百纳秒脉宽单频大能量1064 nm激光器

报道了基于光纤-固体混合放大的百纳秒脉冲宽度单频大能量1064 nm激光光源的研究工作。采用1064 nm分布反馈(DFB)半导体激光器作为单频连续种子光光源,采用声光调制器将种子光整形为脉冲宽度约为149.0 ns的洛伦兹波形脉冲光,重复频率为60 Hz,经过级联的全保偏光纤放大器放大后,获得单脉冲能量约为2.1μJ、脉冲宽度约为216.7 ns的脉冲光输出。固体放大部分采用激光二极管(LD)端面抽运的Nd∶YVO₄晶体作为高增益的前放大器进行双程放大,采用LD单侧面抽运的Nd∶YAG板条晶体作为预放大器进行双程放大,采用两级LD双侧面抽运的Nd∶YAG板条晶体作为功率放大器,最终获得了单脉冲能量为151.4 mJ、脉冲宽度约为267.8 ns的激光输出。采用光学外差法对输出脉冲激光的线宽进行了测试,线宽约为14.2 MHz。研究结果为星载相干测风激光雷达采用1.06μm的激光光源提供了新的技术路线。     

低重复频率脉冲掺镱光纤放大器

为了研究低重复频率两级脉冲掺Yb3+光纤放大器,采用脉冲信号驱动的半导体激光器作为种子光源,产生重频100Hz、半峰全宽100ns、能量30nJ的矩形光脉冲。第1级放大采用单模掺Yb3+光纤放大器,双程放大方案有效地抑制了放大自发辐射,放大后的脉冲能量达到了8.2μJ。第2级放大采用纤芯直径15μm的双包层掺Yb3+光纤放大器,大功率多模半导体激光器连续抽运。结果在抽运功率为7.3W时,放大输出脉冲能量达到了242μJ,放大输出半峰全宽压缩为29ns。输出的光束质量较好,为准单模输出。结果表明,该光纤放大器输出脉冲能量高,具有全光纤化、结构简单的特点。     

一种高增益、大带宽跨阻放大器的设计

作为激光近炸引信中探测与目标识别核心元件的光电探测器,其性能取决于光电二极管和相应的放大电路。针对引信、制导应用对光电探测器的要求,提出一种新型高增益、大带宽跨阻放大器设计。该跨阻放大器由两级放大电路构成,第一级由两个对称的RGC（Regulated Cascode）结构组成,消除光电二极管漏电流对直流工作点影响,隔离光电二极管寄生电容提升工作带宽;第二级放大电路由三个级联的电流复用反相放大器构成,是跨阻放大器的主要增益级;最后以射级跟随器输出,为后续系统提供足够的电压摆幅。 该电路基于SMIC 0.35μm 标准CMOS工艺设计,仿真结果表明：跨阻增益为110.2dBΩ,带宽为46.7MHz,40MHz处的等效输入噪声电流谱密度低至1.09pA/ ,带宽内等效输出噪声电压为5.37mV。测试结果表明,跨阻放大器增益约为109.3 dBΩ,输出电压信号上升时间约为7.8ns,等效输出噪声电压大小为6.03mV,功耗约为10mW,对应芯片面积为1560×810μm2。 关键字：跨阻放大器、高增益、大带宽、RGC、反相放大器     

近地层紫外动态目标探测微弱信号放大器设计

针对紫外探测器输出信号微弱,常规放大电路难以实现对微弱信号放大,为此设计了一种适于近地层紫外动态目标探测的微弱信号放大器。通过分析探测器输出信号特点,提出了微弱信号放大器的指标要求。围绕预定的指标要求设计电荷前置放大电路、整形滤波电路以及增益调整电路,使放大器的输出波形满足总体设计要求。经软件Multisim模拟仿真结果表明,该放大器各项指标均达到设计要求,可以将探测器输出电荷脉冲信号放大整形输出相应准高斯脉冲波形,为后续处理提供可靠的信号,具有一定适用性。     

全光纤结构高增益脉冲光纤放大器的实验研究

为了探讨多级级联掺镱光纤放大器的脉冲放大特性,采用主振功率放大技术(MOPA),实验研究了3级级联、全光纤结构的高增益脉冲激光放大器。通过优化各放大级增益光纤的长度和抽运光功率的大小,在保证高放大增益的同时,抑制了掺镱光纤中自发辐射光的自生激光振荡,并对第2放大级进行了结构优化。在脉冲激光放大过程中实现了中心波长1064nm、脉冲宽度19ns、重复频率5kHz、峰值功率3.8kW、总放大增益达43.8dB的稳定激光输出。同时,制作完成了1台结构紧凑、全光纤结构的脉冲光纤放大器样机,对重复频率1Hz的低频脉冲信号进行了放大实验,也得到了43.2dB的输出信号增益。结果表明,本脉冲光纤放大器对低频脉冲信号有很好的放大效果。     

