1～6GHz宽带低噪声放大器的研制

该放大器采用负反馈的设计原理，利用ＥＥＳＯＦ进行ＣＡＤ设计，选用噪声较小增益较高的日本ＦＵＪＩＴＵ公司的ＧａＡｓ晶体管（ＦＨＸ１４型）。通过主调试，解决了研制中两个难题，即多级级联与稳定性和可靠性难题，从而使该放大器达到满意的性能指标。     

X波段GaAsMESFET功率放大器的设计

给出了根据给定的电路拓扑结构和ＦＥＴ的Ｓ参数，借用Ｓｍｉｔｈ圆图设计思想进行放大器设计的机辅设计方法，并用该方法设计了Ｘ波段ＧａＡｓＭＥＳＦＥＴ功率放大器。实验调试结果表明运用该方法能很好地满足设计指标且简单有效。     

CATV共用天线放大器前端立柜介绍

本文介绍了ＣＡＴＶ大功率共用天线放大器前端立柜，它采用了ＶＨＦ／ＵＨＦ分频道先放大、后混合的方案，解决了ＶＨＦ／ＵＨＦ频道间隔离度差的难题，输出功率大，是大系统共用天线理想的前端设备。     

掺铒光纤放大器特性分析及长度优化设计

掺饵光纤放大器（ＥＤＦＡ）是光纤通信系统中的关键器件之一。文中从ＥＤＦＡ的基本理论出发，对ＥＤＦＡ的各种特性进行了计算机模拟分析，并研究了ＥＤＦＡ的长度优化设计，实验结果与理论计算相吻合。     

THE OUTPUT OPTICAL FIELD INTENSITY DISTRIBUTION FORMED BY AN OPTICAL FIBER END

ＴＨＥＯＵＴＰＵＴＯＰＴＩＣＡＬＦＩＥＬＤＩＮＴＥＮＳＩＴＹＤＩＳＴＲＩＢＵＴＩＯＮＦＯＲＭＥＤＢＹＡＮＯＰＴＩＣＡＬＦＩＢＥＲＥＮＤ￥ＹＵＡＮＬｉ－Ｂｏ（Ｄｅｐａｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，ＨａｒｂｉｎＥｎｇｉｎｅｅｒｉｎｇＵｎｉｖｅｒｓｉｔｙ...     

光放大器的最新进展

本文叙述了国外研制的几咱光放大器的最新水平。介绍了分波段结构的超宽带石英基ＥＤＦＡ、碲化物ＥＤＦＡ、混合放大器、并联结构的宽带ＥＤＦＡ、半导体光放大器的最新。阐述了光放大器技术的发展趋势。     

用DAC设计数字可编程电流源

ＤＡＣ７６４４（Ｂｕｒｒ－Ｂｒｏｗｎ公司１６位四电压输出Ｄ／Ａ变换器）设计的４～２０ｍＡ数字控制的电流源电路示于图１。ＤＡＣ７６４４提供一差分基准输入以及围绕输出放大器的一开环配置。围绕输出放大器的开环配置允许把晶体管放置在环路中实现一数字可编程的单向电流源。差分基准也可利用于满标和零标电流的编程。ＤＡＣ７６４４的单电源工作连接图示于图２,逻辑真值表见表１。其中ＶＯＵＴＡＳｅｎｓｅ：ＤＡＣＡ输出放大器倒相输入;ＶＯＵＴＡ：ＤＡＣＡ电压输出;ＶＲＥＦＬ　ＡＢＳｅｎｓｅ：ＤＡＣＡ和Ｂ某准低感测输入;…     

测量散射参数的交互换位双信号方法及其应用

叙述了外内向功率波复数比的测量方法,给出了散射参数测量的交互换位双信号测量线方法。用此方法测量了双栅ＧａＡｓＭＥＳＦＥＴ适用散射参数,并用它设计Ｓ波段混合集成双栅ＧａＡｓＭＥＳＦＥＴ可控增益放大器。测试结果与设计吻合。     

高功率Ku波段FET放大器

高功率Ｋｕ波段ＦＥＴ放大器《ＭｉｃｒｏｗａｖｅＪｏｕｒｎａｌ》１９９４年第３７卷第８期报导了新的系列Ｋｕ波段ＣａＡｓＦＥＴ功率放大器，其输出功率５０Ｗ，增益为６３ｄＢ。高功率Ｋｕ波段ＦＥＴ放大器可用于地面站的上行线路，取代行波管放大器（ＴＷＴＡ）。该...     

