A power efficient and simple scheme for dynamically biasing cascode amplifiers and telescopic op-amps

A simple dynamic biasing scheme to extend the input/output range of cascode amplifiers is introduced. It requires minimum extra hardware and no additional power consumption. A dynamic biased telescopic op-amp is discussed as an application example. Experimental results of a fabricated test chip in 0.5 μm CMOS technology are presented that verify the proposed technique.     

远泵放大器大功率泵浦光传输技术的实验研究

介绍了远泵放大器大功率泵浦光传输技术的实验研究,该技术应用在大跨距无中继光纤传输系统中,采用G．652光纤,构成了速率为2．5Gb／s、跨距为507km的大跨距无中继光纤传输系统。     

X波段四路合成氮化镓功率放大器

本文利用自主研制的SiC 衬底的,栅宽为2.5mm的AlGaN/GaN HEMT器件,设计完成了X波段氮化镓合成固态放大器模块。模块由AlGaN/GaN HEMT器件,Wilkinson功率合成/分配器,偏置电路和微带匹配电路构成。为了使放大器稳定,在每一路放大器的输入端和输出端加入了RC 稳定网络,在栅极和直流输入之间加上稳定电阻,并且利用3/4 λ 枝接的威尔金森功率合成/分配器,从而有效消除其自激和低频串扰问题。在连续波条件下(直流偏置电压为Vds=27V,Vgs=-4.0V),放大器在8GHz频率下线性增益为5dB,最大效率为17.9%,输出功率最大可为42.93dBm,此时放大器增益压缩为3dB。四路合成放大器的合成效率是67.5%。通过分析,发现了放大器合成效率的下降是由每路放大器特性的不一致、功率合成网络的损耗以及电路制造误差所造成。     

A new sparse design framework for broadband power amplifier behavioral modeling and digital predistortion

In this paper, we propose a new sparse framework for the design of the behavioral model and digital predistorter of a broadband power amplifier (PA). We start by formulating the Volterra kernel to multidimensional memory polynomial by considering the high‐order dynamic truncation of the Volterra model. Then we show how an estimate of the most significant coefficients may be obtained using a matching pursuit (MPT) algorithm by exploiting the sparsity of the model. After the indices of the nonzero coefficients are roughly estimated, the block exact Householder inverse QR‐decomposition‐based recursive least squares (HIQRD‐RLS) algorithm is utilized to estimate the sparse model complex coefficients. For broadband nonlinear PAs, the proposed approach is demonstrated to achieve the best performance among the well‐known traditional approaches in terms of in‐band and out‐of‐band specifications. The proposed approach is also validated by evaluating the digital predistortion (DPD) performance on a Class‐AB PA in terms of adjacent channel power ratio (ACPR). © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Optical gain in 1.3-μm electrically driven dilute nitride VCSOAs

We report the observation of room-temperature optical gain at 1.3 μm in electrically driven dilute nitride vertical cavity semiconductor optical amplifiers. The gain is calculated with respect to injected power for samples with and without a confinement aperture. At lower injected powers, a gain of almost 10 dB is observed in both samples. At injection powers over 5 nW, the gain is observed to decrease. For nearly all investigated power levels, the sample with confinement aperture gives slightly higher gain.     

Study of silicon photomultipliers fast amplifier and thermoregulation

The silicon photomultipliers (SiPM) are adopted in various physical applications, from medical physics to astrophysics, for their advantages in terms of cost and weight with respect to traditional photo detectors. Their low bias voltage supply (about 30 V), hardiness and resistance to magnetic field are ideal characteristics for space application. In the frame of INFN-Irst collaboration, some of them have been developed and produced at FBK (Trento-Italy), and have been characterized in the INFN laboratories of Bologna (DaSiPM2 collaboration).The SiPM can be used in conjunction with fibres and counters in high energy physics experiments. To exploit the SiPM time resolution, a fast amplifier has been studied. The SiPM gain depends critically on temperature and a thermal stabilization is also necessary. The use of a thermoelectric cooler module based on a Peltier cell has been investigated, and the results are shown.     

Photonic bandgap fibre oscillators and amplifiers

In the search for ever higher output power or energy from fibre oscillators or amplifiers a nowadays mature technology relies on enlarging the fibre mode area. Broadening of the core diameter, all other things being equal, inevitably yields a multimode fibre, thereby dramatically limiting the device usefulness. Various strategies have been deployed to design and manufacture single transverse mode fibre oscillators and amplifiers, among which making use of the so-called photonic bandgap effect to restrict the modal population seems promising. Helped by efficient and reliable numerical tools the design of large mode area singlemode photonic bandgap fibres is presented. Two fibres with 20-μm and 40-μm core diameter, both of them heavily doped with Yb³⁺ ions, have been fabricated by the widespread modified chemical vapour deposition process and are shown to behave properly when used as the core element of either continuous wave oscillators or femtosecond amplifiers. Good output beam quality (M² parameter spanning from 1.12 to 1.5 for the set of fibres studied) and high slope efficiency of 80% in cw oscillation regime are demonstrated. Furthermore the 40-μm core diameter fibre is shown to be resilient to tight bending down to 7.5-cm radius. The stack-and-draw process makes it easy to tailor the outer cladding so that a large numerical aperture can be reached. Subsequently, from this air-clad fibre, 500 fs 47 W pulses at 35 MHz are obtained from a two-stage chirped pulse amplification system.     