高效开关型低频功率放大器-LM4665/4667

开关型低频放大器又被称作D类放大器或脉冲放大器,但称为数字放大器属不规范的商业名称,因为D类放大器只是PW M脉冲调制,与数字编码并不相干。D类放大器的实质是利用脉宽调制技术将模拟音频信号变成PW M脉冲,因而采用脉冲放大技术可以实现极高的效果。美国国家半导体公司开发的LM466X系列D类功放集成电路中还采用最新的δ-∑脉冲调制技术,使输出噪音和非线性失真都降到极低水平。同时,还可省去D类放大器输出电路中特有的LC滤波器,使输出端直接接入耳机或扬声器。LM4665和LM4667只是具体参数和封装形式的区别;现以LM4665为例介绍如…     

高辐射通量下CdZnTe探测器的脉冲处理技术研究

针对高辐射通量条件下碲锌镉(CdZnTe)辐射探测器对模拟前端输出信号应具有快速上升时间及窄脉宽的要求,研究了CdZnTe探测器中电荷灵敏前置放大器(CSA)、准高斯脉冲滤波整形放大器的原理。采用Multisim,仿真分析了CSA输出脉冲信号上升时间、衰减时间和滤波整形放大器级联输入电阻、运放反馈电容等优化参数。基于仿核精密脉冲源搭建实验平台,完成了CSA和准高斯滤波整形放大器的实验验证工作。结果表明,CSA的输出信号上升时间为10 ns,下降时间为150 μs,准高斯脉冲脉宽达200 ns。CSA和滤波整形放大电路的输出脉冲波形与仿真结果一致,满足了高分辨率半导体能谱测量系统的要求。     

1kHz全光纤双程结构掺Yb3+脉冲光纤放大器

以1KHz低重复频率的脉冲激光为信号光源,实验研究了全光纤双程结构的脉冲光纤放大器.利用光纤声光调制器(AOM)滤除了放大过程产生的放大自发辐射光(ASE),并测量了该ASE功率;分析了低重复频率及双程结构对放大器输出特性的影响;研究了抽运光功率对输出脉冲宽度和脉冲峰值功率的影响.在注入信号激光波长1060nm、脉冲宽度10.2ns、峰值功率0.58W时,获得放大脉冲激光的脉冲宽度7.9ns、峰值功率245.2W,对应增益26.3dB.     

混合放大100MHz高重复频率窄脉宽单频激光器

利用高速光强度调制器对线宽为70kHz的单频连续(CW)光纤激光器发出的激光进行调制,获得了100MHz高重频、1ns窄脉宽激光输出,调制后脉冲激光的线宽小于0.8GHz。利用光纤激光放大器和Nd…YVO4固体激光放大器的混合放大装置进行放大,在一级固体激光放大后输出平均功率为13 W,在二级固体激光放大后获得了32.9W的脉冲激光输出。实验中对调制后单频窄脉宽的小信号激光采用光纤激光放大器进行预放大,预放大输出激光功率达到2W后采用固体激光放大器放大,从而避免了单频窄脉宽激光在光纤放大器中极易产生的受激散射和放大自发辐射(ASE)所导致的放大器损坏。放大后的激光仍保持了0.8GHz线宽和1ns脉宽、100MHz重频。这样的输出激光在一些特殊要求中可以获得应用。     

高效开关型低频功率放大-LM4665／4667

开关型低频放大器又被称作D类放大器或脉冲放大器，但称为数字放大器属不规范的商业名称，因为D类放大器只是PWM脉冲调制，与数字编码并不相干。D类放大器的实质是利用脉宽调制技术将模拟音频信号变成PWM脉冲，因而采用脉冲放大技术可以实现极高的效果。     

An integrated photodetector-amplifier using a-Si p-i-n photodiodesand poly-Si thin-film transistors

The authors propose a photodetector-amplifier circuit consisting of a bridge photodetector circuit and a CMOS differential amplifier, both monolithically integrated on a transparent substrate. A test circuit was fabricated using a-Si p-i-n photodiodes and poly-Si thin-film transistors on a quartz substrate. A clear effect of the differential amplifier was demonstrated in the test circuit. It is shown that the circuit performance can be controlled by changing the bias current of the differential amplifier. With a relatively low bias current on the order of 10^-11 A, the circuit works digitally with output voltages either close to 0 V or V_DD. The power consumption of the circuit is approximately 60 μW, which is low enough for use in two-dimensional arrays     

L波段1200W固态功率放大器的设计

基于L波段750 W的LDMOS功放管,设计了一种1200 W固态功率放大器,该放大器由功率放大电路、水冷板、稳压电源、控保电路等部分组成,支持连续波和脉冲两种工作方式。通过对放大电路的设计,采用三级级联放大,制作了固态功率源实物样机并进行了测试。测试结果表明,固态功率放大器工作频率为1.3 GHz,带宽为±5 MHz,最大输出功率能够达到1300 W,具有体积小、成本低、输出功率稳定、相噪低、谐波抑制度高等优点,能应用于加速器、微波加热、物联网、移动通信等领域。     

A highly integrated wideband millimeter-wave MMIC converter using0.25-μm P-HEMT technology

