5.93X10^25/m3 and 1.02X10^26/m3 have been measured, which exhibit similar thresholds and agree with theoretical results. The result indicates that heavy doping of active fiber can be adopted to suppress nonlinear effects without decreasing MI threshold, which provides a method of maximizing the power output of fiber laser, taking into account the stimulated Brillouin scattering, stimulated Raman Scattering, and MI thresholds simultaneously.

  4. An integrated low-power lock-in amplifier and its application to gas detection.

    Science.gov (United States)

    Maya-Hernández, Paulina M; Álvarez-Simón, Luis C; Sanz-Pascual, María Teresa; Calvo-López, Belén

    2014-08-27

    This paper presents a new micropower analog lock-in amplifier (LIA) suitable for battery-operated applications thanks to its reduced size and power consumption as well as its operation with single-supply voltage. The proposed LIA was designed in a 0.18 µm CMOS process with a single supply voltage of 1.8 V. Experimental results show a variable DC gain ranging from 24.7 to 42 dB, power consumption of 417 µW and integration area of 0.013 mm2. The LIA performance was demonstrated by measuring carbon monoxide concentrations as low as 1 ppm in dry N2. The experimental results show that the response to CO of the sensing system can be considerably improved by means of the proposed LIA.

  5. A Wideband Digital Predistorter for a Doherty Power Amplifier Using a Direct Learning Memory Effect Filter

    Science.gov (United States)

    Horiguchi, Kenichi; Matsunaga, Naoko; Yamauchi, Kazuhisa; Hayashi, Ryoji; Miyazaki, Moriyasu; Nojima, Toshio

    This paper presents a digital predistorter with a wideband memory effect compensator for a Doherty power amplifier (PA). A simple memory-predistortion model, which consists of a look-up-table (LUT) and an adaptive filter equalizing memory effects, and a new memory effect estimation algorithm using a direct-learning architecture are proposed. The proposed estimation algorithm has an advantage that a transfer function of a feedback circuit does not affect the learning process. The predistorter is implemented in a field programmable gate array (FPGA) and a digital signal processor (DSP). The transmitter has achieved distortion level of -50.8dBr at signal bandwidth away from the carrier, and PA module efficiency of 24% with output power of 43dBm at 2595MHz under a 20MHz-bandwidth orthogonal frequency division multiplexing (OFDM) signal using laterally diffused metal oxide semiconductor (LDMOS) FETs.

  6. A 3-5 GHz CMOS UWB power amplifier with {+-}8 ps group delay ripple

    Energy Technology Data Exchange (ETDEWEB)

    Xi Tianzuo; Huang Lu; Zheng Zhong; Feng Lisong, E-mail: xitianzuo@hotmail.co [Department of Electronic Science and Technology, University of Science and Technology of China, Hefei 230027 (China)

    2010-04-15

    A differential power amplifier (PA), designed using the linear-phase filter model, for a BPSK modulated ultra-wideband (UWB) system operating in the 3-5 GHz frequency range is presented. The proposed PA was fabricated using 0.18 {mu}m SMIC CMOS technology. To achieve sufficient linearity and efficiency, this PA operates in the class-AB region, delivering an output power of 8.5 dBm at an input-1 dB compression point of -0.5 dBm. It consumes 28.8 mW, realizing a flat gain of 9.11 {+-} 0.39 dB and a very low group delay ripple of {+-}8 ps across the whole band of operation. (semiconductor integrated circuits)

  7. Optimal power allocation to minimize SER for multinode amplify-and-forward cooperative communication systems

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An optimal power allocation (OPA) method with mean channel gains is proposed for a multinode amplify-and-forward cooperative communication system. By making use of M-PSK modulation, a closed-form symbol-error-rate (SER) formulation and corresponding upper bound are first derived. Subsequently the OPA method is utilized to minimize the SER. Comparison of the SER of the proposed OPA method with that of the equal power allocation (EPA) method, shows that the SER of both methods, which is approximately optimal performance, is almost the same when relays are near the source. OPA outperforms the EPA when the relays are near the middle between the source and destination or near the destination. The proposed OPA method depends only on the ratio of mean channel gains of the source-to-relay to those of the relay-to-destination. Extensive simulations are performed to validate the theoretical results.

  8. Modeling Nonlinear Power Amplifiers in OFDM Systems from Subsampled Data: A Comparative Study Using Real Measurements

    Directory of Open Access Journals (Sweden)

    Santamaría Ignacio

    2003-01-01

    Full Text Available A comparative study among several nonlinear high-power amplifier (HPA models using real measurements is carried out. The analysis is focused on specific models for wideband OFDM signals, which are known to be very sensitive to nonlinear distortion. Moreover, unlike conventional techniques, which typically use a single-tone test signal and power measurements, in this study the models are fitted using subsampled time-domain data. The in-band and out-of-band (spectral regrowth performances of the following models are evaluated and compared: Saleh's model, envelope polynomial model (EPM, Volterra model, the multilayer perceptron (MLP model, and the smoothed piecewise-linear (SPWL model. The study shows that the SPWL model provides the best in-band characterization of the HPA. On the other hand, the Volterra model provides a good trade-off between model complexity (number of parameters and performance.

  9. Maximally Flat Waveforms with Finite Number of Harmonics in Class-F Power Amplifiers

    Directory of Open Access Journals (Sweden)

    Anamarija Juhas

    2013-01-01

    Full Text Available In this paper general solution to the problem of finding maximally flat waveforms with finite number of harmonics (maximally flat trigonometric polynomials is provided. Waveform coefficients are expressed in closed form as functions of harmonic orders. Two special cases of maximally flat waveforms (so-called maximally flat even harmonic and maximally flat odd harmonic waveforms, which proved to play an important role in class-F and inverse class-F power amplifier (PA operations, are also considered. For these two special types of waveforms, coefficients are expressed as functions of two parameters only. Closed form expressions for efficiency and power output capability of class-F and inverse class-F PA operations with maximally flat waveforms are also provided as explicit functions of number of a harmonics.

  10. Simultaneous Wireless Information and Power Transfer for MIMO Amplify-and-Forward Relay Systems

    KAUST Repository

    Benkhelifa, Fatma

    2016-03-28

    © 2015 IEEE. In this paper, we investigate two-hop Multiple- Input Multiple-Output (MIMO) Amplify-and-Forward (AF) relay communication systems with simultaneous wireless information and power transfer (SWIPT) at the multi-antenna energy harvesting relay. We derive the optimal source and relay covariance matrices to characterize the achievable region between the source-destination rate and the harvested energy at the relay, namely Rate-Energy (R-E) region. In this context, we consider the ideal scenario where the energy harvester (EH) receiver and the information decoder (ID) receiver at the relay can simultaneously decode the information and harvest the energy at the relay. This scheme provides an outer bound for the achievable R-E region since practical energy harvesting circuits are not yet able to harvest the energy and decode the information simultaneously. Then, we consider more practical schemes which are the power splitting (PS) and the time switching (TS) proposed in [1] and which separate the EH and ID transfer over the power domain and the time domain, respectively. In our study, we derive the boundary of the achievable R- E region and we show the effect of the source transmit power, the relay transmit power and the position of the relay between the source and the destination on the achievable R-E region for the ideal scenario and the two practical schemes.

  11. Low-Loss Matching Network Design for Band-Switchable Multi-Band Power Amplifier

    Science.gov (United States)

    Fukuda, Atsushi; Furuta, Takayuki; Okazaki, Hiroshi; Narahashi, Shoichi; Nojima, Toshio

    This paper presents a novel design scheme for a band-switchable multi-band power amplifier (BS-MPA). A key point of the design scheme is configuring multi-section reconfigurable matching networks (MR-MNs) optimally in terms of low loss matching in multiple frequency bands from 0.7 to 2.5GHz. The MR-MN consists of several matching sections, each of which has a matching block connected to a transmission line via a switch. Power dissipation at an actual on-state switch results in the insertion loss of the MR-MN and depends on how the impedance is transformed by the MR-MN. The proposed design scheme appropriately transforms the impedance of a high power transistor to configure a low loss MR-MN. Numerical analyses show quantitative improvement in the loss using the proposed scheme. A 9-band 3-stage BS-MPA is newly designed following the proposed scheme and fabricated on a multi-layer low temperature co-fired ceramic substrate for compactness. The BS-MPA achieves a gain of over 30dB, an output power of greater than 33dBm and a power added efficiency of over 40% at the supply voltage of 4V in each operating band.

  12. Joint Subchannel Pairing and Power Control for Cognitive Radio Networks with Amplify-and-Forward Relaying

    Science.gov (United States)

    Shen, Yanyan; Wang, Shuqiang; Wei, Zhiming

    2014-01-01

    Dynamic spectrum sharing has drawn intensive attention in cognitive radio networks. The secondary users are allowed to use the available spectrum to transmit data if the interference to the primary users is maintained at a low level. Cooperative transmission for secondary users can reduce the transmission power and thus improve the performance further. We study the joint subchannel pairing and power allocation problem in relay-based cognitive radio networks. The objective is to maximize the sum rate of the secondary user that is helped by an amplify-and-forward relay. The individual power constraints at the source and the relay, the subchannel pairing constraints, and the interference power constraints are considered. The problem under consideration is formulated as a mixed integer programming problem. By the dual decomposition method, a joint optimal subchannel pairing and power allocation algorithm is proposed. To reduce the computational complexity, two suboptimal algorithms are developed. Simulations have been conducted to verify the performance of the proposed algorithms in terms of sum rate and average running time under different conditions. PMID:25045731

  13. High average power picosecond pulse and supercontinuum generation from a thulium-doped, all-fiber amplifier.

    Science.gov (United States)

    Liu, Jiang; Xu, Jia; Liu, Kun; Tan, Fangzhou; Wang, Pu

    2013-10-15

    We demonstrate a high-power, picosecond, thulium-doped, all-fiber master oscillator power amplifier with average power of 120.4 W. The compact fiber oscillator is carefully designed with high repetition rate for the purpose of overcoming the detrimental effects of fiber nonlinearity in the later fiber amplifiers. The pulse duration of 16 ps at 333.75 MHz repetition rate results in a peak power of 22.5 kW in the final fiber power amplifier. To the best of our knowledge, this is the first demonstration of average power exceeding 100 W from an ultrashort pulse laser at 2 μm wavelength. On the other hand, by decreasing the fiber oscillator repetition rate and pulse duration for enhancing the fiber nonlinearity effects, we also demonstrate a high-power supercontinuum source with average power of 36 W from 1.95 μm to beyond 2.4 μm in the final fiber power amplifier.

  14. Balancing Audio

    DEFF Research Database (Denmark)

    Walther-Hansen, Mads

    2016-01-01

    This paper explores the concept of balance in music production and examines the role of conceptual metaphors in reasoning about audio editing. Balance may be the most central concept in record production, however, the way we cognitively understand and respond meaningfully to a mix requiring balance...... is not thoroughly understood. In this paper I treat balance as a metaphor that we use to reason about several different actions in music production, such as adjusting levels, editing the frequency spectrum or the spatiality of the recording. This study is based on an exploration of a linguistic corpus of sound...

  15. Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission

    Science.gov (United States)

    Sullivan, Gerry

    2001-01-01

    For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

  16. 94 GHz power amplifier MMIC development in state of the art MHEMT and AlGaN/GaN technology

    NARCIS (Netherlands)

    Heijningen, M. van; Bent, G. van der; Rodenburg, M.; Vliet, F.E. van; Quay, R.; Brückner, P.; Schwantuschke, D.; Jukkala, P.; Narhi, T.

    2012-01-01

    Solid-state power amplifiers at W-band (75 - 110 GHz) are attractive for the generation of local-oscillator (LO) power for super-heterodyne receivers operating at sub-millimetre wave frequencies, as needed for example in future space instruments for Earth observation. Apart from space applications t

  17. Design and Analysis of a 34 dBm Ka-Band GaN High Power Amplifier MMIC

    NARCIS (Netherlands)

    Heijningen, M. van; Vliet, F.E. van; Quay, R.; Raay, F. van; Seelmann-Eggebert, M.

    2006-01-01

    This paper presents the design and analysis issues related to the use of recent GaN technologies for realizing high power millimeter wave MMICs. Two GaN Ka-band amplifier MMICs have been designed, fabricated and characterized. The small-signal and power measurement results are presented for both amp

  18. Design of InP DHBT power amplifiers at millimeter-wave frequencies using interstage matched cascode technique

    DEFF Research Database (Denmark)

    Yan, Lei; Johansen, Tom Keinicke

    2013-01-01

    In this paper, the design of InP DHBT based millimeter-wave(mm-wave) power amplifiers(PAs) using an interstage matched cascode technique is presented. The output power of a traditional cascode is limited by the early saturation of the common-base(CB) device. The interstage matched cascode can be ...

  19. Design of High-Voltage Switch-Mode Power Amplifier Based on Digital-Controlled Hybrid Multilevel Converter

    Directory of Open Access Journals (Sweden)

    Yanbin Hou

    2016-01-01

    Full Text Available Compared with conventional Class-A, Class-B, and Class-AB amplifiers, Class-D amplifier, also known as switching amplifier, employs pulse width modulation (PWM technology and solid-state switching devices, capable of achieving much higher efficiency. However, PWM-based switching amplifier is usually designed for low-voltage application, offering a maximum output voltage of several hundred Volts. Therefore, a step-up transformer is indispensably adopted in PWM-based Class-D amplifier to produce high-voltage output. In this paper, a switching amplifier without step-up transformer is developed based on digital pulse step modulation (PSM and hybrid multilevel converter. Under the control of input signal, cascaded power converters with separate DC sources operate in PSM switch mode to directly generate high-voltage and high-power output. The relevant topological structure, operating principle, and design scheme are introduced. Finally, a prototype system is built, which can provide power up to 1400 Watts and peak voltage up to ±1700 Volts. And the performance, including efficiency, linearity, and distortion, is evaluated by experimental tests.

  20. Silicon Carbide MOSFET-Based Switching Power Amplifier for Precision Magnet Control

    Science.gov (United States)

    Miller, Kenneth; Ziemba, Timothy; Prager, James; Picard, Julian

    2016-10-01

    Eagle Harbor Technologies, Inc. (EHT) is using the latest in solid-state switching technologies to advance the state-of-the-art in magnet control for fusion science. Silicon carbide (SiC) MOSFETs offer advantages over IGBTs including lower drive energy requirements, lower conduction and switching losses, and higher switching frequency capabilities. When comparing SiC and traditional silicon-based MOSFETs, SiC MOSFETs provide higher current carrying capability allowing for smaller package weights and sizes and lower operating temperature. To validate the design, EHT has developed a low-power switching power amplifier (SPA), which has been used for precision control of magnetic fields, including rapidly changing the fields in coils. This design has been incorporated in to a high power SPA, which has been bench tested. This high power SPA will be tested at the Helicity Injected Torus (HIT) at the University of Washington. Following successful testing, EHT will produce enough SiC MOSFET-based SPAs to replace all of the units at HIT, which allows for higher frequency operation and an overall increase in pulsed current levels.

  1. SEMICONDUCTOR INTEGRATED CIRCUITS A 900 MHz, 21 dBm CMOS linear power amplifier with 35% PAE for RFID readers

    Science.gov (United States)

    Kefeng, Han; Shengguo, Cao; Xi, Tan; Na, Yan; Junyu, Wang; Zhangwen, Tang; Hao, Min

    2010-12-01

    A two-stage differential linear power amplifier (PA) fabricated by 0.18 μm CMOS technology is presented. An output matching and harmonic termination network is exploited to enhance the output power, efficiency and harmonic performance. Measurements show that the designed PA reaches a saturated power of 21.1 dBm and the peak power added efficiency (PAE) is 35.4%, the power gain is 23.3 dB from a power supply of 1.8 V and the harmonics are well controlled. The total area with ESD protected PAD is 1.2 × 0.55 mm2. System measurements also show that this power amplifier meets the design specifications and can be applied for RFID reader.

  2. Optimized Envelope Tracking Power Supply for Tetra2 Base Station RF Power Amplifier

    DEFF Research Database (Denmark)

    Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

    2008-01-01

    An ultra-fast tracking power supply (UFTPS) for envelope tracking in a 50kHz 64-QAM Tetra2 base station power amplification system is demonstrated. A simple method for optimizing the step response of the PID+PD sliding-mode control system is presented and demonstrated, along with a PLL-based scheme...... for locking the switching frequency to an external clock. High UFTPS efficiency (up to 95%), very low ripple (5mVpp) and a fast step response (10μs) are obtained from a single-phase buck converter with a 4th-order output filter. This ripple performance is demonstrated to be critical in the considered...

  3. A Ku band internally matched high power GaN HEMT amplifier with over 30%of PAE

    Institute of Scientific and Technical Information of China (English)

    Ge Qin; Chen Xiaoiuan; Luo Weijun; Yuan Tingting; Pu Yan; Liu Xinyu

    2012-01-01

    We report a high power Ku band internally matched power amplifier (IMPA) with high power added efficiency (PAE) using 0.3 μm AlGaN/GaN high electron mobility transistors (HEMTs) on 6H-SiC substrate.The internal matching circuit is designed to achieve high power output for the developed devices with a gate width of 4 mm.To improve the bandwidth of the amplifier,a T type pre-matching network is used at the input and output circuits,respectively.After optimization by a three-dimensional electromagnetic (3D-EM) simulator,the amplifier demonstrates a maximum output power of 42.5 dBm (17.8 W),PAE of 30% to 36.4% and linear gain of 7 to 9.3 dB over 13.8-14.3 GHz under a 10% duty cycle pulse condition when operated at Vds =30 V and Vgs =-4 V.At such a power level and PAE,the amplifier exhibits a power density of 4.45 W/mm.

  4. A Ku band internally matched high power GaN HEMT amplifier with over 30% of PAE

    Science.gov (United States)

    Qin, Ge; Xiaojuan, Chen; Weijun, Luo; Tingting, Yuan; Yan, Pu; Xinyu, Liu

    2012-01-01

    We report a high power Ku band internally matched power amplifier (IMPA) with high power added efficiency (PAE) using 0.3 μm AlGaN/GaN high electron mobility transistors (HEMTs) on 6H-SiC substrate. The internal matching circuit is designed to achieve high power output for the developed devices with a gate width of 4 mm. To improve the bandwidth of the amplifier, a T type pre-matching network is used at the input and output circuits, respectively. After optimization by a three-dimensional electromagnetic (3D-EM) simulator, the amplifier demonstrates a maximum output power of 42.5 dBm (17.8 W), PAE of 30% to 36.4% and linear gain of 7 to 9.3 dB over 13.8-14.3 GHz under a 10% duty cycle pulse condition when operated at Vds = 30 V and Vgs = -4 V. At such a power level and PAE, the amplifier exhibits a power density of 4.45 W/mm.

  5. Study on Volterra-Laguerre behavioral model for RF power amplifier

    Institute of Scientific and Technical Information of China (English)

    Nan Jingchang; Liu Yuanan; Tang Bihua

    2007-01-01

    Volterra series behavioral model for radio frequency(RF)power amplifier(PA)has been widely used in system-level simulation,however,high computational complexity makes this kind of model limited to"weak"nonlinearity.In order to reduce the computational complexity and the number of coefficients of Volterra series kernels,a Volterra series improved behavioral model based on Lasuerre orthogonal polynomials function,namely Volterra-Laguerre behavioral model,is proposed.Mathematical expressions of Volterra-Laguerre behavioral model is derived.and accuracy of the model is verified through comparison of measured and simulation output data from a freescale PA using MRF21030 transistor.Mathematical analysis and simulation results show that Volterra-Laguerre behavioral model has a simple structure,much less coefficients and better modeling performance than general Volterra series model.The model can be used more correctly for system-level simulation of RF PA with wideband signal.

  6. Volterra series based predistortion for broadband RF power amplifiers with memory effects

    Institute of Scientific and Technical Information of China (English)

    Jin Zhe; Song Zhihuan; He Jiaming

    2008-01-01

    RF power amplifiers(PAs)are usually considered as memoryless devices in most existing predistortion techniques.However,in broadband communication systems,such as WCDMA,the PA memory effects are significant,and memoryless predistortion cannot linearize the PAs effectively.After analyzing the PA memory effects,a novel predistortion method based on the simplified Volterra series is proposed to linearize broadband RF PAs with memory effects.The indirect learning architecture is adopted to design the predistortion scheme and the recursive least squares algorithm with forgetting factor is applied to identify the parameters of the predistorter.Simulation results show that the proposed predistortion method can compensate the nonlinear distortion and memory effects of broadband RF PAs effectively.

  7. Electronically Tunable Impedance-Matching Networks for Intelligent RF Power Amplifiers

    Directory of Open Access Journals (Sweden)

    Liang Li

    2013-11-01

    Full Text Available This paper presents the simulation and optimization design of the electronically tunable impedance-matching networks for intelligent RF power amplifiers in a cognitive radio system. Reconfigurable elements, such as varactors and RF switches are utilized to achieve the dynamic impedance matching both in the input and output matching circuit, providing coarse and fine tuning of the target impedances with low loss and excellent impedance coverage from 500MHz to 800MHz. The topology of varactor model is illustrated to ensure the precision of simulation. In addition, high-precision bias voltage controlling system is designed to improve the nonlinear problem caused by the varactor. The simulation results demonstrate the excellent performance of the tunable networks, satisfying the requirement of the cognitive radio systems.  

  8. Self-heating and memory effects in RF power amplifiers explained through electro-thermal

    DEFF Research Database (Denmark)

    Wei, Wei; Jensen, Ole Kiel; Mikkelsen, Jan H.

    2013-01-01

    Self-heating has already been proven to be one of the key sources to memory effects in RF power amplifiers (PAs). However, mechanisms behind the generation of memory effects, as caused by self-heating have not been well documented. On basis of transistor physical properties this paper proposes...... a simple electro-thermal model and shows how self-heating can generate different types of memory effects, such as bandwidth dependent intermodulation components and hysteresis loops. In addition, it is shown that self-heating can result in generation of new spectral components even in an otherwise linear...... PA. A time domain modeling framework is implemented to investigate memory effects generated by self-heating and simulation results are shown to agree with theoretical analysis....

  9. Adaptive Digital Predistortion Schemes to Linearize RF Power Amplifiers with Memory Effects

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; WU Si-liang; ZHANG Qin

    2008-01-01

    To compensate for nonlinear distortion introduced by RF power amplifiers (PAs) with memory effects, two correlated models, namely an extended memory polynomial (EMP) model and a memory lookup table (LUT) model, are proposed for predistorter design. Two adaptive digital predistortion (ADPD) schemes with indirect learning architecture are presented. One adopts the EMP model and the recursive least square (RLS) algorithm, and the other utilizes the memory LUT model and the least mean square (LMS) algorithm. Simulation results demonstrate that the EMP-based ADPD yields the best linearization performance in terms of suppressing spectral regrowth. It is also shown that the ADPD based on memory LUT makes optimum tradeoff between performance and computational complexity.

  10. Numerical Analysis of a Cold Plate for FM Radio Power Amplifiers

    Science.gov (United States)

    Sabin, M.; Piva, S.