拉曼放大器的交迭因子模型及其性能特性仿真

通过引人交迭因子的概念，提出了光纤拉曼放大器(FRA)仿真的改进模型。采用此模型进行仿真，可以在保证精度的基础上，显著缩短仿真时间。在此模型的基础上，仿真了色散和非线性效应对超高斯脉冲抽运拉曼放大器性能的影响。结果表明，色散对其影响较大，而非线性系数对其影响相对较小。     

Wide dynamic range parallel feedback transimpedance amplifier for 10 Gb/s optical links

This paper presents the design and implementation of a new wide dynamic range parallel feedback (PF) transimpedance amplifier (TIA) for 10 Gb/s optical links. The wide dynamic range is attributed to the novel TIA architecture employing both shunt-shunt and shunt-series feedback networks. The outstanding features of the TIA are wide dynamic range, high gain, low power consumption and design simplicity. A prototype implemented in a 0.5 μm SiGe BiCMOS technology and operating at −3.3 V power supply features an 18.4 dBm dynamic range with a BER less than 10⁻¹², an optical sensitivity of −16 dBm, optical overload of +2.4 dBm, a bandwidth of 8.27 GHz, a gain of 950 Ω and a power consumption of 189 mW. The new parallel feedback architecture offers improved overload and noise performance when compared to previously reported, state of the art, single feedback TIA designs and meets all the 10 Gigabit Ethernet and short-reach OC-192 SONET specifications. Ricardo Andres Aroca received the B.S. (Hons) degree in electrical engineering from the University of Windsor, Canada, and the M.S. degree from the University of Toronto, Canada, in 2001 and 2004, respectively. In 2000 he spent two 4 month internships with Nortel Networks in the Microelectronics Department. Mr. Aroca received the Natural Sciences and Engineering Research Counsel of Canada (NSERC) Postgraduate Scholarship award in 2002. He is currently working toward the Ph.D. degree at the University of Toronto where his research interests lie in the area of high-frequency integrated circuits for wireless and wireline communication systems. C. Andre T. Salama received the B.A.Sc. (Hons.) M.A.Sc. and Ph. D. degrees, all in Electrical Engineering, from the University of British Columbia in 1961, 1962 and 1966 respectively. From 1962 to 1963 he served as a Research Assistant at the University of California, Berkeley. From 1966 to 1967 he was employed at Bell Northern Research, Ottawa, as a Member of Scientific Staff working in the area of integrated circuit design. Since 1967 he has been on the staff of the Department of Electrical and Computer Engineering, University of Toronto where he held the J.M. Ham Chair in Microelectronics from 1987 to 1997. In 1992, he was appointed to his present position of University Professor for scholarly achievements and preeminence in the field of microelectronics. In 1989-90, he was awarded the ITAC/NSERC Research Fellowship in information technology. In 1994, he was awarded the Canada Council I.W. Killam Memorial Prize in Engineering for outstanding career contributions to the field of microelectronics. In 2000, he received the IEEE Millenium Medal. In 2003, he received the Outstanding Lifetime Achievement Award from the Canadian Semiconductor Technology Conference for seminal and outstanding contributions to semiconductor device research and promotion of Canadian University research in microelectronics. In 2004, he received the NSERC Lifetime Achievement Award of Research Excellence for outstanding and sustained contributions to the field of microelectronics and the Networks of Centres of Excellence (NCE) Recognition Award for research excellence and outstanding leadership.He was associate editor of the IEEE Transactions on Circuits and Systems in 1986–88 and a member of the International Electron Devices Meeting (IEDM) Technical Program Committeein 1980–82, 1987–89 and 1996–98. He was the chair of the Solid State Devices Subcommittee for IEDM in 1998 and was a member of the editorial board of Solid State Electronics from 1984 to 2002. He is presently a member of the editorial board of the Analog IC and Signal Processing Journal and the Technical Program Committee of the International Symposium on Power Semiconductor Devices and ICs (ISPSD) and the Technical ProgramCommittee of the International Symposium on Low Power Electronics and Design (ISLPED). He chaired the technical program committee of ISPSD in 1996 and was the general chair for the conference in 1999.Dr. Salama is the Scientific Director of Micronet, a network of centres of excellence focussing on microelectronics research and funded by the Canadian Government and Industry. He has published extensively in technical journals, is the holder of eleven patents and has served as a consultant to the semiconductor industry in Canada and the U.S. His research interests include the design and fabrication of semiconductor devices and integrated circuits with emphasis on deep submicron devices as well as circuits and systems for high speed, low power signal processing applications. Dr. Salama is a Fellow of the Institute of Electrical and Electronics Engineers, a Fellow of the Royal Society of Canada, a Fellow of the Canadian Academy of Engineering, a member of the Association of Professional Engineers of Ontario, the Electrochemical Society and the Innovation Management Association of Canada.     

双腔光力学系统的稳态纠缠

为了提高耦合腔光力学系统的稳态纠缠,将光学参量放大器放置到光学腔中并研究了其纠缠状.首先利用量子朗之万方程和线性化处理,求出系统的稳态解; 然后将纠缠负对数作为纠缠判据,对系统的量子纠缠进行数值模拟.研究结果表明,含有光学参量放大器的系统不但可以显著增强稳态力学纠缠,而且可使纠缠不受热库环境温度的影响; 因此,本文方案可为操控力学系统间的量子纠缠提供参考.