A highly integrated wideband converter that was designed to upconvert the entire 6- to 18-GHz input RF frequency band to a 22-GHz intermediate frequency using a 28- to 40-GHz local oscillator (LO) is described. The circuit was designed using 0.25-μm pseudomorphic HEMT technology. The converter incorporates a three-stage RF amplifier, a three-stage LO amplifier, and an active balanced mixer, all integrated on a chip 96 mil×96 mil in size. The upconverter monolithic microwave integrated circuit (MMIC) has an average of 10-dB conversion gain across the full 6-18-GHz input band     

On the performance analysis and design of an integrated front-end PIN/HBT photoreceiver

A detailed study on the performance analysis and optimum design of an integrated front-end PIN/HBT photoreceiver for fiber-optic communication is presented. Receiver circuits with two different transimpedance amplifiers-a single-stage common emitter (CE) amplifier and a three-stage amplifier comprising a CE amplifier and two emitter followers (EFs), are analyzed assuming a standard load of 50 /spl Omega/. A technique to include the transit-time effect of a PIN photodetector on the overall receiver circuit analysis is introduced and discussed. Gain-bandwidth product (GB) and gain-bandwidth-sensitivity measure product (GBS) are obtained as functions of feedback resistance (R/sub F/) and various device parameters. Hence, some optimum designs are suggested using a photodetector of area 100 /spl mu/m/sup 2/ and with a feedback resistance of 500 /spl Omega/. The bandwidth plays a major role in determining the optimum designs for maximum GB and maximum GBS. A bandwidth >8 GHz has been obtained for the photoreceiver even with a single-stage CE amplifier. The optimum design for a receiver with a three-stage amplifier shows a bandwidth of 35 GHz which is suitable for receivers operating well beyond 40 Gb/s; however, in this case, the gain is reduced. The performance of different fixed square-emitter structures are investigated to choose the optimum designs corresponding to different gains. Very low power dissipation has been estimated for the optimized devices. The noise performance of the devices with optimum designs was calculated in terms of the minimum detectable optical power for a fixed bit-error rate of 10/sup -9/. The present design indicates that GB and noise performance can be improved by using an optimum device design.     

用于移动通信的GaAs单片功率放大器

简介了移动电话单片功率放大器的设计、制作，给出了电路拓扑和版图．该三级放大电路在800－900MHz内，小信号增益＞35dB，饱和输出功率＞32dBm，效率＞34%。采用50mm全高于注入全平面干法工艺，均匀性、重复性好，工艺成品率高。     

5W ISM波段InGaP/GaAs HBT功率放大器MMIC

通过分析InGaP/GsAsHBT器件的热学和电学特点,结合HBT大功率放大器芯片在技术性能、稳定性、可靠性及尺寸等方面的要求,通过优化设计HBT功率器件单元和匹配电路,开发了一个大功率、高效率、小尺寸的ISM波段功率放大器单片集成电路。该三级放大器的各级器件单元的发射极面积分别为320μm2,1280μm2,5760μm2,芯片内部包括了输入、输出50Ω匹配电路,面积仅为1.9mm×2.1mm。放大器采用5V单电源供电,在2.4～2.5GHz频率范围内线性增益为27dB,2dB增益压缩点输出饱和功率达到37dBm,功率附加效率为46%。     

Submillimeter-Wave InP MMIC Amplifiers From 300–345 GHz

In this letter, we describe the design, fabrication, simulation, and measured performance of a single-stage and three-stage 320 GHz amplifier using Northrop Grumman Corporation's (NGC) 35-nm InP high electron mobility transistor submillimeter-wave monolithic integrated circuit (S-MMIC) process. On-wafer S-parameter measurements using an extended waveguide band WR3 vector network analyzer system were performed from 210-345 GHz. We measured 5 dB of gain for the single-stage amplifier at 340 GHz and 13-15 of gain from 300-345 GHz for the three-stage S-MMIC amplifier.     

超低噪声K波段放大器仿真设计

介绍了一种超低噪声K波段放大器的设计方法,以高电子迁移率晶体管为基础,采用3级放大拓扑结构,提出了一种改进型的负反馈网络,较好地改善了电路的增益平坦度。利用Agilent公司的微波电路CAD（计算机辅助设计）软件ADS2006对电路原理图及版图进行了仿真设计,最终实现了在工作频段19．5GHz～21．5GHz内,噪声系数小于1．5dB、增益大于30dB的优异电性能。     

A Network Modeling and Design Method for a 2- 18-Ghz Feedback Amplifier

An accurate network theory and modeling method, including feedback loop circuit parasitic and device limitations, is presented for the design of broad-band microwave feedback amplifiers. Discussed are circuit realization and measured performance in relation to VSWR, gain flatness, and stability of a 2-18-GHz three-stage amplifier.     

Monolithic GaAs transimpedance amplifiers for fiber-optic receivers

The authors describe the design of transimpedance amplifiers using GaAs MESFET technology. A GaAs transimpedance preamplifier for fiber-optic receivers has been fabricated with two gain stages and an inducer-FET load structure that reduces noise. The two-stage amplifier design provides increased open-loop gain as compared with a single-stage design, and greater closed-loop stability than a three-stage amplifier. An automatic-gain-control (AGC) circuit that varied the value of the feedback resistor was incorporated into the design