    2014-07-01

    The results of a numerical investigation of heat and fluid flow in a liquid cold plate for FM radio power amplifiers are presented. The objective is to verify, by using a commercial CFD code, the performance of a blister cold plate designed to dissipate the heat generated by a known set of electronic components, in order to limit their maximum temperature during operations. Since in a blister cold-plate mainly the cover is thermally active, the cold-plate is simplified and lightened by using plastics in the base plate. A 3-D conjugate CFD approach, where thermal and fluid flow analyses are combined, is followed. Several design options for the cold plate are examined and the validity of the full 3-D CFD approach in the dimensioning of the cooling systems of electronic equipment is demonstrated.

  11. 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...

  12. Optimizing high-power Yb-doped fiber amplifier systems in the presence of transverse mode instabilities.

    Science.gov (United States)

    Jauregui, Cesar; Otto, Hans-Jürgen; Breitkopf, Sven; Limpert, J; Tünnermann, A

    2016-04-18

    The average output power of Yb-doped fiber amplifier systems is currently limited by the onset of transverse mode instabilities. Besides, it has been recently shown that the transverse mode instability threshold can be significantly reduced by the presence of photodarkening in the fiber. Therefore, reducing the photodarkening level of the core material composition is the most straightforward way to increase the output average power of fiber amplifier systems but, unfortunately, this is not always easy or possible. In this paper we present guidelines to optimize the output average power of fiber amplifiers affected by transverse mode instabilities and photodarkening. The guidelines derived from the simulations do not involve changes in the composition of the active material (except for its doping concentration), but can still lead to a significant increase of the transverse mode instability threshold. The dependence of this parameter on the active ion concentration and the core conformation, among others, will be studied and discussed.

  13. Design of Predistorter with Efficient Updating Algorithm of Power Amplifier with Memory Effect

    Science.gov (United States)

    Oishi, Yasuyuki; Kimura, Shigekazu; Fukuda, Eisuke; Takano, Takeshi; Takago, Daisuke; Daido, Yoshimasa; Araki, Kiyomichi

    This paper describes a method to design a predistorter (PD) for a GaN-FET power amplifier (PA) by using nonlinear parameters extracted from measured IMD which has asymmetrical peaks peculiar to a memory effect with a second-order lag. While, computationally efficient equations have been reported by C. Rey et al. for the memory effect with a first-order lag. Their equations are extended to be applicable to the memory effect with the second-order lag. The extension provides a recursive algorithm for cancellation signals of the PD each of which updating is made by using signals in only two sampling points. The algorithm is equivalent to a memory depth of two in computational efficiency. The required times for multiplications and additions are counted for the updating of all the cancellation signals and it is confirmed that the algorithm reduces computational intensity lower than half of a memory polynomial in recent papers. A computer simulation has clarified that the PD improves the adjacent channel leakage power ratio (ACLR) of OFDM signals with several hundred subcarriers corresponding to 4G mobile radio communications. It has been confirmed that a fifth-order PD is effective up to a higher power level close to 1dB compression. The improvement of error vector magnitude (EVM) by the PD is also simulated for OFDM signals of which the subcarrier channels are modulated by 16 QAM.

  14. Low-Power Amplifier-Discriminators for High Time Resolution Detection

    CERN Document Server

    Despeisse, M; Anghinolfi, F; Tiuraniemi, S; Osmic, F; Riedler, P; Kluge, A; Ceccucci, A

    2009-01-01

    Low-power amplifier-discriminators based on a so-called NINO architecture have been developed with high time resolution for the readout of radiation detectors. Two different circuits were integrated in the NINO13 chip, processed in IBM 130 nm CMOS technology. The LCO version (Low Capacitance and consumption Optimization) was designed for potential use as front-end electronics in the Gigatracker of the NA62 experiment at CERN. It was developed as pixel readout for solid-state pixel detectors to permit minimum ionizing particle detection with less than 180 ps rms resolution per pixel on the output pulse, for power consumption below 300 mu W per pixel. The HCO version (High Capacitance Optimization) was designed with 4 mW power consumption per channel to provide timing resolution below 20 ps rms on the output pulse, for charges above 10 fC. Results presented show the potential of the LCO and HCO circuits for the precise timing readout of solid-state detectors, vacuum tubes or gas detectors, for applications in h...

  15. High Power SiGe X-Band (8~10GHz) Heterojunction Bipolar Transistors and Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Limited by increased parasitics and thermal effects as device size increases, current commercial SiGe power HBTs are difficult to operate at X-band (8~ 12GHz) frequencies with adequate power added efficiencies at high power levels. We find that, by changing the heterostructure and doping profile of SiGe HBTs, their power gain can be significantly improved without resorting to substantial lateral scaling. Furthermore, employing a common-base configuration with a proper doping profile instead of a common-emitter configuration improves the power gain characteristics of SiGe HBTs, thus permitting these devices to be efficiently operated at X-band frequencies. In this paper,we report the results of SiGe power HBTs and MMIC power amplifiers operating at 8~10GHz. At 10GHz,a 22.5dBm (178mW) RF output power with a concurrent gain of 7.32dB is measured at the peak power-added efficiency of 20.0%, and a maximum RF output power of 24.0dBm (250mW) is achieved from a 20 emitter finger SiGe power HBT. The demonstration of a single-stage X-band medium-power linear MMIC power amplifier is also realized at 8GHz. Employing a 10-emitter finger SiGe HBT and on-chip input and output matching passive components, a linear gain of 9.7dB,a maximum output power of 23.4dBm,and peak power added efficiency of 16% are achieved from the power amplifier. The MMIC exhibits very low distortion with 3rd order intermodulation (IM) suppression C/I of -13dBc at an output power of 21.2dBm and over 20dBm 3rd order output intercept point (OIP3).

  16. High Power (35 kW and 190 kW) 352 Solid State Amplifiers for the SOLEIL Synchrotron

    CERN Document Server

    Marchand, Patrick; Lopes, Robert; Polian, Jean; Ribeiro, Fernand; Ruan, Ti

    2005-01-01

    In the SOLEIL Storage Ring, two cryomodules, each containing a pair of superconducting cavities will provide the maximum power of 600 kW, required at the nominal energy of 2.75 GeV with the full beam current of 500 mA and all the insertion devices. Each of the four cavities will be powered with a 190 kW solid state amplifier consisting in a combination of 315 W elementary modules (about 750 modules per amplifier). The amplifier modules, based on a technology developed in house, with MOSFET transistor, integrated circulator and individual power supply, are fabricated in the industry. In the booster, a 35 kW solid state amplifier (147 modules) will power a 5-cell copper cavity of the LEP type. The first operational results and the status of the RF power plants are reported in this paper. Although quite innovative for the required power range, the solid state technology proved to be very attractive with significant advantages as compared to vacuum tubes.

  17. A high-linearity SiGe RF power amplifier for 3G and 4G small basestations

    OpenAIRE

    Johansson, Ted; Solati, Noora; Fritzin, Jonas

    2012-01-01

    This article presents the design and evaluation of a linear 3.3V SiGe power amplifier for 3G and 4G femtocells with 18dBm modulated output power at 2140 MHz. Different biasing schemes to achieve high linearity with low standby current were studied. The adjacent channel power ratio linearity performance with wide-band code division multiple access (3G) and long term evolution (4G) downlink signals were compared and differences analysed and explained.

  18. Challenges and Techniques in Measurements of Noise, Cryogenic Noise and Power in Millimeter-Wave and Submillimeter-Wave Amplifiers

    Science.gov (United States)

    Samoska, Lorene

    2014-01-01

    We will present the topic of noise measurements, including cryogenic noise measurements, of Monolithic Microwave Integrated Circuit (MMIC) and Sub-Millimeter-Wave Monolithic Microwave Integrated Circuit (S-MMIC) amplifiers, both on-wafer, and interfaced to waveguide modules via coupling probes. We will also present an overview of the state-of-the-art in waveguide probe techniques for packaging amplifier chips, and discuss methods to obtain the lowest loss packaging techniques available to date. Linearity in noise measurements will be discussed, and experimental methods for room temperature and cryogenic noise measurements will be presented. We will also present a discussion of power amplifier measurements for millimeter-wave and submillimeter-wave amplifiers, and the tools and hardware needed for this characterization.

  19. Theoretical analysis and an improvement method of the bias effect on the linearity of RF linear power amplifiers

    Institute of Scientific and Technical Information of China (English)

    Wu Tuo; Chen Hongyi; Qian Dahong

    2009-01-01

    Based on the Gummel-Poon model of BJT, the change of the DC bias as a function of the AC input signal in RF linear power amplifiers is theoretically derived, so that the linearity of different DC bias circuits can be interpreted and compared. According to the analysis results, a quantitative adaptive DC bias circuit is proposed,which can improve the linearity and efficiency. From the simulation and test results, we draw conclusions on how to improve the design of linear power amplifier.

  20. A compact broadband high efficient X-band 9-watt PHEMT MMIC high-power amplifier for phased array radar applications

    NARCIS (Netherlands)

    Hek, A.P. de; Hunneman, P.A.H.; Demmler, M.; Hulsmann, A.

    1999-01-01

    ln this paper the development and measurement results of a compact broadband 9-Watt high efficient X-band high-power amplifier are discussed. The described amplifier has the following state-of-the art performance: an average ouput power of 9 Watt, a gain of 20 dB and an average Power Added Efficienc

  1. High-Efficiency, High-Power Ka-Band Elliptic-Beam Traveling-Wave-Tube Amplifier for Long-Range Space RF Telecommunications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Space telecommunications require amplifiers that are efficient, high-power, wideband, small, lightweight, and highly reliable. Currently, helix traveling wave tube...

  2. Modeling and Predistortion of Envelope Tracking Power Amplifiers using a Memory Binomial Model

    DEFF Research Database (Denmark)

    Tafuri, Felice Francesco; Sira, Daniel; Larsen, Torben

    2013-01-01

    Nowadays envelope tracking (ET) is considered one of the most appealing techniques for the efficiency enhancement of RF power amplifiers (PAs), but it also introduces a number of additional challenges for the system simulation and implementation. In this context, this paper aims to provide a new....... The model definition is based on binomial series, hence the name of memory binomial model (MBM). The MBM is here applied to measured data-sets acquired from an ET measurement set-up. When used as a PA model the MBM showed an NMSE (Normalized Mean Squared Error) as low as −40dB and an ACEPR (Adjacent Channel...... Error Power Ratio) below −51 dB. The simulated predistortion results showed that the MBM can improve the compensation of distortion in the adjacent channel of 5.8 dB and 5.7 dB compared to a memory polynomial predistorter (MPPD). The predistortion performance in the time domain showed an NMSE...

  3. Power amplifier linearization technique with IQ imbalance and crosstalk compensation for broadband MIMO-OFDM transmitters

    Science.gov (United States)

    Gregorio, Fernando; Cousseau, Juan; Werner, Stefan; Riihonen, Taneli; Wichman, Risto

    2011-12-01

    The design of predistortion techniques for broadband multiple input multiple output-OFDM (MIMO-OFDM) systems raises several implementation challenges. First, the large bandwidth of the OFDM signal requires the introduction of memory effects in the PD model. In addition, it is usual to consider an imbalanced in-phase and quadrature (IQ) modulator to translate the predistorted baseband signal to RF. Furthermore, the coupling effects, which occur when the MIMO paths are implemented in the same reduced size chipset, cannot be avoided in MIMO transceivers structures. This study proposes a MIMO-PD system that linearizes the power amplifier response and compensates nonlinear crosstalk and IQ imbalance effects for each branch of the multiantenna system. Efficient recursive algorithms are presented to estimate the complete MIMO-PD coefficients. The algorithms avoid the high computational complexity in previous solutions based on least squares estimation. The performance of the proposed MIMO-PD structure is validated by simulations using a two-transmitter antenna MIMO system. Error vector magnitude and adjacent channel power ratio are evaluated showing significant improvement compared with conventional MIMO-PD systems.

  4. 5.2 GHz variable-gain amplifier and power amplifier driver for WLAN IEEE 802.11a transmitter front-end

    Institute of Scientific and Technical Information of China (English)

    Zhang Xuelian; Yan Jun; Shi Yin; Dai Fa Foster

    2009-01-01

    A 5.2 GHz variable-gain amplifier (VGA) and a power amplifier (PA) driver are designed for WLAN IEEE 802.11a monolithic RFIC. The VGA and the PA driver are implemented in a 50 GHz 0.35 μm SiGe BiCMOS technology and occupy 1.12×1.25 mm2 die area. The VGA with effective temperature compensation is controlled by 5 bits and has a gain range of 34 dB. The PA driver with tuned loads utilizes a differential input, single-ended output topology, and the tuned loads resonate at 5.2 GHz. The maximum overall gain of the VGA and the PA driver is 29 dB with the output third-order intercept point (OIP3) of 11 dBm. The gain drift over the temperature varying from -30 to 85℃ converges within±3 dB. The total current consumption is 45 mA under a 2.85 V power supply.

  5. Microwave phase shifter with controllable power response based on slow-and fast-light effects in semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Xue, Weiqi; Sales, Salvador; Capmany, Jose;

    2009-01-01

    We suggest and experimentally demonstrate a method for increasing the tunable rf phase shift of semiconductor waveguides while at the same time enabling control of the rf power. This method is based on the use of slow- and fast-light effects in a cascade of semiconductor optical amplifiers combined...... with the use of spectral filtering to enhance the role of refractive index dynamics. A continuously tunable phase shift of 240° at a microwave frequency of 19 GHz is demonstrated in a cascade of two semiconductor optical amplifiers, while maintaining an rf power change of less than 1.6 dB. The technique...... is scalable to more amplifiers and should allow realization of an rf phase shift of 360°....

  6. Compact and high-power broadband terahertz source based on femtosecond photonic crystal fiber amplifier

    Institute of Scientific and Technical Information of China (English)

    Feng Liu; Lu Chai; Qirong Xing; Chingyue Wang; Weili Zhang; Xiaokun Hu; Jiang Li; Changlei Wang; Yi Li; Yanfeng Li; YoujianSong; Bowen Liu; Minglie Hu

    2011-01-01

    Terahertz (THz) waves,generally defined in the 0.1-10 THz range are finding growing applications in various important fields[1-4] such as imaging,food and pharmaceutical quality coutrol,security screening,and standoff detection of bio-threat species,among which THz timedomain spectroscopy (THz-TDS)[5] is particularly appealing.However,the low conversion efficiency and low power of typical broadband THz sources severely hinder the utility and realization of the full potential of THzTDS.Recently,there have been efforts to generate THz pulses using compact pump sources in fiber format[6,7].%We present a review of the development of a compact and high-power broadband terahertz (THz) source optically excited by a femtosecond photonic crystal fiber (PCF) amplifier. The large mode area of the PCF and the stretcher-free configuration make the pump source compact and very efficient. Broadband THz pulseg of 150 μW extending from 0.1 to 3.5 TH2 are generated from a 3-mm-thick GaP crystal through optical rectification of 12-W pump pulses with duration of 66 & and a repetition rate of 52 MHz. A strong saturation effect is observed, which is attributed to pump pulse absorption; a Z-scan measurement shows that three-photon absorption dominates the nonlinear absorption when the crystal is pumped by femtosecond pulses at 1040 run. A further scale-up of the THz source power is expected to find important applications in THz nonlinear optics and nonlinear THz spectroscope

  7. RF power upgrade at the superconducting 1.3 GHz CW LINAC “ELBE” with solid state amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Büttig, Hartmut, E-mail: buettig@hzdr.de [Radiation Source ELBE, Helmholtz Zentrum Dresden-Rossendorf (Germany); Arnold, A.; Büchner, A.; Justus, M.; Kuntsch, M.; Lehnert, U.; Michel, P.; Schurig, R.; Staats, G.; Teichert, J. [Radiation Source ELBE, Helmholtz Zentrum Dresden-Rossendorf (Germany)

    2013-03-11

    The RF power for the superconducting 1.3 GHz CW LINAC “ELBE” has been doubled from less than 10 kW to 20 kW per cavity. In January 2012 the four 10 kW klystrons used to drive the four superconducting cavities of the LINAC have been replaced by pairs of 10 kW solid state power amplifiers (SSPA). ELBE is now worldwide the first 1.3 GHz CW LINAC equipped with solid state RF power amplifiers. This technical note details on this project. -- Highlights: ► We report the first installation of 10 kW solid state RF-amplifiers at 1.3 GHz CW LINAC. ► The sc. cavities of “ELBE” are now driven by a pair of 10 kW solid state amplifiers (SSPA). ► The RF-power upgrade allows doubling the electron beam current (CW). ► Advantages of the new RF system are high reliability, easy service and lower costs.

  8. Ka-Band Wide-Bandgap Solid-State Power Amplifier: Prototype Combiner Spurious Mode Suppression and Power Constraints

    Science.gov (United States)

    Khan, P.; Epp, L.

    2006-01-01

    Results of prototype hardware activities related to a 120-W, 32-GHz (Ka-band) solid-state power amplifier (SSPA) architecture study are presented. Spurious mode suppression and the power-handling capability of a prototype 24-way radial combiner and a prototype 2-way septum binary combiner were investigated. Experimental data indicate that a commercial absorptive filter, designed to pass the circular TE01 mode, effectively suppressed the higher-order modes generated by a narrowband, flower-petal-type mode transducer. However, the same filter was not effective in suppressing higher-order modes generated by the broadband Marie mode transducer that is used in the prototype waveguide radial combiner. Should greater filtering be required by a particular SSPA application, a broadband mode filter that can suppress specifically those higher-order modes that are generated by the Marie transducer will need to be developed. A back-to-back configuration of the prototype radial combiner was tested with drive power up to approximately 50 W. No anomalous behavior was observed. Power measurements of the septum combiner indicate that up to 10-W radio frequency (RF) can be dissipated in the integrated resistive element before a permanent performance shift is observed. Thus, a given adder (a single-stage, 2-way combiner) can safely combine two 20-W sources, and the adder will not be damaged in the event of a source failure. This result is used to calculate the maximum source power that can be safely combined as a function of the number of sources combined and the number of source failures allowed in a multi-stage combiner. The analysis shows that SSPA power >140 W can be generated by power combining 16 sources producing 10 W each. In this configuration, up to three sources could fail with the guarantee that the combiner would not be damaged. Finally, a modified prototype septum combiner design was verified. The improved design reduced the assembly time from over 2 hours to about 15

  9. Efficiency Enhancement of Pico-cell Base Station Power Amplifier MMIC in Gallium Nitride HFET Technology Using the Doherty technique

    Science.gov (United States)

    Seneviratne, Sashieka

    With the growth of smart phones, the demand for more broadband, data centric technologies are being driven higher. As mobile operators worldwide plan and deploy 4th generation (4G) networks such as LTE to support the relentless growth in mobile data demand, the need for strategically positioned pico-sized cellular base stations known as 'pico-cells' are gaining traction. In addition to having to design a transceiver in a much compact footprint, pico-cells must still face the technical challenges presented by the new 4G systems, such as reduced power consumptions and linear amplification of the signals. The RF power amplifier (PA) that amplifies the output signals of 4G pico-cell systems face challenges to minimize size, achieve high average efficiencies and broader bandwidths while maintaining linearity and operating at higher frequencies. 4G standards as LTE use non-constant envelope modulation techniques with high peak to average ratios. Power amplifiers implemented in such applications are forced to operate at a backed off region from saturation. Therefore, in order to reduce power consumption, a design of a high efficiency PA that can maintain the efficiency for a wider range of radio frequency signals is required. The primary focus of this thesis is to enhance the efficiency of a compact RF amplifier suitable for a 4G pico-cell base station. For this aim, an integrated two way Doherty amplifier design in a compact 10mm x 11.5mm2 monolithic microwave integrated circuit using GaN device technology is presented. Using non-linear GaN HFETs models, the design achieves high effi-ciencies of over 50% at both back-off and peak power regions without compromising on the stringent linearity requirements of 4G LTE standards. This demonstrates a 17% increase in power added efficiency at 6 dB back off from peak power compared to conventional Class AB amplifier performance. Performance optimization techniques to select between high efficiency and high linearity operation are

  10. A Compact Two-Stage 120 W GaN High Power Amplifier for SweepSAR Radar Systems

    Science.gov (United States)

    Thrivikraman, Tushar; Horst, Stephen; Price, Douglas; Hoffman, James; Veilleux, Louise

    2014-01-01

    This work presents the design and measured results of a fully integrated switched power two-stage GaN HEMT high-power amplifier (HPA) achieving 60% power-added efficiency at over 120Woutput power. This high-efficiency GaN HEMT HPA is an enabling technology for L-band SweepSAR interferometric instruments that enable frequent repeat intervals and high-resolution imagery. The L-band HPA was designed using space-qualified state-of-the-art GaN HEMT technology. The amplifier exhibits over 34 dB of power gain at 51 dBm of output power across an 80 MHz bandwidth. The HPA is divided into two stages, an 8 W driver stage and 120 W output stage. The amplifier is designed for pulsed operation, with a high-speed DC drain switch operating at the pulsed-repetition interval and settles within 200 ns. In addition to the electrical design, a thermally optimized package was designed, that allows for direct thermal radiation to maintain low-junction temperatures for the GaN parts maximizing long-term reliability. Lastly, real radar waveforms are characterized and analysis of amplitude and phase stability over temperature demonstrate ultra-stable operation over temperature using integrated bias compensation circuitry allowing less than 0.2 dB amplitude variation and 2 deg phase variation over a 70 C range.

  11. A novel matching network employing surface acoustic wave devices for W-CDMA power amplifiers.

    Science.gov (United States)

    Li, Honglang; He, Songbai; Hashimoto, Ken-ya; Omori, Tatsuya; Yamaguchi, Masatsune

    2006-12-22

    This paper describes a new approach of designing high Q surface acoustic wave (SAW) resonators as an inductive element in the matching network for W-CDMA power amplifiers (PAs). Spiral inductors based on CMOS/BiCMOS technologies presently possess relatively low Q (typically <10) and occupy a considerably large area. In order to break through the limitations of the spiral inductors, the authors attempt to apply higher Q and wideband SAW resonators employing Cu-grating/15 degrees YX-LiNbO(3)-substrate structure to the matching network for improved PA performance. An analysis was made on SAW resonators in detail, and an SAW resonator having a very small capacitance ratio of 3.28 and moderate Q of 147.8 was developed. After discussing the frequency dependence of the effective inductances, SAW resonators, which are used to be as inductive elements in the matching networks of PAs, were designed and fabricated. The PA including the matching circuit was simulated using the characteristics of the fabricated SAW resonators. The result showed that with better shape factor and good out-of-rejection, the SAW resonators definitely work as an inductive element and could replace widely used spiral inductors.

  12. Optimal Configuration of Multiple Pump Powers and Wavelengths for Balanced Pre- and Post-pumped Raman Fiber Amplifiers

    Institute of Scientific and Technical Information of China (English)

    YAN Minhui; CHEN Jianping; LI Jianlang; JIANG Wenning; CHEN Junfeng; LI Xin

    2002-01-01

    A novel configuration algorithm for bi-directionally pumped Raman amplifier is developed by adopting simulated annealing algorithm. Automatic design of optical fiber Raman amplifier using 10 laser diode pumps with different wavelengths and powers is demonstrated for 64 channels DWDM systems. The resulted gain ripple is less than 2.6 dB in amplification bandwidth of more than 50 nm for a transmission span of more than 300 km. The algorithm can be practically applied to desired signal channel number and gain profile.

