一种宽带光纤喇曼放大器的设计

在PTDS(photonic transmission design suite)仿真平台上，对宽带光纤喇曼放大器(FRA)的设计及泵浦源对增益的影响进行了研究。提出了一种宽带FRA的设计方法及增益控制方法，进而设计了增益起伏小于ldB、1dB带宽为80nm的S波段宽带FRA，并且通过增益控制方法可以使FRA的增益灵活地改变。     

宽带限幅放大器的研制

从双极型晶体管Gummel-Poon模型出发,综合考虑晶体管的器件结构、工作状态和参数提取条件等完成参数提取,运用优化算法对提取参数进行局部和全局优化,给出了得到的GP模型参数值.以此为基础采用差分放大电路形式,完成限幅放大器电路结构设计并对其进行分析,运用ADS仿真软件对限幅放大器进行仿真优化并进行了流片.结果表明,设计完成的限幅放大器在10～300 MHz工作频率内的小信号电压增益最大值大于25 dB,带内平坦度小于±1 dB,限幅输出电压约为1.2 V.     

A Design Theory for Optimum Broadband Reflection Amplifiers

The design procedure for optimum broadband negative-resistance amplifiers is given, by reference to the work of Fano, on the broadband matching of arbitrary impedances. Complete sets of curves are given which indicate the limits on the gain-bandwidth performance which can be achieved for a particular negative-resistance device, while also showing the ripple in gain and the resulting phase response obtained. The optimum amplifiers are also compared with others of the same class, and it is found that considerable advantage in terms of ripple and phase response can be gained by using nonoptimum designs in certain cases. The paper also includes explicit formula for the element values of the matching network applicable to both optimum and nonoptimum designs. A design example is given for a tunnel-diode amplifier.     

宽带功率放大器的非线性研究

功率放大器更多时候是工作在饱和区,此时其非线性特性成为需要考虑的重要因素之一。在宽带功率放大器中,低频段信号的二次谐波也在其工作频带之内。当前级功放模块产生的二次谐波与基频信号同时进入末级功放时,产生的二阶交调信号频率与基频相同,对输出造成影响。文中从理论上分析了放大器的非线性表现形式以及产生的机理,介绍了 X参数的优势,利用NVNA网络分析仪提取X参数,并且使用ADS软件进行谐波平衡仿真,研究了宽带功率放大器中二次谐波的相位对基频功率的影响。     

小型化高可靠宽带功放技术的研究

随着通信技术的发展,机载设备的通信频带越来越宽,而体积却越来越小,同时要求有较高的可靠性。功放作为其中体积最大、耗电最多、发热最厉害的模块,实现小型化和高可靠对整个机载设备至关重要。本文从宽带技术、高可靠技术和宽带电路稳定性设计三方面论述了在宽频带要求下如何实现功放的小型化和高可靠。     

应用于无线通信的宽带Doherty 功率放大器

在分析传统Doherty 合路结构对其带宽限制的基础上,提出一种新型负载调制网络。该负载调制网络为平行式负载调制和一段并联的1/4 波长短路线相结合的结构方案,经推理可有效弥补传统Doherty 负载调制网络中的带宽限制效应从而达到拓展带宽的目的。为验证设计方案的实际可行性,采用两个10 W 的GaN HEMT 晶体管设计了一款应用于无线通信的宽带Doherty 功率放大器并进行了实物测试,测试结果表明该功率放大器的工作带宽为1. 6～2. 6 GHz,整体频带内饱和输出功率大于41 dBm,饱和漏极效率最大能达到56%,输出功率回退6 dB 处的漏极效率在35%～38%之间,邻道功率比(ACPR)优于-45 dBc,表明该设计方案能够达到预期效果。     

Theoretical Analysis of Intermodulation Distortion of Reflection-Type IMPATT Amplifiers

The basic equations for a reflection-type IMPATT amplifier are used to derive expressions for the output when the amplifier is driven by a multifrequency input signal. The third-order intermodulation distortion is expressed and graphically presented for various diode, circuit, and signal parameters. The results provide a guideline for designing amplifiers with minimum intermodulation distortion or prescribed distortion level.     

Design and Analysis of Broadband Dual-Gate Balanced Low-Noise Amplifiers

In this paper, we present three MMIC low-noise amplifiers using dual-gate GaAs HEMT devices in a balanced amplifier configuration. The designs target three different frequency bands including 4-9 GHz, 9-20 GHz, and 20-40 GHz. These dual-gate balanced designs demonstrate the excellent qualities of balanced amplifiers in terms of stability and matched characteristics, while demonstrating higher bandwidth than designs with a single-stage common-source device. Additionally, noise performance is excellent, with the 4-9 GHz LNA demonstrating <1.75 dB noise figure (NF), the 9-20 GHz LNA <2.75 dB NF and the 20-40 GHz LNA <2.5 dB NF. Demonstrating high gain and excellent bandwidth, the dual-gate devices seem a logical choice for the balanced amplifier topology.     

宽带拉曼光纤放大中的多泵浦源选择方法

理论分析了拉曼光纤放大谱与多波长泵浦光功率和波长的关系.考虑到泵浦光与泵浦光,泵浦光与信号光的拉曼相互作用,得出一个增益数组,增益数组就是离散的宽带拉曼光纤放大增益谱.对任何形态的宽带拉曼光纤放大增益谱,可以设定对应的增益数组,把泵浦光功率和波长组成二维坐标系,遍取坐标系中的各点,求出各组点对应的增益数组,找出最接近设定的增益数组,这组泵浦光功率及波长就是最优的解决方案.     