信息通信英语新缩略语[3]

ＥＤＦＡ(Ｅｒｂｉｕｍ -ＤｏｐｅｄＦｉｂｅｒＡｍｐｌｉｆｉｅｒ,掺铒光纤放大器 )利用光纤中掺入稀土元素饵而引起的光增益机制来实现光信号放大的光纤线路元件。ＥＤＦＦＡ(Ｅｒｂｉｕｍ -ＤｏｐｅｄＦｌｕｏｒｉｄｅＦｉｂｅｒＡｍｐｌｉｆｉｅｒ,掺铒氟化物光纤放大器 )ＥＴＥ(ＥｑｕｉｖａｌｅｎｔＴｅｌｅｐｈｏｎｅＥｒｌａｎｇｓ,等效电话占线小时呼 )一种通话计量单位。通信中话务量常以爱尔兰小时呼表示。ＥＴＳＩ(ＥｕｒｏｐｅａｎＴｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎＳｔａｎｄａｒｄｓＩｎｓｔｉｔｕｔｅ,欧洲电信标准协会 )…     

一种提高GaAs HBT放大器增益带宽积的技术

提出了一种提高GaAsHBT共射共基宽带放大器增益带宽积的技术,给出了一种宽带补偿的改进型共射共基宽带增益单元。小信号分析表明:在相同半导体工艺条件下,基于这种改进型电路结构的放大器具有更高的增益带宽积。采用2μmInGaP/GaAsHBT晶体管工艺,分别设计了无高频损耗补偿和具有高频损耗补偿电路的共射共基放大器,并成功流片,在同样测试条件下,新的增益单元其增益带宽积达到了原来的近400%。     

Bandwidth enhancement of transimpedance amplifier by acapacitive-peaking design

Using a capacitive-peaking (C-peaking) technique to increase the bandwidth of a transimpedance amplifier has been proposed. An analytical model for determining the peaking capacitance in the Butterworth-type transimpedance amplifier design has been derived. Based on this approach, we can design a larger bandwidth of a transimpedance amplifier. The low-frequency transimpedance gain in our fabricated amplifier is 0,95 kΩ, and the 3 dB bandwidth of the transimpedance amplifier is enhanced from 1.1 to 2.3 GHz without sacrificing its low-frequency gain by this C-peaking technique     

A BiCMOS wideband operational amplifier with 900 MHz gain-bandwidth and 90 dB DC gain

A fully differential operational amplifier has been designed and fabricated for a novel high resolution and high frequency analog-to-digital converter(>12-bit). The amplifier mainly consists of folded cascode structure with current source as output loads and common-mode feedback circuits. The technique of feedforward compensation is used in order to improve the settling time and gain bandwidth (GBW) of this amplifier. This amplifier is integrated in 0.8 mm BiCMOS process with an active die area of 0.1 mm². The DC gain of this amplifier is 90 dB. The GBW and phase margin of this amplifier is 900 MHz and 47°, respectively. The power dissipation is minimized by using BiCMOS technology and is about 25 mW for 2 pF load capacitance. This level of performance is competitive with CMOS and BiCMOS operational amplifier circuits previously reported by nearly two orders of magnitude.Ecole Polytechnique of the University of Montreal     

The computer analysis of a FEL amplifier with two-element circularly polarized and self-adaptive wiggler

In this paper, the problems of a FEL amplifier with two-element circularly polarized and self-adaptive wiggler are discussed. In order to get the optimum amplifier, the relations between the characteristic quantities of the amplifier and the amplifier structure parameters are studied by computer simulation. The results show that the influence of the free-drift-space and two-interaction region structure on the gain of the amplifier is sensitive. The results are also compared with one-element wiggler.     