  13. Damage behavior of Nd:glass of high-power disk amplifier medium in ICF Facility

    Science.gov (United States)

    He, Shaobo; Chen, Lin; Yuan, Xiaodong; Chen, Yuanbin; Cheng, Xiaofeng; Xie, Xudong; Wang, Wenyi; Zu, Xiaotao

    2016-12-01

    Large aperture Nd:glass disk is often used as the amplifier medium in the inertial confinement fusion (ICF) facilities. The typical size of Nd:glass is up to 810mm×460mm×40mm and more than 3,000 Nd:glass components are needed in the ICF facility. At present, the 3ω fused silica glass and DKDP crystal are mainly responsible for the damage of driver used for ICF. However, with the enlargement of the facility and increase of laser shot number, the laser damage of Nd:glass at 1ω waveband is still an important problem to limit the stable operation of facility and improvement of laser beam quality. In this work, the influence of Nd:glass material itself, mechanical processing, service environment, and laser beam quality on its damage behavior is investigated experimentally and theoretically. The results and conclusions can be summarized as follows: (1) It is very important to control the concentration of platinum impurity particles during melting and the sputtering effect of the cladding materials. (2) The number and length of fractural and brittle scratches should be strictly suppressed during mechanical processing of Nd:glass. (3) The B-integral of high power laser beam should be rigorously controlled. Particularly, the top shape of pulses must be well controlled when operating at high peak laser power. (4) The service environment should be well managed to make sure the cleanness of the surface of Nd:glass better than 100/A level during mounting and running. (5) The service environment and beam quality should be monitored during operation.

  14. Intelligent audio analysis

    CERN Document Server

    Schuller, Björn W

    2013-01-01

    This book provides the reader with the knowledge necessary for comprehension of the field of Intelligent Audio Analysis. It firstly introduces standard methods and discusses the typical Intelligent Audio Analysis chain going from audio data to audio features to audio recognition.  Further, an introduction to audio source separation, and enhancement and robustness are given. After the introductory parts, the book shows several applications for the three types of audio: speech, music, and general sound. Each task is shortly introduced, followed by a description of the specific data and methods applied, experiments and results, and a conclusion for this specific task. The books provides benchmark results and standardized test-beds for a broader range of audio analysis tasks. The main focus thereby lies on the parallel advancement of realism in audio analysis, as too often today’s results are overly optimistic owing to idealized testing conditions, and it serves to stimulate synergies arising from transfer of ...

  15. Full characterization of the amplified spontaneous emission from a diode-pumped high-power laser system.

    Science.gov (United States)

    Keppler, S; Hornung, M; Bödefeld, R; Sävert, A; Liebetrau, H; Hein, J; Kaluza, M C

    2014-05-01

    We present the first complete temporal and spatial characterization of the amplified spontaneous emission (ASE) of laser radiation generated by a diode-pumped high-power laser system. The ASE of the different amplifiers was measured independently from the main pulse and was characterized within a time window of -10ms ≤ t ≤ 10ms and an accuracy of up to 15fs around the main pulse. Furthermore, the focusability and the energy of the ASE from each amplifier was measured after recompression. Using our analysis method, the laser components, which need to be optimized for a further improvement of the laser contrast, can be identified. This will be essential for laser-matter interaction experiments requiring a minimized ASE intensity or fluence.

  16. An RF power amplifier with inter-metal-shuffled capacitor for inter-stage matching in a digital CMOS process

    Institute of Scientific and Technical Information of China (English)

    Feng Xiaoxing; Zhang Xing; Ge Binjie; Wang Xin'an

    2009-01-01

    One challenge of the implementation of fully-integrated RF power amplifiers into a deep submicro digital CMOS process is that no capacitor is available, especially no high density capacitor. To address this problem, a twostage class-AB power amplifier with inter-stage matching realized by an inter-metal coupling capacitor is designed in a 180-nm digital CMOS process. This paper compares three structures of inter-metal coupling capacitors with metal-insulator-metal (MIM) capacitor regarding their capacitor density. Detailed simulations are carried out for the leakage, the voltage dependency, the temperature dependency, and the quality factor between an inter-metal shuffled (IMS) capacitor and an MIM capacitor. Finally, an IMS capacitor is chosen to perform the inter-stage matching.The techniques are validated via the design and implement of a two-stage class-AB RF power amplifier for an UHF RFID application. The PA occupies 370 X 200 μm2 without pads in the 180-nm digital CMOS process and outputs 21.1 dBm with 40% drain efficiency and 28.1 dB power gain at 915 MHz from a single 3.3 V power supply.

  17. Energy-Efficient Power Allocation for Fixed-Gain Amplify-and-Forward Relay Networks with Partial Channel State Information

    KAUST Repository

    Zafar, Ammar

    2012-06-01

    In this report, energy-efficient transmission and power allocation for fixed-gain amplify-and-forward relay networks with partial channel state information (CSI) are studied. In the energy-efficiency problem, the total power consumed is minimized while keeping the signal-to-noise-ratio (SNR) above a certain threshold. In the dual problem of power allocation, the end-to-end SNR is maximized under individual and global power constraints. Closed-form expressions for the optimal source and relay powers and the Lagrangian multiplier are obtained. Numerical results show that the optimal power allocation with partial CSI provides comparable performance as optimal power allocation with full CSI at low SNR.

  18. Energy-Efficient Power Allocation for Fixed-Gain Amplify-and-Forward Relay Networks with Partial Channel State Information

    KAUST Repository

    Zafar, Ammar

    2012-09-16

    In this letter, energy-efficient transmission and power allocation for fixed-gain amplify-and-forward relay networks with partial channel state information (CSI) are studied. In the energy-efficiency problem, the total power consumed is minimized while keeping the signal-to-noise-ratio (SNR) above a certain threshold. In the dual problem of power allocation, the end-to-end SNR is maximized under individual and global power constraints. Closed-form expressions for the optimal source and relay powers and the Lagrangian multiplier are obtained. Numerical results show that the optimal power allocation with partial CSI provides comparable performance as optimal power allocation with full CSI at low SNR. © 2012 IEEE.

  19. Authentication of digital audio recording based on power system frequency%基于电网频率的数字录音真伪鉴别研究

    Institute of Scientific and Technical Information of China (English)

    刘育明; 姚陈果; 孙才新; 袁智勇; Liu Yilu

    2013-01-01

    采用电网频率鉴别数字录音真伪是司法科学领域近年来的研究热点.在北美电网频率监测系统(FNET)的基础上,构建用于数字录音信号真伪鉴别的专用标准电网频率数据库,提出一种完整的真伪鉴别算法.采用数字滤波技术和短时傅里叶变换估计蕴含在数字信号中的电网频率分量,通过补零操作及三点样条插值提高频率估计的准确度;首次考虑数字采集系统振荡器对频率数据库匹配的影响,提出一种迭代式振荡器误差校正方法;分析短时傅里叶变换的参数选择,如窗函数、补零系数对频率估计准确度的影响,最后实现了该套数字录音真伪鉴别算法.在实测数字语音信号上的实验结果表明,该方法能有效地鉴别数字信号的真伪并确定其原创时间.%Power system frequency has recently been explored for digital audio authentication in the field of forensic science.This paper firstly establishes an ad hoc power system frequency reference database according to the North American frequency monitoring system (FNET),and then proposes a thorough algorithm for the authentication problem.Digital filtering is incorporated with short-time Fourier transform (STFT) to estimate the coarse frequency embedded in a questioned digital audio recording,then zero-padding operation and three-point spline interpolation are adopted to improve the accuracy of frequency estimation.An iterative method for oscillator error correction is put forward for the first time considering the effect of digital acquisition system oscillator on frequency database matching.Moreover,the selection of the STFT parameters,such as window functions and zero-padding coefficient,are also discussed.Finally,the digital audio recording authentication algorithm is implemented;the experiment result for real tested digital audio recording signal indicates that the proposed algorithm can effectively realize digital audio recording signal

  20. Decomposition of piecewise-polynomial model of a predistorter for power amplifier

    OpenAIRE

    2015-01-01

    Decomposition of piecewise-polynomial model of a predistorter has been performed taking into account the alteration dynamics of the complex envelope’s magnitude for the signal, which is converted by an amplifier. Decomposition model provides higher accuracy of nonlinear distortions compensation for signals in the amplifier compared with piecewise-polynomial model of a predistorter. Comparative analysis of predistorters’ models has been carried out for the linearization of the Wiener–Hammerste...

  1. Audio Indexing for Efficiency

    Science.gov (United States)

    Rahnlom, Harold F.; Pedrick, Lillian

    1978-01-01

    This article describes Zimdex, an audio indexing system developed to solve the problem of indexing audio materials for individual instruction in the content area of the mathematics of life insurance. (Author)

  2. Newnes audio and Hi-Fi engineer's pocket book

    CERN Document Server

    Capel, Vivian

    2013-01-01

    Newnes Audio and Hi-Fi Engineer's Pocket Book, Second Edition provides concise discussion of several audio topics. The book is comprised of 10 chapters that cover different audio equipment. The coverage of the text includes microphones, gramophones, compact discs, and tape recorders. The book also covers high-quality radio, amplifiers, and loudspeakers. The book then reviews the concepts of sound and acoustics, and presents some facts and formulas relevant to audio. The text will be useful to sound engineers and other professionals whose work involves sound systems.

  3. High power resonant pumping of Tm-doped fiber amplifiers in core- and cladding-pumped configurations.

    Science.gov (United States)

    Creeden, Daniel; Johnson, Benjamin R; Rines, Glen A; Setzler, Scott D

    2014-11-17

    We have demonstrated ultra-high efficiency amplification in Tm-doped fiber with both core- and cladding-pumped configurations using a resonant tandem-pumping approach. These Tm-doped fiber amplifiers are pumped in-band with a 1908 nm Tm-doped fiber laser and operate at 1993 nm with >90% slope efficiency. In a core-pumped configuration, we have achieved 92.1% slope efficiency and 88.4% optical efficiency at 41 W output power. In a cladding-pumped configuration, we have achieved 123.1 W of output power with 90.4% optical efficiency and a 91.6% slope efficiency. We believe these are the highest optical efficiencies achieved in a Tm-doped fiber amplifier operating in the 2-micron spectral region.

  4. BER and optimal power allocation for amplify-and-forward relaying using pilot-aided maximum likelihood estimation

    KAUST Repository

    Wang, Kezhi

    2014-10-01

    Bit error rate (BER) and outage probability for amplify-and-forward (AF) relaying systems with two different channel estimation methods, disintegrated channel estimation and cascaded channel estimation, using pilot-aided maximum likelihood method in slowly fading Rayleigh channels are derived. Based on the BERs, the optimal values of pilot power under the total transmitting power constraints at the source and the optimal values of pilot power under the total transmitting power constraints at the relay are obtained, separately. Moreover, the optimal power allocation between the pilot power at the source, the pilot power at the relay, the data power at the source and the data power at the relay are obtained when their total transmitting power is fixed. Numerical results show that the derived BER expressions match with the simulation results. They also show that the proposed systems with optimal power allocation outperform the conventional systems without power allocation under the same other conditions. In some cases, the gain could be as large as several dB\\'s in effective signal-to-noise ratio.

  5. A 1.2 V low-power OpAmp for integrated lock-in amplifiers

    Science.gov (United States)

    Valero, M. R.; Celma, S.; Medrano, N.; Calvo, B.; Gimeno, C.

    2013-05-01

    This paper presents a simple 1.2 V low-power rail-to-rail class AB operational amplifier (OpAmp) suitable for integrated lock-in amplifiers. The proposed OpAmp has been designed in a standard 0.18 μm CMOS technology. For a 1.2 V single supply and 68.6 μW power consumption, simulations shows a 81 dB open loop gain, 64° phase margin, 13 MHz unity gain frequency for a capacitive load of 10pF and 75 dB CMRR. Adaptive biasing provides 30.7 V/μs slew-rate for a 10 pF load. A compact and reliable lock-in amplifier (LIA) has been designed using the proposed circuit. The designed LIA has a power consumption of 135 μW and recovers signals up to 1 MHz with relative errors below 2.6 % for noise and interference signals of the same amplitude as the signal of interest.

  6. Ultra High Power and Efficiency Space Traveling-Wave Tube Amplifier Power Combiner with Reduced Size and Mass for NASA Missions

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.; Wilson, Jeffrey D.; Force, Dale A.

    2009-01-01

    In the 2008 International Microwave Symposium (IMS) Digest version of our paper, recent advances in high power and efficiency space traveling-wave tube amplifiers (TWTAs) for NASA s space-to-Earth communications are presented. The RF power and efficiency of a new K-Band amplifier are 40 W and 50 percent and that of a new Ka-Band amplifier are 200 W and 60 percent. An important figure-of-merit, which is defined as the ratio of the RF power output to the mass (W/kg) of a TWT, has improved by a factor of ten over the previous generation Ka-Band devices. In this extended paper, a high power, high efficiency Ka-band combiner for multiple TWTs, based on a novel hybrid magic-T waveguide circuit design, is presented. The measured combiner efficiency is as high as 90 percent. In addition, at the design frequency of 32.05 GHz, error-free uncoded BPSK/QPSK data transmission at 8 megabits per second (Mbps), which is typical for deep space communications is demonstrated. Furthermore, QPSK data transmission at 622 Mbps is demonstrated with a low bit error rate of 2.4x10(exp -8), which exceeds the deep space state-of-the-art data rate transmission capability by more than two orders of magnitude. A potential application of the TWT combiner is in deep space communication systems for planetary exploration requiring transmitter power on the order of a kilowatt or higher.

  7. Back to basics audio

    CERN Document Server

    Nathan, Julian

    1998-01-01

    Back to Basics Audio is a thorough, yet approachable handbook on audio electronics theory and equipment. The first part of the book discusses electrical and audio principles. Those principles form a basis for understanding the operation of equipment and systems, covered in the second section. Finally, the author addresses planning and installation of a home audio system.Julian Nathan joined the audio service and manufacturing industry in 1954 and moved into motion picture engineering and production in 1960. He installed and operated recording theaters in Sydney, Austra

  8. High efficiency 600-mW pHEMT distributed power amplifier employing drain impedance tapering technique

    DEFF Research Database (Denmark)

    Narendra, Kumar; Anand, Lokesh; Pragash, Sangaran;

    2008-01-01

    4-stage distributed power amplifier (DPA) employing tapering the drain load networks to achieve high efficiency is reported. The active device with enhancement mode pHEMT (pseudomorphic High Electron Mobility Transistor) technology is used. Measurement results of 600 mW, 30 % of power-aided-effic......-aided-efficiency (PAE) and gain of 10 dB is achieved within frequency range of 10–1800 MHz. Low supply voltage of 4.5 V is used for each device. Good agreement between measured and simulated results is obtained....

  9. Low-Power Three-Stage Amplifier Using Active-Feedback Miller Capacitor and Serial RC Frequency Compensation

    Institute of Scientific and Technical Information of China (English)

    张庚宇; 肖夏; 聂凯明; 徐江涛

    2015-01-01

    A low-power three-stage amplifier for driving large capacitive load is proposed. The feedback path formed by the active-feedback Miller capacitor leads to a high frequency complex-pole but a highQ-value, which significantly deteriorates the stability of the amplifier. The serial RC stage introduced as the second stage output load can optimize the resistorRz and the capacitorCz under fixed power and small compensation capacitorCa, which brings about a suitableQ-value of the complex-pole and the gain-bandwidth product extension of the ampli-fier. The amplifiers were designed and implemented in a standard 65 nm CMOS process with capacitive loads of 500 pF and 2 nF, respectively. The post-layout simulation results show that the amplifier driving the 500 pF capaci-tive load can achieve a gain of 113 dB, a phase margin of 50.6° and a gain-bandwidth product of 5.22 MHz while consuming 24 µW from a 1.2 V supply. For the 2 nF capacitive load, the amplifier has a gain of 102 dB, a phase margin of 52.8°, a gain-bandwidth product of 4.41 MHz and a power of 43 µW. The total compensation capacitors are equal to 1.13 pF and 1.03 pF. The better figures-of-merits are 108 750 and 205 113(MHz×pF/mW). The lay-out areas are 0.064 mm×0.026 mm and 0.063 mm×0.027 mm. Compared with the CFCC scheme, the gain-bandwidth product is extended by 1.6 times atCL=500 pF andCa=1.1 pF.

  10. High power 888 nm optical fiber end-pumped Nd:YVO4 picosecond regenerative amplifier at hundreds kHz

    Science.gov (United States)

    Bai, Zhenao; Fan, Zhongwei; Lian, Fuqiang; Tan, Tan; Bai, Zhenxu; Yang, Chao; Kang, Zhijun; Liu, Chang

    2016-10-01

    This paper describes a demonstration of a high power 888 nm end-pumped Nd:YVO4 picosecond regenerative amplifier operated at high repetition rate. By utilizing an all-fiber mode-locking picosecond laser as seed source and 888 nm continuous wave (CW) as pumping source, we obtained regenerative amplified output at 1064.07 nm with spectrum width 0.16 nm, pulse width of 38 ps, maximum power of 21 W, and the repetition rate is continuously adjustable from 300 to 500 kHz. The regenerative amplifier has high power stability and high compact structure.

  11. 500 MW peak power degenerated optical parametric amplifier delivering 52 fs pulses at 97 kHz repetition rate.

    Science.gov (United States)

    Rothhardt, J; Hädrich, S; Röser, F; Limpert, J; Tünnermann, A

    2008-06-09

    We present a high peak power degenerated parametric amplifier operating at 1030 nm and 97 kHz repetition rate. Pulses of a state-of-the art fiber chirped-pulse amplification (FCPA) system with 840 fs pulse duration and 410 microJ pulse energy are used as pump and seed source for a two stage optical parametric amplifier. Additional spectral broadening of the seed signal in a photonic crystal fiber creates enough bandwidth for ultrashort pulse generation. Subsequent amplification of the broadband seed signal in two 1 mm BBO crystals results in 41 microJ output pulse energy. Compression in a SF 11 prism compressor yields 37 microJ pulses as short as 52 fs. Thus, pulse shortening of more than one order of magnitude is achieved. Further scaling in terms of average power and pulse energy seems possible and will be discussed, since both concepts involved, the fiber laser and the parametric amplifier have the reputation to be immune against thermo-optical effects.

  12. UHF power amplifier design in 0.35μm SiGe BiCMOS

    Institute of Scientific and Technical Information of China (English)

    Song Jiayou; Li Zhiqun; Wang Zhigon

    2009-01-01

    A two-stage power amplifier operated at 925 MHz was designed and fabricated in Jazz's 0.35μm SiGe BiCMOS process. It was fully integrated excluding the inductors and the output matching network. Under a single 3.3V supply voltage, the off-chip bonding test results indicated that the circuit has a small signal gain of more than 24dB, the input and output reflectance are less than -24dB and -10dB, respectively, and the maximal output power is 23.5 dBm. At output power of 23.1 dBm, the PAE (power added efficiency) is 30.2%, the IMD2 and IMD3 are less than -32 dBc and -46 dBc, respectively. The chip size is 1.27mm×0.9mm.

  13. Design and analysis of an integrated pulse modulated s-band power amplifier in gallium nitride process

    Energy Technology Data Exchange (ETDEWEB)

    Sedlock, Steve [Kansas State Univ., Manhattan, KS (United States)

    2012-01-01

    The design of power amplifiers in any semi-conductor process is not a trivia exercise and it is often encountered that the simulated solution is qualitatively different than the results obtained. Phenomena such as oscillation occurring either in-band or out of band and sometimes at subharmonic intervals, continuous spectrum noticed in some frequency bands, often referred to as chaos, and jumps and hysteresis effects can all be encountered and render a design useless. All of these problems might have been identified through a more rigorous approach to stability analysis. Designing for stability is probably the one area of amplifier design that receives the least amount of attention but incurs the most catastrophic of effects if it is not performed properly. Other parameters such as gain, power output, frequency response and even matching may suitable mitigation paths. But the lack of stability in an amplifier has no mitigating path. In addition to of loss of the design completely there are the increased production cycle costs, costs involved with investigating and resolving the problem and the costs involved with schedule slips or delays resulting from it. The Linville or Rollett stability criteria that many microwave engineers follow and rely exclusively on is not sufficient by itself to ensure a stable and robust design. It will be shown that the universal belief that unconditional stability is obtained through an analysis of the scattering matrix S to determine if 1 and |{Delta}{sub S}| < 1 is only part of the procedure and other tools must be used to validate the criteria. The research shown contributes to the state of the art by developing a more thorough stability design technique for designing amplifiers of any class, whether that be current mode or switch mode, than is currently undertaken with the goal of obtaining first pass design success.

  14. Characterization of a High-SpeedHigh-Power Semiconductor Master-Oscillator Power-Amplifier (MOPA) Laser as a Free-Space Transmitter

    Science.gov (United States)

    Wright, M. W.

    2000-04-01

    Semiconductor lasers offer promise as high-speed transmitters for free-space optical communication systems. This article examines the performance of a semiconductor laser system in a master-oscillator power-amplifier (MOPA) geometry developed through a Small Business Innovation Research (SBIR) contract with SDL, Inc. The compact thermo-electric cooler (TEC) packaged device is capable of 1-W output optical power at greater than 2-Gb/s data rates and a wavelength of 960 nm. In particular, we have investigated the effects of amplified spontaneous emission on the modulation extinction ratio and bit-error rate (BER) performance. BERs of up to 10^(-9) were possible at 1.4 Gb/s; however, the modulation extinction ratio was limited to 6 dB. Other key parameters for a free-space optical transmitter, such as the electrical-optical efficiency (24 percent) and beam quality, also were measured.

  15. Cross-differential amplifier

    Science.gov (United States)

    Hajimiri, Seyed-Ali (Inventor); Kee, Scott D. (Inventor); Aoki, Ichiro (Inventor)

    2013-01-01

    A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches.

  16. Femtosecond pulses at 50-W average power from an Yb:YAG planar waveguide amplifier seeded by an Yb:KYW oscillator.

    Science.gov (United States)

    Leburn, Christopher G; Ramírez-Corral, Cristtel Y; Thomson, Ian J; Hall, Denis R; Baker, Howard J; Reid, Derryck T

    2012-07-30

    We report the demonstration of a high-power single-side-pumped Yb:YAG planar waveguide amplifier seeded by an Yb:KYW femtosecond laser. Five passes through the amplifier yielded 700-fs pulses with average powers of 50 W at 1030 nm. A numerical simulation of the amplifier implied values for the laser transition saturation intensity, the small-signal intensity gain coefficient and the gain bandwidth of 10.0 kW cm(-2), 1.6 cm(-1), and 3.7 nm respectively, and identified gain-narrowing as the dominant pulse-shaping mechanism.

  17. Principles of Audio Watermarking

    Directory of Open Access Journals (Sweden)

    Martin Hrncar

    2008-01-01

    Full Text Available The article contains a brief overview of modern methods for embedding additional data in audio signals. It could have many reasons - for the purposes of access control or identification related to particular type of audio. This secret information is not “visible” for a user. This concept utilizes the imperfection of human auditory system. Simple data hiding into audio file has been proved in MATLAB.

