新型大动态超宽频带微波光纤通信系统

介绍了一种新型大动态超宽频带微波光纤通信系统的工作原理.详细探讨了新型大动态超宽频带微波光纤通信系统的大动态、超宽频带的实现方案以及光器件的选择及应用.最后给出了大动态超宽频带微波光纤通信系统的测试结果.     

电缆和连接器打造要求严格的连接

随着宽频带覆盖延伸到110GHz，RF和微波同轴电缆及连接器的分类符存在于各种各样需要的产品上。     

宽频带90°相移网络的设计

近几年来,由于单边带无线电通信中相移法和第三种方法的迅速发展,需要设计一种宽频带相移网络,使信号经过该网络后,所引起的相移之差近似地等于90°,所引起的相位不对称小于1°,以满足边带抑制比40分贝的要求.因而对宽频带相移网络提出了极为严     

微波部件、毫米波部件

0205951一种高定向性宽频带微带定向耦合器的研究[刊]/凌天庆//微波学报.—2001,17(4).—84～91(L)常规微带耦合器的定向性比带状线耦合器的定向性差,有多种方法可以改善微带耦合器的定向性。本文在分析了1/4波长微带耦合器接补偿电容时的带宽和定向性的基础上,提出了一种高定向性、宽频带微带耦合器的设计方法。实验证明此方法达到了预期的效果。参8     

宽带被动导引头天线系统性能分析

详细讨论了宽带被动导引头中的关键部件－超宽频带天线的性能，并在此基础上分析了三种具备大视角特性的被动测角方法。由于宽带天线没有确定的相位中心，因此不能采用通常的振幅和差式单脉冲法进行宽频带测角。本文提出的波束运算网络可用于一个宽带螺旋天线同时得到两个交叉波束的振幅－振幅式单脉冲系统中。此外，对比幅相干测向法中的测角模糊问题也进行了研究。     

微波、毫米波GaN HEMT与MMIC的新进展

综述了近几年微波、毫米波氮化镓高电子迁移率晶体管(GaN HEMT)与单片微波集成电路(MMIC)在高效率、宽频带、高功率和先进热管理等方面的应用创新进展.介绍了基于GaN HEMT器件所具有的高功率密度和高击穿电压,采用波形工程原理设计的各类开关模式的高效率功率放大器,以及基于GaN HEMT器件的高功率密度、高阻抗的特点与先进的宽带拓扑电路和功率合成技术相结合的宽频带和高功率放大器.详细介绍了微波高端和毫米波段的高效率、宽频带和高功率放大器,多功能电路和多功能集成的GaN MMIC.最后阐述了由于GaN HEMT的功率密度是其他半导体器件的数倍,其先进热管理的创新研究也成为热点.     

负载牵引技术在小型化宽频带固态功放设计中的应用

运用负载牵引技术,通过谐波平衡法,设计了倍频程带宽的小型化宽频带微波固态功率放大器。本文中的设计方法可以对功率放大器的输出功率-频率特性、实际功率增益-频率特性、功率附加效率-频率特性、中心频点的输入-输出特性等各项微波性能进行预先估计,是小型化宽频带固态功率放大器设计的一条有效途径。     

2GHz输出12W宽频带内匹配硅微波功率管

<正> 一、引言十多年来,硅微波功率管已广泛应用于微波通信、电视广播、雷达、遥测遥控及各种电子仪器、设备之中。不同功能的微波电子系统对微波晶体管提出不同的特殊要求:在电子对抗中要求宽频带微波功率管;在雷达发射单元中要求脉冲微波功率管;在微波通信中要求线性微波功率管;在地面移动通信中要求低压微波功率管。本文侧重研究宽带高效率内匹配微波功率管。它采用了网状发射极结构、扩散电阻镇流、输入输出内匹配网络、多层金属化系     

电视微波宽频带无源转发站的设计及其应用

电视微波宽频带无源转发站的设计及其应用肇庆市广播电视局冯国权该文重点介绍电视微波无源转发站的设计、安装与调试等问题。整套系统包括麒麟山同频转发和降频转发分路系统以及渔涝镇转频接收单元等设备的研制生产和安装调试，委托深圳恒星微波技术有限公司完成。建成的...     

微波反馈放大器的匹配和增益带宽的探讨

本文介绍了小信号微波反馈放大器的分析与综合。放大器采用通常的增益级框图表示和并联反馈。文中提供了全部网络元件的估算值和闭环宽频带增益、带宽和双端口的匹配值。用图解法对匹配值与增益进行了权衡。最后用实例描述了综合方法。     

Transfer Function Approximations for a New Class of Bandpass Distributed Network Structures

Characteristic functions for a new class of prototype bandpass transmission-line structures have been derived for both the maximally flat and equiripple or Chebyshev characteristics. The class of bandpass distributed structures considered in this paper consists of commensurate transmission lines with constraints in the form of a shunt open-circuited stub and/or a series short-circuited stub. The gain-bandwidth restrictions imposed by the reactance constraints have been derived and some explicit results are presented for the synthesis of this class of bandpass transmission-line networks. Results presented in this paper are directly applicable to the design of broad-band microwave passive and active networks. In particular, the results are applied to the design of broad-band matching networks for octave-band GaAs FET amplifiers.     