An analytic approach for CDMA output of feedforward power amplifier

In this paper, a novel method is introduced to predict the Code-Division Multiple-Access (CDMA) output spectrum of an RF power amplifier linearized with feedforward technique based on transfer function. In this method, an RF power amplifier is modeled mathematically by nonlinear complex envelope transfer function based on AM-AM and AM-PM distortion diagrams. Using this model, analytic expressions of CDMA output spectrum of power amplifier is calculated. Having mathematical model of RF power amplifier leads to derive analytic expressions for InterModulation (IM) products in feedforward amplifier. Based on these expressions, IM products are related to nonlinear complex envelope transfer function of feedforward amplifier. Then, CDMA output spectrum of feedforward linearization technique is predicted. The loops imbalances in feedforward technique are considered in analysis. Finally, the results of derived expressions in MATLAB software are compared with ADS simulations results and good agreements were achieved. Employing this method gives insight for feedforward analysis and loops imbalances effects in feedforward amplifier for CDMA applications.     

Design and analysis of a high efficiency linear power amplifier

A high efficiency linear power amplifier is introduced based on the idea of Switch-Linear Hybrid (SLH) power conversion. The SLH power amplifier developed from the conventional class B power amplifier, while the class B configuration power unit in the SLH power amplifier is fed by a dynamic switching power supply, not the usual constant DC power supply. Thus, the efficiency of the class B configuration power unit in SLH power amplifier can be greatly improved. By combining linear power amplifier with switching power supply, the SLH power amplifier has synthetic performance of high fidelity, high efficiency and excellent dynamic characteristics. In this article, analysis of SLH power amplifier is performed, especially focusing on its linear power unit which is the core of SLH power amplifier. Design considerations are also presented parallel with the analysis. Both the theoretical analysis and experimental results verify the validity of SLH power amplifier.     

基于GaN 的3. 4~ 3. 6 GHz 高增益Doherty 功率放大器

基于两级功率放大器架构,设计了一款平均输出功率为37 dBm(5 W)的高增益Doherty 功率放大器。 该器件通过增加前级驱动功率放大器提高Doherty 功率放大器的增益,采用反向Doherty 功率放大器架构,将λ/4 波 长传输线放置在辅助功放后端,相位补偿线放置在主功放前端,并使主功放输出匹配网络采用双阻抗匹配技术实现 阻抗变换,如此可扩宽功率放大器的工作带宽。连续波测试结果显示:3. 4~3. 6 GHz 工作频段内,饱和输出功率在 44. 5 dBm 以上,功率饱和工作点PAE 在43. 9%以上;在平均输出功率(37 dBm,5 W)工作点,回退量大于7. 5 dB,功 率附加效率PAE 为36. 8%以上,功率增益在31 dB 以上。     

L波段小信号放大器ADS设计与仿真

对小信号晶体管放大器的设计步骤、设计理论进行了阐述,利用ADS软件通过实例详细地设计了L波段小信号放大器,并给出了仿真结果.仿真结果表明,放大器匹配电路设计完全满足性能指标要求.本文提出的利用ADS软件对L波段的LNA和小信号功率放大器的设计方法可以加速放大器产品化进程,具有重要的实用价值.这种放大器主要应用于微波中继、数字音频卫星直播、全球定位系统等无线系统中.     

实用运算放大器网络中的虚地性质

本文提出用一个理想电压控制电流源(VCCS)并接于嵌在一个倒相放大器电路中的实际运算放大器(OP.amp)输入端,虚地性质(VGP)可以扩展到使用的运算放大器单位增益带宽那样高的频率.文中给出用真正运算放大器的VCCS的实用电路.用互补变换法可得出非倒相放大电路图.     

射频功率放大器前馈线性化技术研究

在移动通信等领域,功率放大器的性能是决定整个通信系统性能的关键因素。而功率放大器的高线性度尤为关键。在设计射频功率放大器时,通常采用前馈技术实现高线性的要求。介绍了功率放大器前馈线性化技术的基本原理,利用该技术设计了一个线性功率放大器,并对电路提出改进方案。实验表明,该设计实现了功率放大器高线性,大功率输出的要求,该技术对改善功放的线性度有一定的效果。