  18. Theoretical and numerical treatment of modal instability in high-power core and cladding-pumped Raman fiber amplifiers.

    Science.gov (United States)

    Naderi, Shadi; Dajani, Iyad; Grosek, Jacob; Madden, Timothy

    2016-07-25

    Raman fiber lasers have been proposed as potential candidates for scaling beyond the power limitations imposed on near diffraction-limited rare-earth doped fiber lasers. One limitation is the modal instability (MI) and we explore the physics of this phenomenon in Raman fiber amplifiers (RFAs). By utilizing the conservation of number of photons and conservation of energy in the absence of loss, the 3 × 3 governing system of nonlinear equations describing the pump and the signal modal content are decoupled and solved analytically for cladding-pumped RFAs. By comparing the extracted signal at MI threshold for the same step index-fiber, it is found that the MI threshold is independent of the length of the amplifier or whether the amplifier is co-pumped or counter-pumped; dictated by the integrated heat load along the length of fiber. We extend our treatment to gain-tailored RFAs and show that this approach is of limited utility in suppressing MI. Finally, we formulate the physics of MI in core-pumped RFAs where both pump and signal interferences participate in writing the time-dependent index of refraction grating.

  19. Audio Papers - A Manifesto

    DEFF Research Database (Denmark)

    Krogh Groth, Sanne; Samson, Kristine

    2016-01-01

    Audio papers resemble the regular essay or the academic text in that they deal with a certain topic of interest, but presented in the form of an audio production. The audio paper is an extension of the written paper through its specific use of media, a sonic awareness of aesthetics and materiality......, and creative approach towards communication. The audio paper is a performative format working together with an affective and elaborate understanding of language. It is an experiment embracing intellectual arguments and creative work, papers and performances, written scholarship and sonic aesthetics....

  20. Digital Audio Legal Recorder

    Data.gov (United States)

    Department of Transportation — The Digital Audio Legal Recorder (DALR) provides the legal recording capability between air traffic controllers, pilots and ground-based air traffic control TRACONs...

  1. High-Power Hybrid Mode-Locked External Cavity Semiconductor Laser Using Tapered Amplifier with Large Tunability

    Directory of Open Access Journals (Sweden)

    Andreas Schmitt-Sody

    2008-01-01

    Full Text Available We report on hybrid mode-locked laser operation of a tapered semiconductor amplifier in an external ring cavity, generating pulses as short as 0.5 ps at 88.1 MHz with an average power of 60 mW. The mode locking is achieved through a combination of a multiple quantum well saturable absorber (>10% modulation depth and an RF current modulation. This designed laser has 20 nm tuning bandwidth in continuous wave and 10 nm tuning bandwidth in mode locking around 786 nm center wavelength at constant temperature.

  2. Single-Frequency, Yb-Free, Resonantly Cladding-Pumped Large Mode Area Er Fiber Amplifier for Power Scaling

    Science.gov (United States)

    2008-07-25

    report results for a single-frequency SF resonantly cladding-pumped Yb-free large mode area LMA erbium-doped fiber amplifier EDFA with nearly 50...original demonstration of a SF resonantly cladding-pumped LMA EDFA . We obtained a diffraction-limited SF output of 9.3 W, which is also a record power...output obtained for resonantly cladding-pumped LMA EDFA . © 2008 American Institute of Physics. DOI: 10.1063/1.2964189 Recent advances in eye-safe 1.5

  3. Gain variation induced by power transient in thulium-doped fiber amplifier at 2 μm and its reduction by optical gain clamping technique

    Science.gov (United States)

    Khamis, M. A.; Ennser, K.

    2017-02-01

    This paper investigates the dynamic behavior of a thulium doped fiber amplifier (TDFA) operating in the 2 μm region for reconfigurable wavelength division multiplexing (WDM) systems. We show deleterious channel power fluctuations may be generated by input power variation at the amplifier and we propose the use of an optical gain-clamping technique. The investigated system consists of 20 channels with -4 dBm total input power. Our findings revealed that the effects of power transients due to channel reconfigurations are significantly reduced by a lasing feedback signal. Simulation results show that a power excursion of 4.3 dB is produced after dropping 19 channels when the amplifier gain is unclamped and only 0.0062 dB when the amplifier gain is clamped. The dynamics of GC-TDFA are mainly influenced by the value of the pump power factor and thus the laser signal achieves a stronger stabilization condition with increasing pump power factor. Hence, optical gain clamping is a simple and robust technique to control the power transient in the thulium-doped fiber amplifier of WDM systems at 2 μm.

  4. High-power SiC MESFET using a dual p-buffer layer for an S-band power amplifier

    Institute of Scientific and Technical Information of China (English)

    Deng Xiao-Chuan; Sun He; Rao Cheng-Yuan; Zhang Bo

    2013-01-01

    A silicon carbide (SiC) based metal semiconductor field effect transistor (MESFET) is fabricated by using a standard SiC MESFET structure with the application of a dual p-buffer layer and a multi-recessed gate to the process for an S-band power amplifier.The lower doped upper-buffer layer serves to maintain the channel current,while the higher doped lowerbuffer layer is used to provide excellent electron confinement in the channel layer.A 20-mm gate periphery SiC MESFET biased at a drain voltage of 85 V demonstrates a pulsed wave saturated output power of 94 W,a linear gain of 11.7 dB,and a maximum power added efficiency of 24.3% at 3.4 GHz.These results are improved compared with those of the conventional single p-buffer MESFET fabricated in this work using the same process.A radio-frequency power output greater than 4.7 W/mm is achieved,showing the potential as a high-voltage operation device for high-power solid-state amplifier applications.

  5. Noise Shaping Filter Compensating PWM Distortion for Fully Digital Amplifier

    Science.gov (United States)

    Yoneya, Akihiko

    The full-digital audio amplifiers have several merits such as a high power enabling a small size of the amplifier and digital implementation of the signal processing which allows desired precision of the processing except for the final stage switching amplifiers. Unfortunately, the pulse width modulation (PWM) causes signal distortions because of the non-linearity of the modulation from the viewpoint of the transient response. This paper proposes a compensation method of the PWM distortion with feedback approach. In the noise-shaping filter of the delta-sigma modulator to calculate the pulse codes for the PWM, the distortion caused by the PWM is evaluated and fed it back to compensate the distortion. Eventually the filter is implemented as a state-variable filter with non-linear feedback from the quantizer. The calculation of the filter elements is also described. By using proposed filters, PWM signals with small distortions and small floor noise can be obtained to realize high-fidelity audio amplifiers.

  6. Robust audio hashing for audio authentication watermarking

    Science.gov (United States)

    Zmudzinski, Sascha; Steinebach, Martin

    2008-02-01

    Current systems and protocols based on cryptographic methods for integrity and authenticity verification of media data do not distinguish between legitimate signal transformation and malicious tampering that manipulates the content. Furthermore, they usually provide no localization or assessment of the relevance of such manipulations with respect to human perception or semantics. We present an algorithm for a robust message authentication code in the context of content fragile authentication watermarking to verify the integrity of audio recodings by means of robust audio fingerprinting. Experimental results show that the proposed algorithm provides both a high level of distinction between perceptually different audio data and a high robustness against signal transformations that do not change the perceived information. Furthermore, it is well suited for the integration in a content-based authentication watermarking system.

  7. The Study of Audio Watermarking

    Institute of Scientific and Technical Information of China (English)

    王景; 唐晟

    2011-01-01

    This paper mainly introduced the basic knowledge of the digital watermarking and digital audio watermarking, including the definition of digital watermarking and digital audio watermarking, the embedding algorithm of digital audio watermarking and the com

  8. Generation of 130 W narrow-linewidth high-peak-power picosecond pulses directly from a compact Yb-doped single-stage fiber amplifier

    Science.gov (United States)

    Qi, Yaoyao; Yu, Haijuan; Zhang, Jingyuan; Wang, Lei; Zhang, Ling; Lin, Xuechun

    2015-09-01

    We report a compact, 130-W single-stage master oscillator power amplifier with a high peak power of 51.3 kW and a narrow spectral linewidth of 0.1 nm. The seed source is a single-mode, passively mode-locked solid-state laser at 1064 nm with an average power of 2 W. At a repetition rate of 73.5 MHz, the pulse duration is 30 ps. After amplification, it stretches to 34.5 ps. The experiment enables the optical-to-optical conversion efficiency to reach 75%. To the best of our knowledge, this is the first report of such a high-power, narrow spectral linewidth, high peak power picosecond-pulse fiber amplifier based on a continuous-wave, mode-locked solid-state seeding laser. No amplified spontaneous emission and stimulated Raman scattering were observed when the pump was increased.

  9. A compact diode-pumped pulsed Nd:YAG slab laser based on a master oscillator power amplifier configuration

    Science.gov (United States)

    Maleki, A.; Kavosh Tehrani, M.; Saghafifar, H.; Moghtader Dindarlu, M. H.; Ebadian, H.

    2016-02-01

    In this paper, the design and construction of a pulsed Nd:YAG laser is described. The structure of this laser is based on a master oscillator power amplifier system. A master oscillator is an electro-optical Q-switched Nd:YAG rod laser. Face-pumping is used for the excitation of the slab structure, and a double-pass method is designed for the amplification stages. Two Nd:YAG zigzag slabs are utilized as power amplification stages in this laser. The laser diodes are stacked in a compact configuration and are used for rod and slabs pumping. The total pump energy in the amplifier stages is 3200 mJ at 808 nm. The output pulse energy achieved at 1064 nm is about 850 mJ of 10 ns pulse duration corresponding to 26.5% optical-to-optical conversion efficiency. Moreover, this laser can generate pulse energies around 430 mJ at 532 nm. The dependence of the output energy of MOPA and second harmonic generation operations on different pulse repetition rates (PRRs) from 1 to 100 Hz has been investigated. Experimental results show that the maximum fluctuations of the output energies are about 2.5 and 4% for 1064 and 532 nm, respectively.

  10. Structure Learning in Audio

    DEFF Research Database (Denmark)

    Nielsen, Andreas Brinch

    By having information about the setting a user is in, a computer is able to make decisions proactively to facilitate tasks for the user. Two approaches are taken in this thesis to achieve more information about an audio environment. One approach is that of classifying audio, and a new approach...

  11. Roundtable Audio Discussion

    Directory of Open Access Journals (Sweden)

    Chris Bigum

    2007-01-01

    Full Text Available RoundTable on Technology, Teaching and Tools. This is a roundtable audio interview conducted by James Farmer, founder of Edublogs, with Anne Bartlett-Bragg (University of Technology Sydney and Chris Bigum (Deakin University. Skype was used to make and record the audio conference and the resulting sound file was edited by Andrew McLauchlan.

  12. Coupling of symmetric and asymmetric modes in a high-power, high-efficiency traveling-wave amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Banna, S. [Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 32000, (Israel); Schaechter, L. [Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 32000, (Israel); Nation, J. A. [School of Electrical Engineering and Laboratory of Plasma Studies, Cornell University Ithaca, New York 14853 (United States); Wang, P. [School of Electrical Engineering and Laboratory of Plasma Studies, Cornell University Ithaca, New York 14853 (United States)

    2000-04-01

    A three-dimensional model has been developed for the investigation of the coupling of symmetric (TM{sub 01}) and asymmetric (HEM{sub 11}) modes in a high-power, high-efficiency traveling-wave amplifier. In the framework of a simplified model it is shown that the coupling between these two modes is determined by a single parameter that depends on the beam characteristics. For a specific set of parameters corresponding to operation at 35 GHz, simulations indicate that an initial HEM{sub 11} power of 0.5 MW at the input end is sufficient to deflect electrons to the wall. The build-up of this parasitic mode is investigated over many round trips of the wave in the structure and a threshold criterion for self-sustain oscillation is established. Finally a way for suppressing the HEM{sub 11} mode is analyzed. (c) 2000 The American Physical Society.

  13. Evolution of Monolithic Technology for Wireless Communications: GaN MMIC Power Amplifiers For Microwave Radios

    Directory of Open Access Journals (Sweden)

    Vittorio Camarchia

    2014-09-01

    Full Text Available This paper presents the progress of monolithic technology for microwaveapplication, focusing on gallium nitride technology advances in the realization of integratedpower amplifiers. Three design examples, developed for microwave backhaul radios, areshown. The first design is a 7 GHz Doherty developed with a research foundry, while thesecond and the third are a 7 GHz Doherty and a 7–15 GHz dual-band combined poweramplifiers, both based on a commercial foundry process. The employed architectures, themain design steps and the pros and cons of using gallium nitride technology are highlighted.The measured performance demonstrates the potentialities of the employed technology, andthe progress in the accuracy, reliability and performance of the process.

  14. 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.

  15. On-chip power-combining techniques for watt-level linear power amplifiers in 0.18 μm CMOS

    Science.gov (United States)

    Zhixiong, Ren; Kefeng, Zhang; Lanqi, Liu; Cong, Li; Xiaofei, Chen; Dongsheng, Liu; Zhenglin, Liu; Xuecheng, Zou

    2015-09-01

    Three linear CMOS power amplifiers (PAs) with high output power (more than watt-level output power) for high data-rate mobile applications are introduced. To realize watt-level output power, there are two 2.4 GHz PAs using an on-chip parallel combining transformer (PCT) and one 1.95 GHz PA using an on-chip series combining transformer (SCT) to combine output signals of multiple power stages. Furthermore, some linearization techniques including adaptive bias, diode linearizer, multi-gated transistors (MGTR) and the second harmonic control are applied in these PAs. Using the proposed power combiner, these three PAs are designed and fabricated in TSMC 0.18 μm RFCMOS process. According to the measurement results, the proposed two linear 2.4 GHz PAs achieve a gain of 33.2 dB and 34.3 dB, a maximum output power of 30.7 dBm and 29.4 dBm, with 29% and 31.3% of peak PAE, respectively. According to the simulation results, the presented linear 1.95 GHz PA achieves a gain of 37.5 dB, a maximum output power of 34.3 dBm with 36.3% of peak PAE. Project supported by the National Natural Science Foundation of China (No. 61076030).

  16. Design procedure for millimeter-wave InP DHBT stacked power amplifiers

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Johansen, Tom Keinicke; Midili, Virginio

    2015-01-01

    (DHBTs). In this paper we describe the design methodology adopted and the results obtained at 86 GHz and 140 GHz. In the former case, 14.5 dBm of output power at the compression point, 14.5 dB of gain and 19.6 % of PAE are obtained from a four-transistor power cell. At 140 GHz, the same architecture...... gives 13.1 dBm of output power, 10.1 dB of gain and 13 % of PAE. To the best of the authors' knowledge, this is the first investigation of multi-level stacked PAs based on InP HBT technology....

  17. Design of low power common-gate low noise amplifier for 2.4 GHz wireless sensor network applications

    Institute of Scientific and Technical Information of China (English)

    Zhang Meng; Li Zhiqun

    2012-01-01

    This paper presents a differential low power low noise amplifier designed for the wireless sensor network (WSN) in a TSMC 0.18 μm RF CMOS process.A two-stage cross-coupling cascaded common-gate (CG)topology has been designed as the amplifier.The first stage is a capacitive cross-coupling topology.It can reduce the power and noise simultaneously.The second stage is a positive feedback cross-coupling topology,used to set up a negative resistance to enhance the equivalent Q factor of the inductor at the load to improve the gain of the LNA.A differential inductor has been designed as the load to achieve reasonable gain.This inductor has been simulated by the means of momentum electromagnetic simulation in ADS.A “double-π” circuit model has been built as the inductor model by iteration in ADS.The inductor has been fabricated separately to verify the model.The LNA has been fabricated and measured.The LNA works well centered at 2.44 GHz.The measured gain S21 is variable with high gain at 16.8 dB and low gain at 1 dB.The NF (noise figure) at high gain mode is 3.6 dB,the input referenced 1 dB compression point (IP1dB) is about-8 dBm and the IIP3 is 2 dBm at low gain mode.The LNA consumes about 1.2 mA current from 1.8 V power supply.

  18. A 115dB-DR Audio DAC with –61dBFS out-of-band noise

    NARCIS (Netherlands)

    Westerveld, Hugo; Schinkel, Daniël; Tuijl, van Ed

    2015-01-01

    Out-of-band noise (OBN) is troublesome in analog circuits that process the output of a noise-shaping audio DAC. It causes slewing in amplifiers and aliasing in sampling circuits like ADCs and class-D amplifiers. Nonlinearity in these circuits also causes cross-modulation of the OBN into the audio ba

  19. Twenty-watt average output power, picosecond thin-rod Yb:YAG regenerative chirped pulse amplifier with 200 mJ pulse energy

    OpenAIRE

    MATSUBARA, Shinichi; TANAKA, Motoharu; TAKAMA, Masaki; KAWATO, Sakae; Kobayashi, Takao

    2008-01-01

    A high-average power, laser-diode-pumped, picosecond-pulse regenerative chirpedpulse amplifier was developed by using the thin-rod Yb:YAG laser architecture. An averageoutput power of 20 W was achieved at a repetition rate of 100 kHz with an output pulse width of 2ps.

  20. High-power X- and Ka-band Gallium Nitride Amplifiers with Exceptional Efficiency Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Achieving very high-power amplification with maximum efficiency at X- and Ka-band is challenging using solid-state technology. Gallium Arsenide (GaAs) has been the...

  1. CMOS工艺射频功率放大器的实现与验证%Realization and verification of the CMOS technology RF power amplifier

    Institute of Scientific and Technical Information of China (English)

    谢君

    2011-01-01

    RF power amplifiers are key components in wireless devices, CaAs technology is widely used in the design and manufacture of RF power amplifier. But the CMOS technology has the very big superiority in the production maturity and the cost, this paper focuses on the problems that using CMOS technology to do the RF power amplifier, introduces the world's first mass product CMOS power amplifier and the special techniques used. Using a mature handset product, it replaces this power amplifier and the peripheral components, and finally carries on the contrast test with the original product.%射频功率放大器是无线设备的关键器件,GaAs工艺被广泛使用在射频功放的设计制造上.而CMOS工艺在生产成熟度和成本上有很大优势,主要关注用CMOS工艺来做射频功放的问题,介绍世界上第一颗量产的CMOS功放及其所使用的特殊技术.利用一款成熟的手机产品,替换这颗功放及外围器件,最后与原产品进行对比测试.

  2. On the jamming power allocation for secure amplify-and-forward relaying via cooperative jamming

    KAUST Repository

    Park, Kihong

    2013-09-01

    In this paper, we investigate secure communications in two-hop wireless relaying networks with one eavesdropper. To prevent the eavesdropper from intercepting the source message, the destination sends an intended jamming noise to the relay, which is referred to as cooperative jamming. This jamming noise helps protecting the source message from being captured reliably at the eavesdropper, while the destination cancels its self-intended noise. According to the channel information available at the destination, we derive three jamming power allocation strategies to minimize the outage probability of the secrecy rate. In addition, we derive analytic results quantifying the jamming power consumption of the proposed allocation methods. © 1983-2012 IEEE.

  3. Forensic audio watermark detection

    Science.gov (United States)

    Steinebach, Martin; Zmudzinski, Sascha; Petrautzki, Dirk

    2012-03-01

    Digital audio watermarking detection is often computational complex and requires at least as much audio information as required to embed a complete watermark. In some applications, especially real-time monitoring, this is an important drawback. The reason for this is the usage of sync sequences at the beginning of the watermark, allowing a decision about the presence only if at least the sync has been found and retrieved. We propose an alternative method for detecting the presence of a watermark. Based on the knowledge of the secret key used for embedding, we create a mark for all potential marking stages and then use a sliding window to test a given audio file on the presence of statistical characteristics caused by embedding. In this way we can detect a watermark in less than 1 second of audio.

  4. Introduction to AVS Audio

    Institute of Scientific and Technical Information of China (English)

    Hao-Jun Ai; Shui-Xian Chen; Rui-Min Hu

    2006-01-01

    This paper describes a general audio coding algorithm which has been recently standardized by AVS, China.The algorithm is based on a perceptual coding technique. The codec delivers near CD-quality audio at 128kb/s. This paper describes the coder structure in detail and discusses the reasons for specific design methods. A summary of the subjective test results are presented for the prototype codec. Comparison Mean Opinion Score (CMOS) test indicates that the quality of the AVS audio coder is comparable with MPEG Layer-3 audio coder. A real-time decoder was used for the characterization test,which is based on a 16-bit fixed-point DSP. The performance of the DSP solution was demonstrated, including computational complexity and storage characteristics.

  5. Power Allocation Strategies for Fixed-Gain Half-Duplex Amplify-and-Forward Relaying in Nakagami-m Fading

    KAUST Repository

    Zafar, Ammar

    2013-09-01

    In this paper, we study power allocation strategies for a fixed-gain amplify-and-forward relay network employing multiple relays. We consider two optimization problems for the relay network: 1) maximizing the end-to-end signalto- noise ratio (SNR) and 2) minimizing the total power consumption while maintaining the end-to-end SNR over a threshold value. We investigate these two problems for two relaying protocols of all-participate (AP) relaying and selective relaying and two cases of feedback to the relays, full and limited. We show that the SNR maximization problem is concave and the power minimization problem is convex for all protocols and feedback cases considered. We obtain closed-form expressions for the two problems in the case of full feedback and solve the problems through convex programming for limited feedback. Numerical results show the benefit of having full feedback at the relays for both optimization problems. However, they also show that feedback overhead can be reduced by having only limited feedback to the relays with only a small degradation in performance.

  6. Experimental results of a sheet-beam, high power, FEL amplifier with application to magnetic fusion research

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, S.; Destler, W.W.; Granatstein, V.L. [Univ. of Maryland, College Park, MD (United States)] [and others

    1995-12-31

    The experimental study of sheet-beam FELs as candidate millimeter-wave sources for heating magnetic fusion plasmas has achieved a major milestone. In a proof-of-principle, pulsed experiment, saturated FEL amplifier operation was achieved with 250 kW of output power at 86 GHz. Input microwave power was 1 kW, beam voltage was 450 kV and beam current was 17 A. The planar wiggler had a peak value of 3.8 kG, a period of 0.96 cm and was 71 cm long. The linear gain of 30 dB, saturated gain of 24 dB and saturated efficiency of 3% all are in good agreement with theoretical prediction. Follow-on work would include development of a thermionic sheet-beam electron-gun compatible with CW FEL operation, adding a section of tapered wiggler to increase the output power to levels in excess of 1 megawatt, and increasing the FEL frequency.