宽带宽与新波段光纤放大器进展

宽带、高速、长距离和智能化是目前光纤通信系统发展的趋势所在。迅速膨胀的信息服务量使宽带成为最迫切的需求,新波段与长增益带宽光纤放大器的研究炙手可热。本文阐述了近期各波段光纤放大器以及拉曼放大器的进展,并揭示了光纤放大器向短波段和混合型发展的趋势。     

宽带宽与新波段光纤放大器进展

宽带、调整、长距离和智能化是目前光纤通信系统发展的趋势所在，迅速膨胀的信息服务量使宽带成为最迫切的需求，新波段与长增益带宽光纤放大器的研究炙手可热，本文阐述了近期各波段光纤放大器以及拉曼放大器的进展，并揭示了光纤放大器向短波段和混合型发展的趋势。     

VHF/UHF宽带低噪声放大器设计

介绍了VHF/UHF宽带低噪声放大器的设计与实现。利用软件对放大器的电性能及有源芯片的沟道温度进行了仿真、优化。电路制作完成后,与实际测试结果进行了对比分析,并且结合不同电路形式,开发了系列化放大器。该系列放大器采用GaAs PHEMT管芯,微波薄膜工艺,封装在密封的金属或陶瓷管壳中,性能优异,体积小、噪声低、动态范围大,可适应目前微波整机向小型化、高可靠方向发展的需求,有着广泛的应用前景。     

Use of Transistor-Simulated Inductance as an Interstate Element in Broadband Amplifiers

The properties of a transistor in the inverted common-collector connection, and the use of this connection as an interstage element in broadband amplifiers, are described. A simple amplifier synthesis procedure using a T model of the transistor, and experimental results obtained with a VHF amplifier, are presented. An extension of the synthesis using y-parameter characterization is also described; this procedure is useful in the synthesis of amplifiers consisting of many stages or when the validity of the simple T model is questionable. The use of the simulated inductance of the inverted common-collector connection in monolithic integrated circuits is considered and design examples of monolithic microwave amplifiers are given.     

掺铒光纤放大器的理论分析：二能级近似

本文针对存在和不存在受激态吸收两种情况分别推导了当有多束光在掺铒光纤中传播时掺铒光纤放大器的速率方程组，并通过合理的近似交过些方程转换成二能级模型下的一组方程。对１４８０ｎｍ泵浦的掺铒光纤放大器进行了研究。理论分析结果与实验结果一致。     

A Highly Linear Broadband CMOS LNA Employing Noise and Distortion Cancellation

A broadband inductorless low-noise amplifier (LNA) design that utilizes simultaneous noise and distortion cancellation is presented. Concurrent cancellation of the intrinsic third-order distortion from individual stages is exhibited with the common-gate and common-source cascade. The LNA is then limited by the second-order interaction between the common source and common gate stages, which is common in all cascade amplifiers. Further removal of this third-order distortion is achieved by incorporating a second-order-distortion-free circuit technique in the common gate stage. Implemented in 0.13 m CMOS technology, this LNA achieved 16 dBm in both the 900 MHz and 2 GHz bands. Measurements demonstrate that the LNA has a minimum internal gain of 14.5 dB, noise figure of 2.6 dB from 800 MHz to 2.1GHz while drawing 11.6 mA from 1.5 V supply voltage.     

一种基于高斯近似的极化码打孔算法

现有的极化码打孔算法均未考虑信道构造过程对算法性能的影响,针对这一问题,该文提出一种基于高斯近似的极化码打孔算法(GAPPC)。首先将高斯近似作为极化码构造算法,分析高斯近似与打孔算法的关系,以降低信道构造输出值为目标,引入高斯修正因子,推导出改进的高斯近似函数。然后将改进的高斯近似函数引入信道构造,对极化子信道进行排序获得信道可靠性排序集合。最后依据信道容量关系确定映射规则,选出打孔比特集合和冻结比特集合,完成打孔极化码的构建。实验结果显示,在不同的码长和码率下,误帧率和误码率均获得显著降低。     

一种基于高斯近似的极化码打孔算法

现有的极化码打孔算法均未考虑信道构造过程对算法性能的影响,针对这一问题,该文提出一种基于高斯近似的极化码打孔算法(GAPPC).首先将高斯近似作为极化码构造算法,分析高斯近似与打孔算法的关系,以降低信道构造输出值为目标,引入高斯修正因子,推导出改进的高斯近似函数.然后将改进的高斯近似函数引入信道构造,对极化子信道进行排序获得信道可靠性排序集合.最后依据信道容量关系确定映射规则,选出打孔比特集合和冻结比特集合,完成打孔极化码的构建.实验结果显示,在不同的码长和码率下,误帧率和误码率均获得显著降低.     

Fine Grain Spectrum Analysis of Pulsed Microwave Amplifiers

With the advent of microwave transmitter systems requiring high spectral purity, it has become important to control the interline noise and modulation products in the fine grain spectrum of CW or pulsed microwave amplifiers. Some of the causes of interline noise and modulation in high-power microwave amplifiers such as klystrons, TWT's and coaxial triodes are reviewed in this paper. A spectrum analyzer capable of resolving interline noise and modulation products in CW or pulsed microwave spectrums is described. This analyzer has a dynamic range of better than 50 db and a resolution of less than 2 cps. Some typical measurements made on transmitters operating in the UHF and L-band regions are presented.     

微波固态宽带放大器机助设计方法的研究与进展

本文综述小信号微波固态宽带放大器机助设计方法的研究与进展,重点介绍以实频技术为基础的实频数据设计法。对发展动向作了简要分析,阐明了进一步探讨CAD方法对促进我国MIC及MMIC发展的意义。