Continuous beam steering and null tracking with a fixed multiple-beam antenna array system

This paper describes how continuous null tracking of a target may be achieved with a fixed pattern multiple-beam forming network with a resulting improvement in tracking accuracy when compared to beam interpolation techniques. Continuous null tracking is accomplished by cascading a hybrid phasing matrix with a beam combining networks called a steering box. The steering box combines three elementary beams in the proper ratio to form a composite sum-and-difference beam which may be continuously steered throughout the coverage angle. The change in the sum-and-difference patterns as a function of steering angle is derived for different steering loci. It is shown how pattern asymmetry may be minimized or sidelobe fall-off rate maximized by the proper choice of a steering locus. Several physical realizations of steering boxes are discussed including the steering box employed in an experimental electronic scanning radar system.     

Architecture of Broad-Band Communications Systems

At present there are worldwide efforts directed towards a services-integrated broad-band network. The first section of this paper describes different solutions of broad-band network components such as subscriber premises networks, local loops, subscriber exchanges, and trunk networks. The design of these components was taken from various proposals and broad-band communication field trials carried out in several countries up to 1984. In the second section, we consider the possibilities and implications of integrated optical components and of optical coherent communication techniques for broad-band networks in the far future.     

一种新型宽带平面和差网络

提出了一种新型的基于环形电桥结构的宽带平面和差网络。首先提出了一种新型的宽带微带/槽线转换结构,然后将该结构引入到传统的环形电桥结构中,优化设计了一种改进型环形电桥,最后采用四个改进的环形电桥构建了双平面和差网络。测试结果表明:在4.05～7.425GHz的频率范围内,八个端口的驻波均小于2,输入端口之间的隔离度均在20dB以上,输出端口之间的隔离度大于30dB,和端口的插入损耗小于0.5dB,差端口的零值深度小于-30dB。该和差网络具有性能优良、结构简单、制作成本低等优点,在宽频带单脉冲雷达天馈系统中得到了成功的应用。     

一种新型双平面和差网络设计

针对传统的八端口双平面和差网络存在对交叉差端口的问题,文中提出了一种新型的七端口双平面和差网络结构。该网络由三个平面魔T和一个Wilkinson功分器组成,运用微波网络理论,推导了该网络的S参数矩阵,从理论上证明了网络结构设计的正确性。基于该网络结构,采用三枝节分支线耦合器、宽带90°移相器和Wilkinson功分器构建了一种七端口宽带双平面和差网络,测试结果表明：该网络在2.22 GHz~3.90 GHz的频段内,具有良好的传输、隔离以及和差运算特性。该网络结构避免了交叉差端口,具有结构简单、制作成本低等优点,可以在双平面单脉冲天线系统中得到广泛应用。     

Introduction of Optical Broad-Band Networks in France

Whereas optical fibers are today the most successful transmission medium in the long-haul links of the telecommunication networks, it is less obvious how to introduce them in local broad-band networks. The French Administration of Telecommunication adopted an evolutionary concept in order to be able to install an optical cable infrastructure in its videocommunication networks. This approach will permit the French Administration to explore quickly a wide range of interactive services, enabled by the star-type structure of the optical broad-band networks, and to evaluate their demand.     

Data Transmission Implementation on Broad-Band Networks

Broad-band networks present many advantages for the implemention of data transmission circuits. Whereas communication system concepts are universally applicable, there are many unique details and practial considerations involved in design and operation of broad-band networks. This paper describes broad-band configurations and their system design implications and includes a discussion of current modem designs, spectral occupancy, and modulation characteristics configurations and protocols, interference, and error control, as well as broad-band network control and maintenance. In addition, a data transmission network addressing many of the basic factors and providing multiple services is described.     

Role of Satellites in Broad-Band Interactive Cable Networks

The possible role of satellites in broad-band interactive communications networks is described primarily in terms of a long distance transmission facility interconnecting several such networks over a wide geographical area. Discussion of the interface between the cable and satellite facilities is presented as well as a review of current broad-band operational and experimental uses of satellites which might be applicable to future system design.     

Variance and bias of angle estimation radars

Calculations are presented for the variance and bias of three related angle estimators caused by propagation through a layer containing random index of refraction fluctuations. The usual amplitude and phase sum-and-difference techniques, as well as a third amplitude comparison technique are considered. One-dimensional integral expressions for the variance and bias are given for Gaussian antenna patterns, isotropic turbulence, and targets near the antenna boresights. Results show that for the same total aperture the variances of amplitude and phase comparison monopulse radars are equal for arbitrary turbulence spectrum. The biases for the amplitude and phase sum-and-difference estimators are related by a constant multiplying factor while the bias for the amplitude comparison estimator is generally larger than the bias of the amplitude sum-and-difference estimator.     

Overview of a Broad-Band Local Area Network Protocol Architecture

The protocol architecture of a broad-band local area network (LAN) must consider a realm of issues ranging from user device requirements to the characteristics of the underlying broad-band cable medium. The primary environment for which these protocols are intended consists of a collection of multichannel broad-band local networks, connected by point-to-point links. This paper describes one example of a broad-band LAN protocol architecture, LocalNet (^TMSytek Inc.). Particular attention is paid to those design decisions and practical considerations which were prompted by the intended environment.