  7. Analysis of the third harmonic for class-F power amplifiers with an I-V knee effect

    Science.gov (United States)

    Zhao, Bo-Chao; Lu, Yang; Wei, Jia-Xing; Dong, Liang; Wang, Yi; Cao, Meng-Yi; Ma, Xiao-Hua; Hao, Yue

    2015-05-01

    The appearance of third-generation semiconductors represented by gallium nitride (GaN) material greatly improves the output power of a power amplifier (PA), but the efficiency of the PA needs to be further improved. The Class-F PA reduces the overlap of drain voltage and current by tuning harmonic impedance so that high efficiency is achieved. This paper begins with the principle of class-F PA, regards the third harmonic voltage as an independent variable, analyzes the influence of the third harmonic on fundamental, and points out how drain efficiency and output power vary with the third harmonic voltage with an I-V knee effect. Finally, the best third harmonic impedance is found mathematically. We compare our results with the Loadpull technique in advanced design system environment and conclude that an optimized third harmonic impedance is open in an ideal case, while it is not at an open point with the I-V knee effect, and the drain efficiency with optimized third harmonic impedance is 4% higher than that with the third harmonic open.

  8. Intensity noise reduction of a high-power nonlinear femtosecond fiber amplifier based on spectral-breathing self-similar parabolic pulse evolution

    Science.gov (United States)

    Wang, Sijia; Liu, Bowen; Song, Youjian; Hu, Minglie

    2016-04-01

    We report on a simple passive scheme to reduce the intensity noise of high-power nonlinear fiber amplifiers by use of the spectral-breathing parabolic evolution of the pulse amplification with an optimized negative initial chirp. In this way, the influences of amplified spontaneous emission (ASE) on the amplifier intensity noise can be efficiently suppressed, owing to the lower overall pulse chirp, shorter spectral broadening distance, as well as the asymptotic attractive nature of self-similar pulse amplification. Systematic characterizations of the relative intensity noise (RIN) of a free-running nonlinear Yb-doped fiber amplifier are performed over a series of initial pulse parameters. Experiments show that the measured amplifier RIN increases respect to the decreased input pulse energy, due to the increased amount of ASE noise. For pulse amplification with a proper negative initial chirp, the increase of RIN is found to be smaller than with a positive initial chirp, confirming the ASE noise tolerance of the proposed spectral-breathing parabolic amplification scheme. At the maximum output average power of 27W (25-dB amplification gain), the incorporation of an optimum negative initial chirp (-0.84 chirp parameter) leads to a considerable amplifier root-mean-square (rms) RIN reduction of ~20.5% (integrated from 10 Hz to 10 MHz Fourier frequency). The minimum amplifier rms RIN of 0.025% (integrated from 1 kHz to 5 MHz Fourier frequency) is obtained along with the transform-limited compressed pulse duration of 55fs. To our knowledge, the demonstrated intensity noise performance is the lowest RIN level measured from highpower free-running femtosecond fiber amplifiers.

  9. 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.

  10. DOUBLE-BOOST DC-AC CONVERTER WITH SLIDING-MODE CONTROL FOR PORTABLE AUDIO

    DEFF Research Database (Denmark)

    Bolten Maizonave, Gert; Andersen, Michael Andreas E.; Kjærgaard, Claus;

    2009-01-01

    The double-boost topology is studied for operation as a dc-ac converter and single stage audio amplifier. A sliding-mode controller is designed in order to achieve fast enough response for the whole audio frequency range. Symmetric, asymmetric and interleaved operation modes are analyzed....

  11. Parametric Audio Based Decoder and Music Synthesizer for Mobile Applications

    NARCIS (Netherlands)

    Oomen, A.W.J.; Szczerba, M.Z.; Therssen, D.

    2011-01-01

    This paper reviews parametric audio coders and discusses novel technologies introduced in a low-complexity, low-power consumption audiodecoder and music synthesizer platform developed by the authors. Thedecoder uses parametric coding scheme based on the MPEG-4 Parametric Audio standard. In order to

  12. A Novel Predistorter Design for Nonlinear Power Amplifier with Memory Effects in OFDM Communication Systems Using Orthogonal Polynomials

    Science.gov (United States)

    Zhang, Yitao; Araki, Kiyomichi

    Orthogonal frequency division multiplexing (OFDM) signals have high peak-to-average power ratio (PAPR) and cause large nonlinear distortions in power amplifiers (PAs). Memory effects in PAs also become no longer ignorable for the wide bandwidth of OFDM signals. Digital baseband predistorter is a highly efficient technique to compensate the nonlinear distortions. But it usually has many parameters and takes long time to converge. This paper presents a novel predistorter design using a set of orthogonal polynomials to increase the convergence speed and the compensation quality. Because OFDM signals are approximately complex Gaussian distributed, the complex Hermite polynomials which have a closed-form expression can be used as a set of orthogonal polynomials for OFDM signals. A differential envelope model is adopted in the predistorter design to compensate nonlinear PAs with memory effects. This model is superior to other predistorter models in parameter number to calculate. We inspect the proposed predistorter performance by using an OFDM signal referred to the IEEE 802.11a WLAN standard. Simulation results show that the proposed predistorter is efficient in compensating memory PAs. It is also demonstrated that the proposal acquires a faster convergence speed and a better compensation effect than conventional predistorters.

  13. Research and Design of Asymmetric Doherty Power Amplifier for WiMAX%面向WiMAX的非对称Doherty功放研究与设计

    Institute of Scientific and Technical Information of China (English)

    杜学坤; 南敬昌; 李蕾; 李厚儒

    2013-01-01

    To deal with limitations in WiMAX application of classic Doherty structure,a method combining high power transistor with load pull technology was proposed,which solved classic Doherty's problem that its actual output power is less than saturated output power.An asymmetric Doherty power amplifier was designed for 3.4-3.6 GHz band WiMAX base station,which had a power added efficiency (PAE) above 45% for a 9.5 dB power back-off.Load modulation effect of the peaking power amplifier was improved and power leakage from main power amplifier to auxiliary power amplifier was reduced by using pre-positive delay line and output offset line.%针对经典Doherty结构在WiMAX应用中存在的某些缺陷,提出了一种大功率管和负载牵引技术相结合的方法,解决了经典Doherty实际输出功率小于其饱和功率的问题.设计了一款应用于3.4~3.6 GHz频段WiMAX基站的非对称Doherty功率放大器,在功率回退9.5dB的范围内,功率附加效率(PAE)均在45%以上.采用添加前置延迟线和输出补偿线的方案,改善了峰值功放的负载调制效应,降低了载波功放向峰值功放的功率泄露.

  14. Thermal management of space-based, high-power solid-state RF amplifiers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rose, M.F.; Chow, L.C.; Johnson, J.H.

    1990-08-01

    The advanced weapons concepts envisioned by the SDIO employed a wide array of highly energetic devices, which due to inefficiencies, generate large quantities of waste heat. Power and thermal management are integrally related. In the vacuum of space, disposing of waste energy is a major problem which can contribute as much as 50% to the overall spacecraft mass and volume. The problem becomes more acute as the temperature at which the energy must be rejected is lowered. In an earlier study, thermal management issues associated with megawatt class RF microwave tubes were explored to determine if there were simple, approximately mass neutral schemes which might be adapted to dispose of the waste energy generated within a tube collector operating in space. The assumptions for that study were: (1) Tubes were in the megawatt class-70% efficient for single simple collector and 90% efficient for depressed collectors, (2) On-board, super critical hydrogen was available at a pressure of 35 bars and a temperature of 35 K. (3) The largest single event run time was 500 seconds. (4) The device would be dormant for long periods of time, be required to become active in tens of seconds followed by long periods of dormancy. (5) The only allowable effluent is hydrogen. (6) System impact must be minimal.

  15. A CMOS power-efficient low-noise current-mode front-end amplifier for neural signal recording.

    Science.gov (United States)

    Wu, Chung-Yu; Chen, Wei-Ming; Kuo, Liang-Ting

    2013-04-01

    In this paper, a new current-mode front-end amplifier (CMFEA) for neural signal recording systems is proposed. In the proposed CMFEA, a current-mode preamplifier with an active feedback loop operated at very low frequency is designed as the first gain stage to bypass any dc offset current generated by the electrode-tissue interface and to achieve a low high-pass cutoff frequency below 0.5 Hz. No reset signal or ultra-large pseudo resistor is required. The current-mode preamplifier has low dc operation current to enhance low-noise performance and decrease power consumption. A programmable current gain stage is adopted to provide adjustable gain for adaptive signal scaling. A following current-mode filter is designed to adjust the low-pass cutoff frequency for different neural signals. The proposed CMFEA is designed and fabricated in 0.18-μm CMOS technology and the area of the core circuit is 0.076 mm(2). The measured high-pass cutoff frequency is as low as 0.3 Hz and the low-pass cutoff frequency is adjustable from 1 kHz to 10 kHz. The measured maximum current gain is 55.9 dB. The measured input-referred current noise density is 153 fA /√Hz , and the power consumption is 13 μW at 1-V power supply. The fabricated CMFEA has been successfully applied to the animal test for recording the seizure ECoG of Long-Evan rats.

  16. Doping management for high-power fiber lasers: 100 W, few-picosecond pulse generation from an all-fiber-integrated amplifier.

    Science.gov (United States)

    Elahi, P; Yılmaz, S; Akçaalan, O; Kalaycıoğlu, H; Oktem, B; Senel, C; Ilday, F Ö; Eken, K

    2012-08-01

    Thermal effects, which limit the average power, can be minimized by using low-doped, longer gain fibers, whereas the presence of nonlinear effects requires use of high-doped, shorter fibers to maximize the peak power. We propose the use of varying doping levels along the gain fiber to circumvent these opposing requirements. By analogy to dispersion management and nonlinearity management, we refer to this scheme as doping management. As a practical first implementation, we report on the development of a fiber laser-amplifier system, the last stage of which has a hybrid gain fiber composed of high-doped and low-doped Yb fibers. The amplifier generates 100 W at 100 MHz with pulse energy of 1 μJ. The seed source is a passively mode-locked fiber oscillator operating in the all-normal-dispersion regime. The amplifier comprises three stages, which are all-fiber-integrated, delivering 13 ps pulses at full power. By optionally placing a grating compressor after the first stage amplifier, chirp of the seed pulses can be controlled, which allows an extra degree of freedom in the interplay between dispersion and self-phase modulation. This way, the laser delivers 4.5 ps pulses with ~200 kW peak power directly from fiber, without using external pulse compression.

  17. 1.2 MW peak power, all-solid-state picosecond laser with a microchip laser seed and a high gain single-passing bounce geometry amplifier

    Science.gov (United States)

    Wang, Chunhua; Shen, Lifeng; Zhao, Zhiliang; Liu, Bin; Jiang, Hongbo; Chen, Jun; Liu, Chong

    2016-11-01

    A semiconductor saturable absorber mirror (SESAM) based passively Q-switched microchip Nd:YVO4 seed laser with pulse duration of 90 ps at repetition rate of 100 kHz is amplified by single-passing a Nd:YVO4 bounce amplifier with varying seed input power from 20 μW to 10 mW. The liquid pure metal greasy thermally conductive material is used to replace the traditional thin indium foil as the thermal contact material for better heat load transfer of the Nd:YVO4 bounce amplifier. Temperature distribution at the pump surface is measured by an infrared imager to compare with the numerically simulated results. A highest single-passing output power of 11.3 W is obtained for 10 mW averaged seed power, achieving a pulse peak power of ~1.25 MW and pulse energy of ~113 μJ. The beam quality is well preserved with M2 ≤1.25. The simple configuration of this bounce laser amplifier made the system flexible, robust and cost-effective, showing attractive potential for further applications.

  18. Dual-wavelength high-power diode laser system based on an external-cavity tapered amplifier with tunable frequency difference

    DEFF Research Database (Denmark)

    Chi, Mingjun; Jensen, Ole Bjarlin; Petersen, Paul Michael

    2012-01-01

    A dual-wavelength high-power semiconductor laser system based on a tapered amplifier with double-Littrow external cavity is demonstrated around 800 nm. The two wavelengths can be tuned individually, and the frequency difference of the two wavelengths is tunable from 0.5 to 10.0 THz. To our knowle...

  19. One watt gallium arsenide class-E power amplifier with a thin-film bulk acoustic resonator filter embedded in the output network

    Directory of Open Access Journals (Sweden)

    Kyle Holzer

    2015-05-01

    Full Text Available Integration of a class-E power amplifier (PA and a thin-film bulk acoustic wave resonator (FBAR filter is shown to provide high power added efficiency in addition to superior out-of-band spectrum suppression. A discrete gallium arsenide pseudomorphic high-electron-mobility transistor is implemented to operate as a class-E amplifier from 2496 to 2690 MHz. The ACPF7041 compact bandpass FBAR filter is incorporated to replace the resonant LC tank in a traditional class-E PA. To reduce drain voltage stress, the supply choke is replaced by a finite inductance. The fabricated PA provides up to 1 W of output power with a peak power added efficiency (PAE of 58%. The improved out-of-band spectrum filtering is compared to a traditional class-E with discrete LC resonant filtering. Such PAs can be combined with linearisation techniques to reduce out-of-band emissions.

  20. SIMULATIVE ANALYSIS OF OSNR AND RECEIVED ELECTRIC RF POWER OF A ROF SYSTEM HAVING VARIABLE FIBER LENGTH, USING DIFFERENT MODULATION TECHNIQUES AND OPTICAL AMPLIFIERS

    Directory of Open Access Journals (Sweden)

    KARANBIR SINGH,

    2011-05-01

    Full Text Available In this paper, we analyzed OSNR and received electric RF power of a RoF communication system having variable fiber length, using direct and external modulation techniques and different optical amplifiers. In this work, we have compared and measured the OSNR and received optical power of the RoF system for different modulation techniques, i.e. direct and external modulation. Further, we also compared the received electric RF power for variable fiber lengths for direct and external modulation using different optical amplifiers, i.e. EDFAand SOA. We observe an increase of –11 dB (approx. in the received RF power for External modulation compared to direct modulation with EDFA.

  1. Perceptual Audio Hashing Functions

    Directory of Open Access Journals (Sweden)

    Emin Anarım

    2005-07-01

    Full Text Available Perceptual hash functions provide a tool for fast and reliable identification of content. We present new audio hash functions based on summarization of the time-frequency spectral characteristics of an audio document. The proposed hash functions are based on the periodicity series of the fundamental frequency and on singular-value description of the cepstral frequencies. They are found, on one hand, to perform very satisfactorily in identification and verification tests, and on the other hand, to be very resilient to a large variety of attacks. Moreover, we address the issue of security of hashes and propose a keying technique, and thereby a key-dependent hash function.

  2. High-average-power 2 μm few-cycle optical parametric chirped pulse amplifier at 100 kHz repetition rate.

    Science.gov (United States)

    Shamir, Yariv; Rothhardt, Jan; Hädrich, Steffen; Demmler, Stefan; Tschernajew, Maxim; Limpert, Jens; Tünnermann, Andreas

    2015-12-01

    Sources of long wavelengths few-cycle high repetition rate pulses are becoming increasingly important for a plethora of applications, e.g., in high-field physics. Here, we report on the realization of a tunable optical parametric chirped pulse amplifier at 100 kHz repetition rate. At a central wavelength of 2 μm, the system delivered 33 fs pulses and a 6 W average power corresponding to 60 μJ pulse energy with gigawatt-level peak powers. Idler absorption and its crystal heating is experimentally investigated for a BBO. Strategies for further power scaling to several tens of watts of average power are discussed.

  3. A 3.4-3.6 GHz power amplifier in an InGaP/GaAs HBT

    Energy Technology Data Exchange (ETDEWEB)

    Hao Mingli; Zhang Zongnan; Zhang Haiying, E-mail: haomingli@ime.ac.cn [Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029 (China)

    2011-09-15

    This paper presents a 3.4-3.6 GHz power amplifier (PA) designed and implemented in InGaP/GaAs HBT technology. By optimizing the off-chip output matching network and designing an extra input-matching circuit on the PCB, several problems are resolved, such as resonant frequency point migration, worse matching and lower gain caused by parasitics inside and outside of the chip. Under V{sub cc} = 4.3 V and V{sub bias} = 3.3 V, a P{sub 1dB} of 27.1 dBm has been measured at 3.4 GHz with a PAE of 25.8%, the 2nd and 3rd harmonics are -64 dBc and -51 dBc, respectively. In addition, this PA shows a linear gain more than 28 dB with S{sub 11} < -12.4 dB and S{sub 22} < -7.4 dB in 3.4-3.6 GHz band. (semiconductor devices)

  4. Analysis of the effectiveness of power equations in the description of electron-wave processes in the amplifier model based on the smith-purcell effect

    Directory of Open Access Journals (Sweden)

    A.A. Rybalko

    2009-01-01

    Full Text Available We present the comparative analysis of different approximations used to obtain the dispersion equations in the form of power polynomials, which allow to describe the electron-wave processes in the amplifier system an open waveguide with periodic structure and an electron beam. Shown, that the amplifier model described by the analytical third- and seventh-order dispersion equations is the most evident one from the physical point of view. These equations allow to take into account the basic characteristics of electrodynamic system and electron beam, which interacts with a bulk wave of the investigated quasi-optical system.

  5. Instabilities in RF-power amplifiers caused by a self-oscillation in the transistor bias network

    DEFF Research Database (Denmark)

    Vidkjær, Jens

    1976-01-01

    This paper describes a self-oscillation in the bias network of an amplifier which is commonly used for the output stage in mobile transmitters. It is demonstrated how some often observed spurious oscillations may be related to the self-oscillation and a method for stabilizing the amplifier is der...

  6. 宽带GaN功率放大器的建模与预失真%Modeling and Pre-distortion of Broadband GaN Power Amplifier

    Institute of Scientific and Technical Information of China (English)

    丁元明; 李正杰; 王雪

    2012-01-01

    对正交频分复用传输系统中宽带GaN功率放大器的建模与预失真线性化方法进行研究.应用一个带有记忆的多项式模型来建模GaN功率放大器及其逆特性,并通过递推最小二乘法(RLS)辨识模型参数,然后利用预失真间接结构实现了GaN功率放大器的预失真器.最后,仿真验证预失真方法的有效性,结果表明记忆多项式模型可以对GaN功率放大器进行建模并实现线性化.%A modeling and predistortion linearization method is proposed for broadband GaN power amplifiers in the orthogonal frequency division multiplexing transmission (OFDM) system. Apply a memory polynomial model to modeling GaN power amplifier and its inverse characteristics, and by using the recursive least squares (RLS) identify the model parameters, and then the predistortion indirect structure realize a predistorter of the GaN amplifier. Finally, simulation results prove the effectiveness of the predistortion method, and the results show that memory polynomial model can be modeled on GaN power amplifier and realize the linearization.

  7. Embedded Audio Without Beeps

    DEFF Research Database (Denmark)

    Overholt, Daniel; Møbius, Nikolaj Friis

    2014-01-01

    software environments for audio processing) via innovative interfaces that send real-time inputs to such software running on a laptop, mobile device, or small Linux board (e.g., Raspberry Pi or Beagleboard). Basic hardware will be provided, but participants are also encouraged to bring related equipment...

  8. Multipurpose audio watermarking algorithm

    Institute of Scientific and Technical Information of China (English)

    Ning CHEN; Jie ZHU

    2008-01-01

    To make audio watermarking accomplish both copyright protection and content authentication with localization, a novel multipurpose audio watermarking scheme is proposed in this paper. The zero-watermarking idea is introduced into the design of robust watermarking algorithm to ensure the transparency and to avoid the interference between the robust watermark and the semi-fragile watermark. The property of natural audio that the VQ indices of DWT-DCT coefficients among neighboring frames tend to be very similar is utilized to extract essential feature from the host audio, which is then used for watermark extraction. And, the chaotic mapping based semi-fragile watermark is embedded in the detail wavelet coefficients based on the instantaneous mixing model of the independent component analysis (ICA) system. Both the robust and semi-fragile watermarks can be extracted blindly and the semi-fragile watermarking algorithm can localize the tampering accurately. Simulation results demonstrate the effectiveness of our algorithm in terms of transparency, security, robustness and tampering localization ability.

  9. Audio Feedback -- Better Feedback?

    Science.gov (United States)

    Voelkel, Susanne; Mello, Luciane V.

    2014-01-01

    National Student Survey (NSS) results show that many students are dissatisfied with the amount and quality of feedback they get for their work. This study reports on two case studies in which we tried to address these issues by introducing audio feedback to one undergraduate (UG) and one postgraduate (PG) class, respectively. In case study one…

  10. Categorizing Video Game Audio

    DEFF Research Database (Denmark)

    Westerberg, Andreas Rytter; Schoenau-Fog, Henrik

    2015-01-01

    This paper dives into the subject of video game audio and how it can be categorized in order to deliver a message to a player in the most precise way. A new categorization, with a new take on the diegetic spaces, can be used a tool of inspiration for sound- and game-designers to rethink how they ...

  11. 8.5-W mode-locked Yb:Lu$_{1.5}$Y$_{1.5}$Al$_5$O$_{12}$ laser with master oscillator power amplifiers

    CERN Document Server

    Wang, Fuyong; Xie, Guoqiang; Yuan, Peng; Qian, Liejia; Xu, Xiaodong; Xu, Jun

    2014-01-01

    We report on a diode-pumped passively mode-locked Yb:Lu$_{1.5}$Y$_{1.5}$Al$_5$O$_{12}$ (Yb:LuYAG) laser for the first time to our knowledge. With the mixed crystal of Yb:LuYAG as gain medium, the mode-locked laser generated 2.2 W of average output power with a repetition rate of 83.9 MHz and pulse duration of 2.2 ps at the wavelength of 1030 nm. In order to obtain higher output power, the output from the mode-locked oscillator was further amplified to 8.5 W by two-stage single-pass amplifiers. The high-power picosecond laser is very useful for applications such as pumping of mid-infrared optical parametric oscillators, material micro-processing, and UV light generation, etc.

  12. A high-linearity InGaP/GaAs HBT power amplifier for IEEE 802.11a/n

    Institute of Scientific and Technical Information of China (English)

    Cui Jie; Chen Lei; Kang Chunlei; Shi Jia; Zhang Xuguang; Ai Baoli; Liu Yi

    2013-01-01

    A three-stage 4.8-6 GHz monolithic power amplifier (PA) compatible with IEEE 802.11 a/n designed based on an advanced 2 μm InGaP/GaAs hetero-junction bipolar transistor (HBT) process is presented.The PA integrates input matching and closed-loop power control circuits on chip.Under 3.3 V DC bias,the amplifier achieves a ~31 dB small signal gain,excellent wide band input and output matching among overall 1.2 GHz bandwidth,and up to 24.5 dBm linear output power below EVM 3% with IEEE 802.1 la 64QAM OFDM input signal.

  13. The audio expert everything you need to know about audio

    CERN Document Server

    Winer, Ethan

    2012-01-01

    The Audio Expert is a comprehensive reference that covers all aspects of audio, with many practical, as well as theoretical, explanations. Providing in-depth descriptions of how audio really works, using common sense plain-English explanations and mechanical analogies with minimal math, the book is written for people who want to understand audio at the deepest, most technical level, without needing an engineering degree. It's presented in an easy-to-read, conversational tone, and includes more than 400 figures and photos augmenting the text.The Audio Expert takes th

  14. The System Identification and Model Design of Linear Power Amplifier%线性功率放大器模型设计及其系统辨识

    Institute of Scientific and Technical Information of China (English)

    谢珺耀; 李久芳

    2011-01-01

    The linear power amplifier can control an ideal state to output voltage and current,so it is widely used in industrial control area.Such as programming voltage source,programming current source,voice motor driver,linear motor driver,etc.The linear power amplifier is mainly based on the power operational amplifier,in performance close to the ideal operational amplifier model,with a high dynamic voltage and current range.It is easy to enhance driving current.In this paper,using the design of the amplifier model,the calculation of transfer function,system performance analysis,simulation and identification with MATLAB to fully verify system performance,and thus make the best system design.%线性功率放大器可对其输出电压和电流进行比较理想的控制,因此在工业控制场合得到了广泛的应用。如可编程电压源、可编程电流源、音圈电机驱动、直线电机驱动等。线性功率放大器主要以功率运算放大器为基础,在性能上接近理想的运算放大器的同时具有较高的动态电压和动态电流范围,如果要进行驱动电流提升,也很容易实现。从放大器的模型设计、传递函数计算、系统性能分析和MATLAB仿真辨识来全面验证系统设计的指标性能,从而做出最佳系统设计。

  15. On Optimal Truncated Biharmonic Current Waveforms for Class-F and Inverse Class-F Power Amplifiers

    Directory of Open Access Journals (Sweden)

    Anamarija Juhas

    2017-01-01

    Full Text Available In this paper, two-parameter families of periodic current waveforms for class-F and inverse class-F power amplifiers (PAs are considered. These waveforms are obtained by truncating cosine waveforms composed of dc component and fundamental and either second (k=2 or third (k=3 harmonic. In each period, waveforms are truncated to become zero outside of a prescribed interval (so-called conduction angle. The considered families of waveforms include both discontinuous and continuous waveforms. Fourier series expansion of truncated waveform contains an infinite number of harmonics, although a number of harmonics may be missing. Taking into account common assumptions that for class-F PA the third (n=3 harmonic is missing in current waveform and for inverse class-F PA the second (n=2 harmonic is missing in current waveform, we consider the following four cases: (i n=k=3, (ii n=3, k=2, (iii n=k=2, and (iv n=2, k=3. We show that, in each of these cases, current waveform enabling maximal efficiency (optimal waveform of class-F and inverse class-F PA is continuous for all conduction angles of practical interest. Furthermore, we provide closed-form expressions for parameters of optimal current waveforms and maximal efficiency of class-F (inverse class-F PA in terms of conduction angle only. Two case studies of practical interest for PA design, involving suboptimal current waveforms, along with the results of nonlinear simulation of inverse class-F PA, are also presented.

  16. Design and realization of digital audio equalizer based on MCU and FPAA

    Institute of Scientific and Technical Information of China (English)

    Zhou Ping; Liu Zhuo; Xia Liang

    2008-01-01

    In analog audio equalizer, the filters are constructed by op-amplifiers and discrete components. Being influenced by its discrete capabilities, audio equalizer has many disadvantages. Meanwhile, pure digital audio equalizer has got better performance and stability, but its cost and price are too high. So digital audio equalizer only has its application in upscale domain. A new design method for audio equalizer is proposed, which attempts to design and realize a high precision and high SNR (signal noise ratio) digital audio equalizer system based on field programmable analog array (FPAA) and micro-controller unit. This design confirms that design speed and performance will be greatly enhanced when FPAA technology is applied to analog design domain.

  17. Audible Aliasing Distortion in Digital Audio Synthesis

    Directory of Open Access Journals (Sweden)

    J. Schimmel

    2012-04-01

    Full Text Available This paper deals with aliasing distortion in digital audio signal synthesis of classic periodic waveforms with infinite Fourier series, for electronic musical instruments. When these waveforms are generated in the digital domain then the aliasing appears due to its unlimited bandwidth. There are several techniques for the synthesis of these signals that have been designed to avoid or reduce the aliasing distortion. However, these techniques have high computing demands. One can say that today's computers have enough computing power to use these methods. However, we have to realize that today’s computer-aided music production requires tens of multi-timbre voices generated simultaneously by software synthesizers and the most of the computing power must be reserved for hard-disc recording subsystem and real-time audio processing of many audio channels with a lot of audio effects. Trivially generated classic analog synthesizer waveforms are therefore still effective for sound synthesis. We cannot avoid the aliasing distortion but spectral components produced by the aliasing can be masked with harmonic components and thus made inaudible if sufficient oversampling ratio is used. This paper deals with the assessment of audible aliasing distortion with the help of a psychoacoustic model of simultaneous masking and compares the computing demands of trivial generation using oversampling with those of other methods.

  18. Development of Power Amplifier Based on PA52 Chip%基于大功率运放PA52的功率放大器研制

    Institute of Scientific and Technical Information of China (English)

    杨勇; 李国富; 刘之方; 李永亮

    2013-01-01

      针对串补用火花间隙的自放电特性研究,利用大电流MOSFET运放PA52设计与开发了适合火花间隙自放电试验电源的新型大功率放大器。本文理论分析了功率放大器工作效率、输出电压和系统电源的确定关系,采用了DC-DC隔离电源模块提升输出电压幅摆,设计了负反馈保护电路限制电流提高功率放大器的安全性。该功率放大器驱动20(纯阻性负载时,单端到地输出电压为-80V~+80V,电压增益20dB,电流可达4A,最大功率200W,最大效率75.3%。实验与分析表明,该功率放大器非线性失真小,带负载能力强,能满足用于研究火花间隙自放电特性的试验电源的要求。%In order to study the self-discharge characteristics of the spark gap of series compensation device, a high power amplifier which is suitable for power supply of spark gap self-discharge test is developed by utilizing a high current MOSFET power operational chip PA52. Therefore, this paper analyzed the definite relationship between the amplifier’s efficiency, output voltage and system power supply, adopted DC-DC isolated power supply modules to enhance the output voltage swing, and designed a negative feedback protection circuit to limit the current to improve the security of the power amplifier. This power amplifier can provide a maximum single-ended output voltage of 160V (peak to peak), a voltage gain of 20dB, a maximum current of 4A, a maximum power of 200W and a maximum efficiency of 75.3% with a 20(pure resistant load. The experimental results show that the power amplifier can meet the requirements of the test power supply for studying spark gap self-discharge characteristic due to its small nonlinear distortion, powerful load capacity and high efficiency.

  19. A C-band 55%PAE high gain two-stage power amplifier based on AlGaN/GaN HEMT

    Institute of Scientific and Technical Information of China (English)

    郑佳欣; 马晓华; 卢阳; 赵博超; 张宏鹤; 张濛; 曹梦逸; 郝跃

    2015-01-01

    A C-band high efficiency and high gain two-stage power amplifier based on AlGaN/GaN high electron mobility transistor (HEMT) is designed and measured in this paper. The input and output impedances for the optimum power-added efficiency (PAE) are determined at the fundamental and 2nd harmonic frequency ( f0 and 2 f0). The harmonic manipulation networks are designed both in the driver stage and the power stage which manipulate the second harmonic to a very low level within the operating frequency band. Then the inter-stage matching network and the output power combining network are calculated to achieve a low insertion loss. So the PAE and the power gain is greatly improved. In an operation frequency range of 5.4 GHz–5.8 GHz in CW mode, the amplifier delivers a maximum output power of 18.62 W, with a PAE of 55.15%and an associated power gain of 28.7 dB, which is an outstanding performance.

  20. A C-band 55% PAE high gain two-stage power amplifier based on AlGaN/GaN HEMT

    Science.gov (United States)

    Zheng, Jia-Xin; Ma, Xiao-Hua; Lu, Yang; Zhao, Bo-Chao; Zhang, Hong-He; Zhang, Meng; Cao, Meng-Yi; Hao, Yue

    2015-10-01

    A C-band high efficiency and high gain two-stage power amplifier based on AlGaN/GaN high electron mobility transistor (HEMT) is designed and measured in this paper. The input and output impedances for the optimum power-added efficiency (PAE) are determined at the fundamental and 2nd harmonic frequency (f0 and 2f0). The harmonic manipulation networks are designed both in the driver stage and the power stage which manipulate the second harmonic to a very low level within the operating frequency band. Then the inter-stage matching network and the output power combining network are calculated to achieve a low insertion loss. So the PAE and the power gain is greatly improved. In an operation frequency range of 5.4 GHz-5.8 GHz in CW mode, the amplifier delivers a maximum output power of 18.62 W, with a PAE of 55.15% and an associated power gain of 28.7 dB, which is an outstanding performance. Project supported by the National Key Basic Research Program of China (Grant No. 2011CBA00606), Program for New Century Excellent Talents in University, China (Grant No. NCET-12-0915), and the National Natural Science Foundation of China (Grant No. 61334002).

  1. AC-3 audio coder

    Science.gov (United States)

    Todd, Craig

    1995-12-01

    AC-3 is a system for coding up to 5.1 channels of audio into a low bit-rate data stream. High quality may be obtained with compression ratios approaching 12-1 for multichannel audio programs. The high compression ratio is achieved by methods which do not increase decoder memory, and thus cost. The methods employed include: the transmission of a high frequency resolution spectral envelope; and a novel forward/backward adaptive bit allocation algorithm. In order to satisfy practical requirements of an emissions coder, the AC-3 syntax includes a number of features useful to broadcasters and consumers. These features include: loudness uniformity between programs; dynamic range control; and broadcaster control of downmix coefficients. The AC-3 coder has been formally selected for inclusion of the U.S. HDTV broadcast standard, and has been informally selected for several additional applications.

  2. Nonlinear Properties of Power Amplifiers and Digital Predistortion%功率放大器非线性特性及预失真

    Institute of Scientific and Technical Information of China (English)

    付丽萍

    2015-01-01

    建立了无记忆的功放的非线性模型,分析功率放大器的非线性特性、产生失真的情况及误差。设计无记忆的预失真系统,用于抵消因功放造成的非线性干扰,并实现从输入到输出的线性化。基于距离本抽样值较远的不同间隔的几个抽样值来收集功放记忆效应,建立具有稀疏延迟抽头的有记忆的功放非线性模型。改进Volterra级数预失真模型,辨识多项式、建立相应的辨识模型,采用间接地辨识方法进行预失真模型的设计,并通过MATLAB建模仿真,验证设计模型的有效性。%This paper main study the nonlinear model of memoryless power amplifiers is established,the nonlinear properties of power amplifiers and the situation of producing the predistortion and the error are analyzing,and the pre-distortion system of memoryless,which can be used to offset the nonlinear disturbance of due to the power amplifier and implementing the linearization of input to the output is designed.Based on the memory effect of col ecting by several sample values which far from the sampling values and in the different interval,the model of memory power amplifier with the sparse tap delay mem-ory is established in this paper.

  3. Efficient audio signal processing for embedded systems

    Science.gov (United States)

    Chiu, Leung Kin

    As mobile platforms continue to pack on more computational power, electronics manufacturers start to differentiate their products by enhancing the audio features. However, consumers also demand smaller devices that could operate for longer time, hence imposing design constraints. In this research, we investigate two design strategies that would allow us to efficiently process audio signals on embedded systems such as mobile phones and portable electronics. In the first strategy, we exploit properties of the human auditory system to process audio signals. We designed a sound enhancement algorithm to make piezoelectric loudspeakers sound ”richer" and "fuller." Piezoelectric speakers have a small form factor but exhibit poor response in the low-frequency region. In the algorithm, we combine psychoacoustic bass extension and dynamic range compression to improve the perceived bass coming out from the tiny speakers. We also developed an audio energy reduction algorithm for loudspeaker power management. The perceptually transparent algorithm extends the battery life of mobile devices and prevents thermal damage in speakers. This method is similar to audio compression algorithms, which encode audio signals in such a ways that the compression artifacts are not easily perceivable. Instead of reducing the storage space, however, we suppress the audio contents that are below the hearing threshold, therefore reducing the signal energy. In the second strategy, we use low-power analog circuits to process the signal before digitizing it. We designed an analog front-end for sound detection and implemented it on a field programmable analog array (FPAA). The system is an example of an analog-to-information converter. The sound classifier front-end can be used in a wide range of applications because programmable floating-gate transistors are employed to store classifier weights. Moreover, we incorporated a feature selection algorithm to simplify the analog front-end. A machine

  4. Variable Gain Amplifier with Low Power Analog Front End%应用于低功耗模拟前端的可变增益放大器

    Institute of Scientific and Technical Information of China (English)

    张艳; 韩敏

    2016-01-01

    In order to achieve low power gain control of analog front end circuit,a variable gain amplifier(VGA)is proposed based on the duty-cycle of a control signal and the ultra-regeneration,it can realize the precise control of the gain. Different from the traditional majority of variable gain amplifiers,the proposed VGA circuit is not used in digital control and the interface between the amplifier and the DC/AC converter. VGA integrated circuit implement⁃ed using 0.18μm CMOS technology to design the adm is to achieve low power consumption. Both simulation and test results show that the maximum gain of the amplifier in the linear range of 900 mV is 45 dB,the total harmonic distortion is 0.5%,and the power consumption is 6.4μW. Compared to the conventional variable gain amplifier,the variable gain amplifier exhibits a greater gain range and lower power consumption.%为实现模拟前端电路的低功耗增益控制,提出了一种基于控制信号频宽比的可变增益放大器VGA(Variable Gain Amplifier),该电路以超再生为基础,能够对增益实施精细控制。与传统的大多数可变增益放大器不同的是,提出的VGA电路在数字控制和放大器之间的接口并没有使用任何的直流/交流转换器。最终实现的VGA集成电路使用了0.18 mm CMOS技术进行设计,旨在实现低功率消耗。仿真和测试结果均表明,本文提出的放大器在900 mV的线性范围内最大增益为45 dB,总谐波失真为0.5%,功耗为6.4,相比传统的可变增益放大器,表现出更大的增益范围和较低的功耗。

  5. 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

  6. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker;

    2014-01-01

    Due to increased computational power reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between an HRTF enhanced audio system (3D...... with white dots. The results indicate that 3D audio yields faster search latencies than panning audio, especially with larger amounts of distractors. The applications of this research could fit virtual environments such as video games or virtual simulations....

  7. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker;

    2014-01-01

    Due to increased computational power, reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between a HRTF enhanced audio system (3D......) and an amplitude panning audio system (panning) in a virtual environment. We present a performance study involving 33 participants locating aurally-aided visual targets placed at fixed positions, under different audio conditions. A varying amount of visual distractors were present, represented as black circles...

  8. Differences in Human Audio Localization Performance between a HRTF- and a non-HRTF Audio System

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker

    2013-01-01

    -related transfer function (HRTF) system implemen- tation in a study in relation to precision, speed and navi- gational performance in localizing audio sources in a virtual environment. We found that a system using HRTFs is signif- icantly better at all three performance tasks than a system using panning.......Spatial audio solutions have been around for a long time in real-time applications, but yielding spatial cues that more closely simulate real life accuracy has been a computational issue, and has often been solved by hardware solutions. This has long been a restriction, but now with more powerful...... computers this is becoming a lesser and lesser concern and software solutions are now applicable. Most current virtual environment applications do not take advantage of these im- plementations of accurate spatial cues, however. This paper compares a common implementation of spatial audio and a head...

  9. Parametric Coding of Stereo Audio

    Directory of Open Access Journals (Sweden)

    Erik Schuijers

    2005-06-01

    Full Text Available Parametric-stereo coding is a technique to efficiently code a stereo audio signal as a monaural signal plus a small amount of parametric overhead to describe the stereo image. The stereo properties are analyzed, encoded, and reinstated in a decoder according to spatial psychoacoustical principles. The monaural signal can be encoded using any (conventional audio coder. Experiments show that the parameterized description of spatial properties enables a highly efficient, high-quality stereo audio representation.

  10. Portable Audio Design

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh

    2014-01-01

    within online and physical institutional contexts. The approach focuses especially on the relationship to specific sites, and how an awareness of the relationship between the site and the production can be part of the design process. Such awareness entails several approaches: the necessity of paying...... attention to the specific genre; a grasping of the complex relationship between site and time, the actual and the virtual; and getting aquatint with the specific site’s soundscape by approaching it both intuitively and systematically. These steps will finally lead to an audio production that not only...

  11. Hybrid mid-infrared optical parametric chirped-pulse amplification system with a broadband non-collinear quasi-phase-matched power amplifier

    CERN Document Server

    Mayer, Benedikt W; Gallmann, Lukas; Keller, Ursula

    2014-01-01

    We report a hybrid OPCPA system with the capability of generating broadband mid-infrared idler pulses from a non-collinear quasi-phase-matched power amplifier on the basis of periodically poled MgO:LiNbO3. It is seeded by the idler generated from a two-stage collinear pre-amplifier based on aperiodically poled MgO:LiNbO3. The amplification and pulse compression scheme we use does not require any angular dispersion to be introduced or compensated for on either the seed or the generated idler pulses. The mid-IR idler output has a bandwidth of 800 nm centered at 3.4 $\\mu$m. After compression, we obtain a pulse duration of 43.1 fs (FWHM; 41.4-fs transform limit) and a pulse energy of 17.2 $\\mu$J at a repetition rate of 50 kHz.

  12. Design of auxiliary power amplifier based on predistortion technology%基于预失真技术的功率放大器设计

    Institute of Scientific and Technical Information of China (English)

    窦建华; 陈浩

    2012-01-01

    文章基于预失真技术设计了用于广播调频发射的功率放大器,要求工作频率在88-108MHz,功率增益大于25dB,三阶交调小于-45dBc。功率放大器选择Freecale公司的增强型LDMOS功率场效应管MRF6VP2600H。预失真器采用的是二次混频原理,具有结构简单,易于实现,对功放增益影响小等优点。经过ADS仿真软件仿真,基于预失真技术设计的功率放大器达到系统设计要求。%the paper aims to introduce a kind of auxiliary power amplifier which is design for launching the FM radio.It's base on the predistortion technology and it's work in 88-108MHz, power gain is greater than 25dB, and third-order intermodulation is less than -50dBc.the freecale's enhanced LDMOS power mosfet module MRF6VP2600H was selected as the main amplifier.The predistortion device is used the second frequency mixing principle, the structure is simple and easy to realize. After ADS simulation software simulation, based on the design of the predistonion technology power amplifier achieve system design requirements

  13. Optoisolators simplify amplifier design

    Science.gov (United States)

    Ting, Joseph Wee

    2007-09-01

    Simplicity and low parts count are key virtues to this high voltage amplifier. Optoisolators replace complex high voltage transistor biasing schemes. This amplifier employs only 2 optoisolators, 16 high voltage mosfets transistors, 2 low voltage ones, 6 linear IC's and a score of passive components. Yet it can amplify opamp signals to 5 kV peak-to-peak from DC to sine waves up to 20 kHz. Resistor feedback guarantees the fidelity of the signal. It can source and sink 10 mA of output current. This amplifier was conceived to power ion traps for biological whole cell mass measurements. It is a versatile tool for a variety of applications.

  14. 100 kW peak power picosecond thulium-doped fiber amplifier system seeded by a gain-switched diode laser at 2 μm.

    Science.gov (United States)

    Heidt, A M; Li, Z; Sahu, J; Shardlow, P C; Becker, M; Rothhardt, M; Ibsen, M; Phelan, R; Kelly, B; Alam, S U; Richardson, D J

    2013-05-15

    We report on the generation of picosecond pulses at 2 μm directly from a gain-switched discrete-mode diode laser and their amplification in a multistage thulium-doped fiber amplifier chain. The system is capable of operating at repetition rates in the range of 2 MHz-1.5 GHz without change of configuration, delivering high-quality 33 ps pulses with up to 3.5 μJ energy and 100 kW peak power, as well as up to 18 W of average power. These results represent a major technological advance and a 1 order of magnitude increase in peak power and pulse energy compared to existing picosecond sources at 2 μm.

  15. A Novel Ku-Band/Ka-Band and Ka-Band/E-Band Multimode Waveguide Couplers for Power Measurement of Traveling-Wave Tube Amplifier Harmonic Frequencies

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.

    2015-01-01

    This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler, fabricated from two dissimilar frequency band waveguides, is capable of isolating power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT) amplifier. Test results from proof-of-concept demonstrations are presented for a Ku-band/Ka-band MDC and a Ka-band/E-band MDC. In addition to power measurements at harmonic frequencies, a potential application of the MDC is in the design of a satellite borne beacon source for atmospheric propagation studies at millimeter-wave (mm-wave) frequencies (Ka-band and E-band).

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

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard;

    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 known...

  17. Investigation of switching frequency variations in self-oscillating class D amplifiers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Pfaffinger, Gerhard;

    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 class D amplifiers is known as self-oscillation. An parameter of key interest in self-oscillating class D amplifiers is the switching...

  18. Audio Watermarking with Error Correction

    Directory of Open Access Journals (Sweden)

    Aman Chadha

    2011-09-01

    Full Text Available In recent times, communication through the internet has tremendously facilitated the distribution of multimedia data. Although this is indubitably a boon, one of its repercussions is that it has also given impetus to the notorious issue of online music piracy. Unethical attempts can also be made to deliberately alter such copyrighted data and thus, misuse it. Copyright violation by means of unauthorized distribution, as well as unauthorized tampering of copyrighted audio data is an important technological and research issue. Audio watermarking has been proposed as a solution to tackle this issue. The main purpose of audio watermarking is to protect against possible threats to the audio data and in case of copyright violation or unauthorized tampering, authenticity of such data can be disputed by virtue of audio watermarking.

  19. Audio Watermarking with Error Correction

    CERN Document Server

    Chadha, Aman; Goel, Rishabh; Dave, Hiren; Roja, M Mani

    2011-01-01

    In recent times, communication through the internet has tremendously facilitated the distribution of multimedia data. Although this is indubitably a boon, one of its repercussions is that it has also given impetus to the notorious issue of online music piracy. Unethical attempts can also be made to deliberately alter such copyrighted data and thus, misuse it. Copyright violation by means of unauthorized distribution, as well as unauthorized tampering of copyrighted audio data is an important technological and research issue. Audio watermarking has been proposed as a solution to tackle this issue. The main purpose of audio watermarking is to protect against possible threats to the audio data and in case of copyright violation or unauthorized tampering, authenticity of such data can be disputed by virtue of audio watermarking.

  20. Fourier plane image amplifier

    Science.gov (United States)

    Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

    1995-12-12

    A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

  1. Fourier plane image amplifier

    Science.gov (United States)

    Hackel, Lloyd A.; Hermann, Mark R.; Dane, C. Brent; Tiszauer, Detlev H.

    1995-01-01

    A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

  2. 功率放大器及预失真器模型的设计%Designs of Power Amplifier and Predistorter Models

    Institute of Scientific and Technical Information of China (English)

    王伟; 曹民; 朱娟娟; 王戈; 李龙

    2014-01-01

    Traditional polynomial model is commonly used in the design of power amplifier and predistorter models. However, with the gradual increase of orders,the conventional polynomial model exhibits certain numerical instability. This paper gives a novel set of orthogonal polynomials for power amplifier as well as predistorter modeling. In theory, the conventional and orthogonal polynomial models are equivalent and, thus, should behave similarly, but the experiment indicates that these two approaches process data in quite different ways within the finite precision range. The simulation with MATLAB shows that the orthogonal polynomial can reduce the numerical instability, establish high-precision power-amplifier and predistorter models and further improve linearization indexes.%传统多项式常用在功率放大器模型和预失真器模型的设计里。然而,随着多项式阶数逐次增加时,传统多项式模型表现出数据的不稳定性。详细介绍了一种用于功率放大器以及预失真器模型的正交多项式。从理论上讲,传统多项式与正交多项式模型是等效的,但实践表明,在有限精度范围内,这两种方法对数据进行了不同的处理。 MATLAB仿真结果表明,正交多项式可以减轻数值不稳定的问题,建立高精度的功率放大器和预失真器模型,进而改善系统的线性化指标。

  3. Demonstration of Multi-Gbps Data Rates at Ka-Band Using Software-Defined Modem and Broadband High Power Amplifier for Space Communications

    Science.gov (United States)

    Simons, Rainee N.; Wintucky, Edwin G.; Landon, David G.; Sun, Jun Y.; Winn, James S.; Laraway, Stephen; McIntire, William K.; Metz, John L.; Smith, Francis J.

    2011-01-01

    The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz, output power of 200 W and efficiency greater than 60 percent. The modem and the TWTA together enabled an unprecedented data rate at 20 Gbps with low BER of 10(exp -9). The presented results include a plot of the received waveform constellation, BER vs. E(sub b)/N(sub 0) and implementation loss for each of the modulation types tested. The above results when included in an RF link budget analysis show that NASA s payload data rate can be increased by at least an order of magnitude (greater than 10X) over current state-of-practice, limited only by the spacecraft EIRP, ground receiver G/T, range, and available spectrum or bandwidth.

  4. Design of a Front– End Amplifier for the Maximum Power Delivery and Required Noise by HBMO with Support Vector Microstrip Model

    Directory of Open Access Journals (Sweden)

    F. Guneş

    2014-04-01

    Full Text Available Honey Bee Mating Optimization (HBMO is a recent swarm-based optimization algorithm to solve highly nonlinear problems, whose based approach combines the powers of simulated annealing, genetic algorithms, and an effective local search heuristic to search for the best possible solution to the problem under investigation within a reasonable computing time. In this work, the HBMO- based design is carried out for a front-end amplifier subject to be a subunit of a radar system in conjunction with a cost effective 3-D SONNET-based Support Vector Regression Machine (SVRM microstrip model. All the matching microstrip widths, lengths are obtained on a chosen substrate to satisfy the maximum power delivery and the required noise over the required bandwidth of a selected transistor. The proposed HBMO- based design is applied to the design of a typical ultra-wide-band low noise amplifier with NE3512S02 on a substrate of Rogers 4350 for the maximum output power and the noise figure F(f=1dB within the 5-12 GHz using the T- type of microstrip matching circuits. Furthermore, the effectiveness and efficiency of the proposed HBMO based design are manifested by comparing it with the Genetic Algorithm (GA, Particle Swarm Optimization (PSO and the simple HBMO based designs.

  5. A 115dB-DR Audio DAC with –61dBFS out-of-band noise

    OpenAIRE

    Westerveld, Hugo; Schinkel, Daniël; Tuijl, van, B.A.J.

    2015-01-01

    Out-of-band noise (OBN) is troublesome in analog circuits that process the output of a noise-shaping audio DAC. It causes slewing in amplifiers and aliasing in sampling circuits like ADCs and class-D amplifiers. Nonlinearity in these circuits also causes cross-modulation of the OBN into the audio band. These mechanisms lead to a higher noise level and more distortion in the audio band. OBN also leads to interference in the LF and MF band, compromising e.g. AM radio reception. To avoid these p...

  6. 1-MW peak power, 574-kHz repetition rate picosecond pulses at 515 nm from a frequency-doubled fiber amplifier

    Science.gov (United States)

    Zou, Feng; Wang, Ziwei; Wang, Zhaokun; Bai, Yang; Li, Qiurui; Zhou, Jun

    2016-11-01

    1-MW peak power picosecond, 574-kHz repetition rate green laser at 515-nm is generated from a frequency-doubled fiber amplifier. 12-ps pulses with 13.9-μJ energy at 515 nm are achieved with a noncritically phase-matched lithium triborate (LBO) crystal through second harmonic generation of a 1030 nm infrared source. The infrared source employs ultra-large-mode-area rod-type photonic crystal fiber (Rod-PCF) for direct picosecond amplification and delivers 20-W 11.6-ps 2.97-MW pulse train with near-diffraction-limited beam quality (M2 = 1.01).

  7. 5-W Microwave Integrated Circuits (MIC) Gallium Nitride (GaN) Class F Power Amplifier Operating at 2.8 GHz

    Science.gov (United States)

    2010-09-01

    List of Symbols, Abbreviations, and Acronyms 15  Distribition List 16 iv List of Figures Figure 1. I-V characteristics GaN HEMT packaged device...characteristics GaN HEMT packaged device: (a) Cree large-signal model and (b) measured data (Vgs values of –2.8 V to 0.1 V in steps of 0.1 V). S...Two-Stage Quasi-Class-E Power Amplifier in GaN HEMT Technology. IEEE Microwave And Wireless Components Letters 2006, 16, 28–30. 4. Wu, D. Y

  8. Wind velocity measurement accuracy with highly stable 12 mJ/pulse high repetition rate CO2 laser master oscillator power amplifier

    Science.gov (United States)

    Bilbro, James W.; Johnson, Steven C.; Rothermel, Jeffry

    1987-01-01

    A coherent CO2 lidar operating in a master oscillator power amplifier configuration (MOPA) is described for both ground-based and airborne operation. Representative data taken from measurements against stationary targets in both the ground-based and airborne configurations are shown for the evaluation of the frequency stability of the system. Examples of data are also given which show the results of anomalous system operation. Overall results demonstrate that velocity measurements can be performed consistently to an accuracy of + or - 0.5 m/s and in some cases + or - 0.1 m/s.

  9. HASEonGPU-An adaptive, load-balanced MPI/GPU-code for calculating the amplified spontaneous emission in high power laser media

    Science.gov (United States)

    Eckert, C. H. J.; Zenker, E.; Bussmann, M.; Albach, D.

    2016-10-01

    We present an adaptive Monte Carlo algorithm for computing the amplified spontaneous emission (ASE) flux in laser gain media pumped by pulsed lasers. With the design of high power lasers in mind, which require large size gain media, we have developed the open source code HASEonGPU that is capable of utilizing multiple graphic processing units (GPUs). With HASEonGPU, time to solution is reduced to minutes on a medium size GPU cluster of 64 NVIDIA Tesla K20m GPUs and excellent speedup is achieved when scaling to multiple GPUs. Comparison of simulation results to measurements of ASE in Y b 3 + : Y AG ceramics show perfect agreement.

  10. Towards coherent combining of X-band high power microwaves: phase-locked long pulse radiations by a relativistic triaxial klystron amplifier

    Science.gov (United States)

    Ju, Jinchuan; Zhang, Jun; Qi, Zumin; Yang, Jianhua; Shu, Ting; Zhang, Jiande; Zhong, Huihuang

    2016-08-01

    The radio-frequency breakdown due to ultrahigh electric field strength essentially limits power handling capability of an individual high power microwave (HPM) generator, and this issue becomes more challenging for high frequency bands. Coherent power combining therefore provides an alternative approach to achieve an equivalent peak power of the order of ∼100 GW, which consequently provides opportunities to explore microwave related physics at extremes. The triaxial klystron amplifier (TKA) is a promising candidate for coherent power combing in high frequency bands owing to its intrinsic merit of high power capacity, nevertheless phase-locked long pulse radiation from TKA has not yet been obtained experimentally as the coaxial structure of TKA can easily lead to self-excitation of parasitic modes. In this paper, we present investigations into an X-band TKA capable of producing 1.1 GW HPMs with pulse duration of about 103 ns at the frequency of 9.375 GHz in experiment. Furthermore, the shot-to-shot fluctuation standard deviation of the phase shifts between the input and output microwaves is demonstrated to be less than 10°. The reported achievements open up prospects for accomplishing coherent power combining of X-band HPMs in the near future, and might also excite new development interests concerning high frequency TKAs.

  11. A 10 dBm-25 dBm, 0.363 mm2 Two Stage 130 nm RF CMOS Power Amplifier

    Directory of Open Access Journals (Sweden)

    Shridhar R. Sahu

    2013-10-01

    Full Text Available This paper proposes a 2.4 GHz RF CMOS Power amplifier and variation in its main performance parameters i.e, output power, S-parameters and power added efficiency with respect to change in supply voltage and size of the power stage transistor. The supply voltage was varied form 1 V to 5 V and the range of output power at 1dB compression point was found to be from 10.684 dBm to 25.08 dBm respectively. The range of PAE is 16.65 % to 48.46 %. The width of the power stage transistor was varied from 150 µm to 500 µm to achieve output power of range 15.47 dBm to 20.338 dBm. The range of PAE obtained here is 29.085 % to 45.439 %. The total dimension of the layout comes out to be 0.714 * 0.508 mm2 .

  12. Digital Audio Collections

    Directory of Open Access Journals (Sweden)

    Jason Tenter

    2010-11-01

    Full Text Available

    This paper is about the possibility of libraries creating digital music or audio collections based on the current state of the digital music industry, and in comparison with the difficulties librarians have found in adding e-books to collections. In comparing the e-book and digital music markets, factors such as digital rights management (DRM and the differences in both markets’ relationships with customers are examined. This juxtaposition suggests that where e-books have been difficult to include in library collections because publishers want to maintain control over their content, music publishers have had to resign some of the control over their products because of file-sharing, and so may work with libraries to develop these collections in a more constructive way than e-book venders. At the end of the paper, some models are suggested for developing these collections.

  13. Musical examination to bridge audio data and sheet music

    Science.gov (United States)

    Pan, Xunyu; Cross, Timothy J.; Xiao, Liangliang; Hei, Xiali

    2015-03-01

    useful for teaching music lessons on the web. The developed system is evaluated with songs played with guitar, keyboard, violin, and other popular musical instruments (primarily electronic or stringed instruments). The Musicians Aid system is successful at both representing and analyzing audio data and it is also powerful in assisting individuals interested in learning and understanding music.

  14. 单片集成微波/射频功率放大器技术进展%Progress in Monolithic Integrated Microwave/RF Power Amplifier

    Institute of Scientific and Technical Information of China (English)

    李强; 严利人; 周卫; 张伟

    2011-01-01

    As wireless communication market increases, monolithic integrated microwave/RF power amplifier (MMIC PA) plays a more and more important role in 3G and/or 4G systems. Traditional circuits used in mono-stage amplifiers are reviewed, together with their pros and cons. Architectures, such as the Doherty circuitry, EER (Envelope Elimination and Restoration) technology, LINC, etc. , are also discussed. Generally, these technologies may be used to improve linearity and efficiency of microwave power amplifier. Currently, some system-level linearization techniques have also been utilized. The overview may serve as a useful groundwork for those who are designing MMIC Pas.%回顾了一些用于微波单级功率放大器的传统技术方案,讨论了各自的优缺点.从电路模块的角度,总结了若干兼顾功放线性度和效率指标的典型电路拓扑形式,包括Doherty电路、包络消除与恢复(EER)技术、LINC技术等,并总结了当前主要采用的基于电路系统层面的微波射频功放线性化方案.在此基础上,列举评点了文献中一些典型功放的电路特点和性能指标,可为设计和制造人员提供有益参考.

  15. A low-power front-end amplifier for the microstrip sensors of the PANDA microvertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Di Pietro, Valentino; Brinkmann, Kai-Thomas; Riccardi, Alberto [II. Physikalisches Institut, JLU Giessen, Giessen (Germany); Rivetti, Angelo; Rolo, Manuel; Garbolino, Sara [INFN Sezione di Torino, Torino (Italy); Collaboration: PANDA-Collaboration

    2014-07-01

    The most common readout systems designed for nuclear physics detectors are based on amplitude measurements. The information that needs to be preserved is the charge delivered by a particle hitting the sensor. The electronic chain employed in these cases is made of two main building blocks: front-end amplifier and ADC. An issue in the implementation of such an architecture in scaled CMOS technologies is the dynamic range, because the charge information is extrapolated through the sampling of the peak of the front-end output signal. It is therefore interesting to explore the use of time-based architectures that offer better performances. In fact, in these topologies the linearity between the charge and the signal duration can be maintained even if some building blocks in the chain saturate. The main drawback is the loss in resolution since a duration measurement involves the difference between two time measurements. This work presents the design of a front-end optimized for fast Time-over-Threshold applications. The circuit has been developed for the microstrip detectors of the PANDA experiment. The architecture of the front-end amplifier is presented, and simulations in a 110 nm CMOS technology are discussed.

  16. Ways to suppress click and pop for class D amplifiers

    Institute of Scientific and Technical Information of China (English)

    Wang Haishi; Zhang Bo; Sun Jiang

    2012-01-01

    Undesirable audio click and pop may be generated in a speaker or headphone.Compared to linear (class A/B/AB) amplifiers,class D amplifiers that comprise of an input stage and a modulation stage are more prone to producing click and pop.This article analyzes sources that generate click and pop in class D amplifiers,and corresponding ways to suppress them.For a class D amplifier with a single-ended input,click and pop is likely to be due to two factors.One is from a voltage difference (VDIF) between the voltage of an input capacitance (VCIN)and a reference voltage (VREF) of the input stage,and the other one is from the non-linear switching during the setting up of the bias and feedback voltages/currents (BFVC) of the modulation stage.In this article,a fast charging loop is introduced into the input stage to charge VCIN to roughly near VREF.Then a correction loop further charges or discharges VCIN,substantially equalizing it with VREF.Dummy switches are introduced into the modulation stage to provide switching signals for setting up BFVC,and the power switches are disabled until the BFVC are set up successfully.A two channel single-ended class D amplifier with the above features is fabricated with 0.5 μm Bi-CMOS process.Road test and fast Fourier transform analysis indicate that there is no noticeable click and pop.

  17. All-fiber high-average power nanosecond-pulsed master-oscillator power amplifier at 2  μm with mJ-level pulse energy.

    Science.gov (United States)

    Wang, Xiong; Jin, Xiaoxi; Zhou, Pu; Wang, Xiaolin; Xiao, Hu; Liu, Zejin

    2016-03-10

    We present a high-power nanosecond-pulsed Tm-doped fiber amplifier at 1.971 μm based on a master-oscillator power amplifier (MOPA) configuration. When the repetition rate is 500 kHz and the pulse width is 63.3 ns, the average power reaches 238 W, the peak power reaches 7.06 kW, and the pulse energy is 0.477 mJ. When the pulse train's repetition rate is 300 kHz with a pulse width of 63.7 ns, the average power reaches 197 W, the peak power reaches 9.73 kW, and the pulse energy is 0.66 mJ. When the pulse train's repetition rate is 200 kHz with a pulse width of 58.2 ns, the average power reaches 150 W, the peak power reaches 12.1 kW, and the pulse energy is 0.749 mJ. The spectral linewidths of the pulse trains are 0.15, 0.14, and 0.10 nm for 500 kHz repetition rate, 300 kHz repetition rate, and 200 kHz repetition rate, respectively. To the best of our knowledge, this is the first demonstration of high-power nanosecond-pulsed MOPA at 2 μm with the maximum average power reaching 238 W, the maximum peak power reaching 12.1 kW, and the maximum pulse energy reaching 0.749 mJ.

  18. Utilization of non-linear converters for audio amplification

    DEFF Research Database (Denmark)

    Iversen, Niels Elkjær; Birch, Thomas; Knott, Arnold

    2012-01-01

    Class D amplifiers fits the automotive demands quite well. The traditional buck-based amplifier has reduced both the cost and size of amplifiers. However the buck topology is not without its limitations. The maximum peak AC output voltage produced by the power stage is only equal the supply volta...

  19. Digital Audio Watermarking: An Overview

    Directory of Open Access Journals (Sweden)

    Bhuvnesh Kumar Singh

    2013-10-01

    Full Text Available Digital watermarking is a very recent research area. Digital audio watermarking is a method to embed or hide the Watermark (Information signal into a digital signal i.e. Image, audio, text or video data. The watermark is difficult to remove from the audio signal. If the signal is copied, the information or watermark is also carried in the copy. A signal may carry several different watermarks at the same time. It is used to protecting multimedia data from unauthorized copying, piracy, ownership, inventions, authentication etc. in this paper we present the watermarking methods and applications

  20. 新的射频功放预失真线性化方法%New Predistortion Method for RF Power Amplifier Linearization

    Institute of Scientific and Technical Information of China (English)

    詹鹏; 秦开宇; 蔡顺燕

    2011-01-01

    This paper proves that the sequence of two memoryless nonlinear systems, predistorter and RF power amplifier, is commutative through theoretical derivation. For the disadvantages of frequently used predistortion structures, this paper proposes a new predistortion structure combining direct learning structure with indirect learning structure, which is simple and easy to implement The RF power amplifier predistortion linearization method is extended to the situation with memory effect Simulation results show the correctness of this predistortion linearization method. Its linearization performance is better than that using the direct inverse indirect learning structure.%理论推导证明了预失真器和射频功放两个无记忆的非线性系统的顺序可交换,针对常用的预失真学习结构的不足,提出了将直接型和间接型相结合的新预失真学习结构,该方法简单且易实现,并将该射频功放预失真线性化方法推广到了有记忆效应的情况.仿真结果表明,所提出的预失真线性化方法可行,其线性化性能优于采用直接逆间接学习结构的情况.

  1. The Design and Thermal Reliability Analysis of a High-Efficiency K-Band MMIC Medium-Power Amplifier with Multiharmonic Matching

    Directory of Open Access Journals (Sweden)

    Y. Shang

    2016-01-01

    Full Text Available A new high-efficiency K-band MMIC medium-power amplifier (PA is designed with multiharmonic matching using GaAs pHEMT process technology. It has an operation frequency centered at 26 GHz with a bandwidth of 2 GHz. A 20 dBm 1 dB-compression-point output power and 40% efficiency are achieved. A novel thermal reliability analysis method based on ICEPAK is proposed also to evaluate its thermal characteristic. The test result by using a QFI InfraScope™ infrared imaging system is compared with the simulation result. It agrees well with an accuracy within ±1°C differences, which reflects the advantages of the thermal analysis method with respect to accuracy and convenience for use.

  2. The energy scaling in a side-pumped ultra-low-magnification unstable resonator by employing a compact master oscillator power amplifier

    Science.gov (United States)

    Cho, C. Y.; Huang, Y. P.; Su, K. W.

    2016-10-01

    The energy scaling for a diode-side-pumped passively Q-switched Nd:YAG laser in an ultra-low-magnification unstable convex-concave resonator is investigated. Theoretical analysis and experimental results indicate the fact that the energy scaling is restricted by the increasing of side-pumping sources inside the resonator because of the significant pump-to-mode size mismatching. It is verified that employing the master oscillation power amplifier can effectively enlarge the output pulse energy and improve the beam quality. Up to 60-mJ pulse energy with 17-MW peak power is obtained at a pump energy of 520 mJ. A 1573-nm eye-safe laser emission with pulse energy up to 25 mJ is further attended via the extracavity optical parametric oscillator.

  3. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk;

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  4. Modeling Audio Fingerprints: Structure, Distortion, Capacity

    NARCIS (Netherlands)

    Doets, P.J.O.

    2010-01-01

    An audio fingerprint is a compact low-level representation of a multimedia signal. An audio fingerprint can be used to identify audio files or fragments in a reliable way. The use of audio fingerprints for identification consists of two phases. In the enrollment phase known content is fingerprinted,

  5. Tag Based Audio Search Engine

    Directory of Open Access Journals (Sweden)

    Parameswaran Vellachu

    2012-03-01

    Full Text Available The volume of the music database is increasing day by day. Getting the required song as per the choice of the listener is a big challenge. Hence, it is really hard to manage this huge quantity, in terms of searching, filtering, through the music database. It is surprising to see that the audio and music industry still rely on very simplistic metadata to describe music files. However, while searching audio resource, an efficient "Tag Based Audio Search Engine" is necessary. The current research focuses on two aspects of the musical databases 1. Tag Based Semantic Annotation Generation using the tag based approach.2. An audio search engine, using which the user can retrieve the songs based on the users choice. The proposed method can be used to annotation and retrieve songs based on musical instruments used , mood of the song, theme of the song, singer, music director, artist, film director, instrument, genre or style and so on.

  6. A centralized audio presentation manager

    Energy Technology Data Exchange (ETDEWEB)

    Papp, A.L. III; Blattner, M.M.

    1994-05-16

    The centralized audio presentation manager addresses the problems which occur when multiple programs running simultaneously attempt to use the audio output of a computer system. Time dependence of sound means that certain auditory messages must be scheduled simultaneously, which can lead to perceptual problems due to psychoacoustic phenomena. Furthermore, the combination of speech and nonspeech audio is examined; each presents its own problems of perceptibility in an acoustic environment composed of multiple auditory streams. The centralized audio presentation manager receives abstract parameterized message requests from the currently running programs, and attempts to create and present a sonic representation in the most perceptible manner through the use of a theoretically and empirically designed rule set.

  7. Introduction to audio analysis a MATLAB approach

    CERN Document Server

    Giannakopoulos, Theodoros

    2014-01-01

    Introduction to Audio Analysis serves as a standalone introduction to audio analysis, providing theoretical background to many state-of-the-art techniques. It covers the essential theory necessary to develop audio engineering applications, but also uses programming techniques, notably MATLAB®, to take a more applied approach to the topic. Basic theory and reproducible experiments are combined to demonstrate theoretical concepts from a practical point of view and provide a solid foundation in the field of audio analysis. Audio feature extraction, audio classification, audio segmentation, au

  8. Tourism research and audio methods

    DEFF Research Database (Denmark)

    Jensen, Martin Trandberg

    2016-01-01

    Audio methods enriches sensuous tourism ethnographies. • The note suggests five research avenues for future auditory scholarship. • Sensuous tourism research has neglected the role of sounds in embodied tourism experiences.......• Audio methods enriches sensuous tourism ethnographies. • The note suggests five research avenues for future auditory scholarship. • Sensuous tourism research has neglected the role of sounds in embodied tourism experiences....

  9. Modeling Audio Fingerprints: Structure, Distortion, Capacity

    OpenAIRE

    Doets, P.J.O.

    2010-01-01

    An audio fingerprint is a compact low-level representation of a multimedia signal. An audio fingerprint can be used to identify audio files or fragments in a reliable way. The use of audio fingerprints for identification consists of two phases. In the enrollment phase known content is fingerprinted, and ingested into a database, together with all relevant metadata. In the identification phase, unknown audio content is fingerprinted, and the fingerprints form the query to the database. The que...

  10. Active Microwave Technologies Using Ultra-High efficiency P-Band and L -Band Power Amplifiers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AlGaN/GaN devices on SiC substrates will be utilized to achieve Power Added Efficiencies (PAE) in excess of 85%. These wide band-gap solid-state semiconductors...

  11. Radiation Hard Multichannel AlN/GaN HEMT for High Efficiency X- and Ka-Band Power Amplifiers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project is directed to the development of low-loss, high power-density Aluminum Nitride (AlN)/Gallium Nitride (GaN) heterostructure based transistors for...

  12. Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High quality GaN epitaxial films are key to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices. In fact,...

  13. Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High quality GaN epitaxial films are one of the keys to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices....

  14. 基于ADS高效率微波功率放大器设计%Design of high effective microwave power amplifier based on ADS software

    Institute of Scientific and Technical Information of China (English)

    胡小军

    2012-01-01

    基于ADS软件,选取合适的静态直流工作点,采用负载牵引法得到LDMOS晶体管BLF7G22L130的输出和输入阻抗特性,并通过设计和优化得到最佳的共轭匹配网络,设计出高效率功率放大器。ADS设计仿真表明该功率放大器在中心频率2 160 MHz处的效率达到70%,稳定性好、增益平坦度小等优点。%Based on ADS software,the high effective and power amplifier can be designed after learning the output and input impedance characteristic of the LDMOS transistor BLF7G22L130 by Load-pulling method under an appropriate static DC point and realizing the best conjugate match network through design and optimizing.ADS simulation indicates that the effectiveness of this kind of amplifier reaches 70% at the center frequency of 2 160 MHz,with the advantages of high stability and low gain flatness.

  15. 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.

  16. Improvement of out-of-band Behaviour in Switch-Mode Amplifiers and Power Supplies by their Modulation Topology

    DEFF Research Database (Denmark)

    Knott, Arnold

    2010-01-01

    problem where four different approaches: • Multi Carrier Modulation (MCM) • Active Electromagnetic Cancellation (AEC) • Current Driven Power Stages (CDP) • Radio Frequency Power Electronics (RF SMPS) Multi Carrier Modulation (chapter 4) is using more than one external carrier and generating multiple PWM...... signals. Those are combined by a logic circuit to one pulse coded information stream. The average of this stream is proportional to the modulated signal, while the spectral peaks of the switching frequencies are half compared to state-of-the art pulse width modulation (PWM). Active Electromagnetic...

  17. A 0.18 {mu}m CMOS dual-band low power low noise amplifier for a global navigation satellite system

    Energy Technology Data Exchange (ETDEWEB)

    Li Bing; Zhuang Yiqi; Li Zhenrong; Jin Gang, E-mail: waxmax@126.com [Key Laboratory of the Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-12-15

    This paper presents a dual-band low noise amplifier for the receiver of a global navigation satellite system. The differences between single band and multi-band design methods are discussed. The relevant parameter analysis and the details of circuit design are presented. The test chip was implemented in a TSMC 0.18 {mu}m 1P4M RF CMOS process. The LNA achieves a gain of 16.8 dB/18.9 dB on 1.27 GHz/1.575 GHz. The measured noise figure is around 1.5-1.7 dB on both bands. The LNA consumes less than 4.3 mA of current from a 1.8 V power supply. The measurement results show consistency with the design. And the LNA can fully satisfy the demands of the GNSS receiver. (semiconductor integrated circuits)

  18. Rectify output of PWM power amplifier transmitted through long cable%PWM型功率放大器长线传输波形整型

    Institute of Scientific and Technical Information of China (English)

    王刚; 柳秋兴; 宋晓明; 柳井莉

    2013-01-01

    为解决PWM功率放大器输出长线传输引发的波形畸变,可能伤及力矩电动机的问题,对实际系统结构进行了理论分析,找出了可能引发波形畸变的原因,并给出了3种解决方法.实际试验结果证实所给方法的有效性.%When transmitted through long cable, the output of PWM power amplifier may be distorted. The distorted wave may damage torque motor. By analyzing system at work, the factors caused distortion are found, and three solutions are presented. Experiment result shows that these solutions are valid.

  19. A Thermal Design of Forced Air Cooling Solid - state Power Amplifier%某固态功放设备的强迫风冷散热设计

    Institute of Scientific and Technical Information of China (English)

    冷献春

    2012-01-01

    通过对某发射机用固态功放的热设计,阐述了在设备强迫风冷热设计中的设计思路,介绍了结合式鳍片散热器在设备热设计中的应用,以及独立式风道的结构形式,并通过热测试验证了设计的合理性.%This paper provides an idea of forced air cooling devices' design through the thermal design for a solid - state power amplifier. The application of separate air duct and bonded fin heat sinks will be brought forth. Thermal test validates the rationality of design.

  20. SEMICONDUCTOR INTEGRATED CIRCUITS A 0.18 μm CMOS dual-band low power low noise amplifier for a global navigation satellite system

    Science.gov (United States)

    Bing, Li; Yiqi, Zhuang; Zhenrong, Li; Gang, Jin

    2010-12-01

    This paper presents a dual-band low noise amplifier for the receiver of a global navigation satellite system. The differences between single band and multi-band design methods are discussed. The relevant parameter analysis and the details of circuit design are presented. The test chip was implemented in a TSMC 0.18 μm 1P4M RF CMOS process. The LNA achieves a gain of 16.8 dB/18.9 dB on 1.27 GHz/1.575 GHz. The measured noise figure is around 1.5-1.7 dB on both bands. The LNA consumes less than 4.3 mA of current from a 1.8 V power supply. The measurement results show consistency with the design. And the LNA can fully satisfy the demands of the GNSS receiver.

  1. A dual-mode highly efficient class-E stimulator controlled by a low-Q class-E power amplifier through duty cycle.

    Science.gov (United States)

    Chiu, Hung-Wei; Lu, Chien-Chi; Chuang, Jia-min; Lin, Wei-Tso; Lin, Chii-Wann; Kao, Ming-Chien; Lin, Mu-Lien

    2013-06-01

    This paper presents the design flow of two high-efficiency class-E amplifiers for the implantable electrical stimulation system. The implantable stimulator is a high-Q class-E driver that delivers a sine-wave pulsed radiofrequency (PRF) stimulation, which was verified to have a superior efficacy in pain relief to a square wave. The proposed duty-cycle-controlled class-E PRF driver designed with a high-Q factor has two operational modes that are able to achieve 100% DC-AC conversion, and involves only one switched series inductor and an unchanged parallel capacitor. The measured output amplitude under low-voltage (LV) mode using a 22% duty cycle was 0.98 V with 91% efficiency, and under high-voltage (HV) mode using a 47% duty cycle was 2.95 V with 92% efficiency. These modes were inductively controlled by a duty-cycle detector, which can detect the duty-cycle modulated signal generated from the external complementary low-Q class-E power amplifier (PA). The design methodology of the low-Q inductive interface for a non-50% duty cycle is presented. The experimental results exhibits that the 1.5-V PA that consumes DC power of 14.21 mW was able to deliver a 2.9-V sine wave to a 500 Ω load. The optimal 60% drain efficiency of the system from the PA to the load was obtained at a 10-mm coupling distance.

  2. 基于MATLAB的C类功率放大器设计%Design of class C power amplifier based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    高磊; 赵婷婷

    2015-01-01

    高频 C 类功率放大器输出网络由 LC 匹配和滤波电路构成,是设计难点之一。其难度在于功率放大器的输出既要实现阻抗匹配又要滤除谐波分量,两者同时实现,使问题复杂化。本文利用MATLAB 绘制其交流等效电路传递函数曲线,依据传递函数在基波和谐波频率点的幅度大小来确定电路的方案和元件参数。提供了一个设计实例并在 Multisim 上仿真验证。仿真结果表明,该方法设计效率高,简单易行。%High frequency class C power amplifier output network consisted of LC matching and filter circuit, it is one of the difficulties in design. The difficulty lies in the output of the power amplifier have to achieve both impedance matching and filter the harmonic, the two together, making the design complex. In this paper, MATLAB is used to draw the transfer function curve of the AC equivalent circuit, and we determined the circuit scheme and component parameters refer to amplitude curve at fundamental and harmonic wave. In the end, we provided a design example and simulation in Multisim for verification. The simulation results show that this design method is of high efficiency, simple and easy.

  3. Study of digital predistortion for Doherty power amplifier%Doherty功放的数字预失真技术研究

    Institute of Scientific and Technical Information of China (English)

    郑晓林; 原玲; 郝禄国

    2011-01-01

    The power amplifier's efficiency and linearity of communication system affect the performance of the whole system and Doherty technology is an effective way to improve efficiency, but its linearity deteriorates while its increasing the efficiency.Digital predistortion is the most promising linearization technology and all sorts of models are put forward in the past few years.Combined the proper order and memory depth of memory polynomial DPD,a hybrid algorithm of LMS and RLS can realize rapid and efficient linearization of Doherty power amplifier.Simulation result demonstrates that the algorithm mentioned has fast convergence and significantly improves the nonlinearity and memory effect of the system.%通信系统中功率放大器(PA)的效率和线性度影响着整个系统的性能,而Doherty技术是提高效率的一种有效方式,但在提高效率的同时,它的线性度也会变差.数字预失真(DPD)是一种最具有前景的线性化技术,近年来各种模型被不断提出.通过在一种合适阶数、记忆深度的记忆多项式DPD中采用新的RLS与LMS混合算法,实现Doherty功放(DPA)快速、高效的线性化.仿真结果表明所提算法能够快速收敛,对系统的非线性和记忆效应有明显改善.

  4. 基于平台验证的功率放大器数字预失真%Digital predistortion of power amplifier based on platform validation

    Institute of Scientific and Technical Information of China (English)

    邱绕谋; 吴晓芳

    2012-01-01

    Recently,many digital pre-distortion algorithms are based on computer simulations, which are not verified by actual power amplifier. So a platform used to validate the algorithm is proposed which is based on R&.S's vertor signal generator and R&-S's signal and specrum analyzer. First, the digital predistortion algorithm used in the paper is described. And then a detail describe of the platform is got. At last a experimental platform is built on this platform. The experimental results show that the ACPR of signal after PA improves more than 10 dB,so that the power amplifier's degree of linearity is enhanced.%目前大部分数字预失真算法的研究都是基于计算机仿真,而没有在实际功率放大器上面验证,基于此用R&S公司的矢量信号源和频谱分析仪搭建了一个通用的功率放大器数字预失真算法验证平台.介绍了所采用的数字预失真算法,给出该测试平台搭建过程,用平台验证数字预失真算法在实际功率放大器上的性能.通过平台测试表明,功率放大器的邻道功率抑制比ACPR改善了10 dB以上,从而有效提高了功率放大器的线性度.

  5. Concept Framework for Audio Information Retrieval: ARF

    Institute of Scientific and Technical Information of China (English)

    LI GuoHui(李国辉); WU DeFeng(武德峰); ZHANG Jun(张军)

    2003-01-01

    The majority of researches on content-based retrieval focused on visual media.However audio is also an important medium and information carrier from the viewpoint of humanauditory perception, so it is needed to retrieve for audio collection. Audio is handled by conven-tional methods as an opaque stream medium, which is not suitable for information retrieval byits content. In fact, audio carries rich aural information with the form of speech, musical, andsound effects, so it could be retrieved based on its aural content, such as acoustic features, musicalmelodies and associated semantics. In this paper, a concept framework (ARF) for content-basedaudio retrieval is proposed from systematic perspectives, which describes audio content model,audio retrieval architecture and audio query schemes. Audio contents are represented by a hier-archical model and a set of formal descriptions from physical to acoustic to semantic level, whichdepict acoustic features, logical structure and semantics of audio and audio objects. The archi-tecture consisting of audio meta-database, populating and accessing modules presents a systemstructure view of audio information retrieval. The query schemes give generalized approaches andmodes concerning how users deliver audio information needs to audio collections. Finally, an audioretrieval example implemented is used to explain and specify the application of the components in the proposed ARF.

  6. 一种高效的功放自适应预失真器设计%Design Method of Efficient Adaptive Predistorter for High Power Amplifier

    Institute of Scientific and Technical Information of China (English)

    庞兴豪; 任国春; 徐以涛; 陈斌; 李宝柱

    2011-01-01

    An efficient adaptive predistorter for HPA is designed to improve the flexibility of adaptive algorithms as well as the convergence rate of adaption, and to overcome the amplifier over-compressing in the process of high power amplifier (HPA) adaptive predistortion, Firstly, the amplitude-amplitude (AM-AM) and amplitude-phase (AM-PM) adaptive predistorter uses a tandem structure.On one side, amplitude predistortion device adopts the indirect adaptive structure to train; on the other side, phase predistortion device is obtained by directly identifying the AM-PM characteristics of the amplifier.It can make the adaptive algorithms more flexible and the convergence rate much faster.Then, the amplitude predistorter based on sinusoid can give attention to efficiency, maximal export power and linearity.Finally, MQAM and two-tone test signal are taken as examples to carry out simulation.Results verify the advantages of the technology.%在对高功率放大器(HPA)进行自适应预失真过程中,为提高自适应算法运用的灵活性和自适应的收敛速率,解决幅度自适应预处理过程中对幅度过度压缩而影响功放输出功率和效率的问题,设计出一种高效的HPA自适应预失真器.该方案中幅度、相位预失真器相级联,对幅度预失真器采用间接自适应结构进行训练;相位预失真器直接对功放幅度-相位(AM-PM)特性进行辨识,然后取反得到,AM-PM特性辨识器同时又是相位预失真器,能够提高HPA自适应预失真过程中自适应算法运用的灵活性和自适应收敛速率;幅度预失真器基于正弦函数系模型,自适应预失真过程可以同时兼顾功放效率、输出功率和线性度3项重要指标.最后以M-QAM和双音信号为例进行仿真测试,验证了该方法的优势.

  7. Performance Analysis of Multiradio Transmitter with Polar or Cartesian Architectures Associated with High Efficiency Switched-Mode Power Amplifiers (invited paper

    Directory of Open Access Journals (Sweden)

    F. Robert

    2010-12-01

    Full Text Available This paper deals with wireless multi-radio transmitter architectures operating in the frequency band of 800 MHz – 6 GHz. As a consequence of the constant evolution in the communication systems, mobile transmitters must be able to operate at different frequency bands and modes according to existing standards specifications. The concept of a unique multiradio architecture is an evolution of the multistandard transceiver characterized by a parallelization of circuits for each standard. Multi-radio concept optimizes surface and power consumption. Transmitter architectures using sampling techniques and baseband ΣΔ or PWM coding of signals before their amplification appear as good candidates for multiradio transmitters for several reasons. They allow using high efficiency power amplifiers such as switched-mode PAs. They are highly flexible and easy to integrate because of their digital nature. But when the transmitter efficiency is considered, many elements have to be taken into account: signal coding efficiency, PA efficiency, RF filter. This paper investigates the interest of these architectures for a multiradio transmitter able to support existing wireless communications standards between 800 MHz and 6 GHz. It evaluates and compares the different possible architectures for WiMAX and LTE standards in terms of signal quality and transmitter power efficiency.

  8. Location audio simplified capturing your audio and your audience

    CERN Document Server

    Miles, Dean

    2014-01-01

    From the basics of using camera, handheld, lavalier, and shotgun microphones to camera calibration and mixer set-ups, Location Audio Simplified unlocks the secrets to clean and clear broadcast quality audio no matter what challenges you face. Author Dean Miles applies his twenty-plus years of experience as a professional location operator to teach the skills, techniques, tips, and secrets needed to produce high-quality production sound on location. Humorous and thoroughly practical, the book covers a wide array of topics, such as:* location selection* field mixing* boo

  9. Investigation on Satellite-borne High-power Solid-state Power Amplifier Technology and Experiment%星载高功率固态功放关键技术与实验研究

    Institute of Scientific and Technical Information of China (English)

    武小坡; 赵海洋; 奚松涛

    2014-01-01

    该文结合某星载集中式固态发射机的高功率固态功率放大器,从星载应用着手,重点从高功率密度热设计、微放电防护设计、电磁兼容性设计等方面介绍了星载高功率固态功放关键性技术的设计方法,并且通过相关的真空环境试验验证了功率放大器组件设计方法的正确性和真空环境适应性。%Based on the research and development efforts of satellite-borne lumped solid-state transmitters, the design of a satellite-borne high-power microwave amplifier module is introduced. Focusing on satellite-borne applications, aspects of the high-power density thermal design, multipactor proof design, EMC design and so on, which are critical technologies for a solid-state power amplifier, are discussed. Subsequently, experiments are used to verify the concept.

  10. Generation of high-energy sub-20 fs pulses tunable in the 250-310 nm region by frequency doubling of a high-power noncollinear optical parametric amplifier.

    Science.gov (United States)

    Beutler, Marcus; Ghotbi, Masood; Noack, Frank; Brida, Daniele; Manzoni, Cristian; Cerullo, Giulio

    2009-03-15

    We report on the generation of powerful sub-20 fs deep UV pulses with 10 microJ level energy and broadly tunable in the 250-310 nm range. These pulses are produced by frequency doubling a high-power noncollinear optical parametric amplifier and compressed by a pair of MgF2 prisms to an almost transform-limited duration. Our results provide a power scaling by an order of magnitude with respect to previous works.

  11. Evaluation of Audio Compression Artifacts

    Directory of Open Access Journals (Sweden)

    M. Herrera Martinez

    2007-01-01

    Full Text Available This paper deals with subjective evaluation of audio-coding systems. From this evaluation, it is found that, depending on the type of signal and the algorithm of the audio-coding system, different types of audible errors arise. These errors are called coding artifacts. Although three kinds of artifacts are perceivable in the auditory domain, the author proposes that in the coding domain there is only one common cause for the appearance of the artifact, inefficient tracking of transient-stochastic signals. For this purpose, state-of-the art audio coding systems use a wide range of signal processing techniques, including application of the wavelet transform, which is described here. 

  12. 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.

  13. Amplificador de audio Clase D

    OpenAIRE

    2012-01-01

    El presente proyecto lleva a cabo el desarrollo de un amplificador de audio tipo D basado en dos tipos de modulación, modulación PWM y modulación Sigma-Delta ambos con puente inversor en H. Tanto el modulador PWM como el modulador Sigma-Delta se desarrollaran mediante circuitos digitales implementados en una FPGA. La señal de audio de entrada se digitalizará mediante un convertidor analógico–digital (ADC) que también estará controlado mediante una circuitería digital implementada en la misma ...

  14. A Joint Audio-Visual Approach to Audio Localization

    DEFF Research Database (Denmark)

    Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2015-01-01

    Localization of audio sources is an important research problem, e.g., to facilitate noise reduction. In the recent years, the problem has been tackled using distributed microphone arrays (DMA). A common approach is to apply direction-of-arrival (DOA) estimation on each array (denoted as nodes...

  15. L频段高效功率放大器设计%Design on an L-band High-efficency Power Amplifier

    Institute of Scientific and Technical Information of China (English)

    刘传洋; 蓝永海

    2014-01-01

    As one of the new kind of semiconductor material,the high power density and breakthrough field capacity of GaN fea-tures high bandwidth and efficiency. According to these features of GaN,the input and output matching circuits of power tube are simu-lated and designed by using ADS simulation software,and then the efficiency index of the amplifier is tested. The experiment results show that the output power of continuous wave can be up to 100 W and the efficiency can be better than 50% in L band,at the same time the high efficiency of the GaN power tube are validated.%氮化镓( Gallium ( iii) Nitride, GaN)作为新一代半导体材料的代表,其高功率密度、高击穿场强的特点使其具备了带宽宽、效率高等优点。根据GaN功率管的特点,采用ADS仿真软件,对功率管进行了直流分析、稳定性分析以及输入输出匹配电路的仿真与设计,并对放大器效率指标进行了测试。实验数据表明,功率放大器在L频段可以达到连续波输出功率100 W,效率大于50%,验证了GaN功率管高效率的特性。

  16. X波段30W固态功率放大模块的设计%Design for 30W X-band Solid State Power Amplifier Module

    Institute of Scientific and Technical Information of China (English)

    程光伟; 闫燕勤

    2014-01-01

    Microwave power amplifier is widely used and indispensable in radar,navigation,communications,satellite earth station,electronic warfare equipment .Introduce a x-band solid-state power amplifier module design process.Through the RF simulation software ADS according to the S parameters of microwave solid state power amplifier module design and optimize bias blocking circuit and matching circuit,power amplifier through synthesis of cascade,power allocation,meet the requirements of design index.%微波功率放大器的应用范围广,在雷达、导航、通信、卫星地面收发站、电子对抗仪器设备中不可或缺。介绍一个 X波段固态功率放大器模块的设计过程,通过 ADS射频仿真软件根据 S参数对微波固态功放模块的偏置隔直电路以及匹配电路进行设计优化,功率放大器经过级联、功率分配合成,达到设计的指标要求。

  17. Super Audio Induction Heating Power in the Application of Aquatic Breeding%超音频感应加热电源在水产养殖中的应用

    Institute of Scientific and Technical Information of China (English)

    李文江; 陈刚; 万卜源; 刘南

    2013-01-01

    According to the traditional aquiculture heat boiler (coal,fuel or electricity) heating devicehas high in energy consumption,low power, pollution serious,and operation cost higher etc shortcomings, a kind of electromagnetic induction based on the principle of super audio induction heating device was put forward. With high speed digital sig-nal processor TMS320F2812DSP as control core,finished design of frequency tracking digital phase lock loop (DPLL), the fuzzy PID control method to real-time dynamic adjustment of temperature,and realized the precise control of the water supply system digital constant temperature. The prototype test show that the device has fast heating speed,high precision,high efficiency,energy saving and environmental protection.%  针对水产养殖传统加温采用锅炉(燃煤、燃油或用电)加热装置能耗高、功率低、污染严重、运行费用高等缺点,设计一款以电磁感应原理为基础的超音频感应加热装置。该装置以高速数字信号处理器TMS320F2812DSP为控制核心,完成了频率跟踪的数字锁相环(DPLL)设计,采用模糊PID控制方法对温度进行实时动态调整,实现了高精度数字化控制的恒温供水系统。样机试验表明,该装置加热速度快,精度高,效率高,节能环保。

  18. Audio watermark a comprehensive foundation using Matlab

    CERN Document Server

    Lin, Yiqing

    2015-01-01

    This book illustrates the commonly used and novel approaches of audio watermarking for copyrights protection. The author examines the theoretical and practical step by step guide to the topic of data hiding in audio signal such as music, speech, broadcast. The book covers new techniques developed by the authors are fully explained and MATLAB programs, for audio watermarking and audio quality assessments and also discusses methods for objectively predicting the perceptual quality of the watermarked audio signals. Explains the theoretical basics of the commonly used audio watermarking techniques Discusses the methods used to objectively and subjectively assess the quality of the audio signals Provides a comprehensive well tested MATLAB programs that can be used efficiently to watermark any audio media

  19. Audio Watermarking Using Lsb With Adjustment Method

    Directory of Open Access Journals (Sweden)

    Ansith.S, Priyanka Udayabhanu

    2013-05-01

    Full Text Available In this paper we are discussing watermarking on audio signals. In this method the recorded audio data is first sampled using a sampling frequency of 22050 Hz. Then the watermark message is watermarked into the sampled data of the audio signal. In this method the adjustment is done to increase the accuracy of the watermarked signal. Finally we extract the message from the audio data.

  20. Engaging Students with Audio Feedback

    Science.gov (United States)

    Cann, Alan

    2014-01-01

    Students express widespread dissatisfaction with academic feedback. Teaching staff perceive a frequent lack of student engagement with written feedback, much of which goes uncollected or unread. Published evidence shows that audio feedback is highly acceptable to students but is underused. This paper explores methods to produce and deliver audio…