A Broadband Dual-Polarized Planar Antenna for

A Broadband Dual-Polarized Planar Antenna for

2G/3G/LTE Base Stations

YueHui Cui,RongLin Li,and HuanZhan Fu Abstract—A broadband dual-polarized planar antenna is proposed for 2G/3G/LTE base stations.The dual-polarized antenna is composed of two perpendicularly crossed bow-tie dipoles.Each bow-tie dipole is excited by a microstrip stub that is directly fed by a coaxial line,making the dual-polar-ized antenna full planar.Due to the coupling between two crossed bow-tie dipoles,a broad bandwidth is achieved.It is shown that the dual-polar-ized antenna has a bandwidth of45%(1.7–2.7GHz)for return loss15 dB with an isolation of higher than30dB between two polarization input ports.The dual-polarized antenna has a half-power beam width(HPBW) of around65and an average gain of8.5dBi for slant polarizations. An8-element dual-polarized planar antenna array is developed for base station applications.A bandwidth of56%(1.63–2.9GHz)is obtained for the antenna array.The antenna gain of the array is about16dBi and the HPBW is for each polarization.

Index Terms—Base station antenna,broadband antenna,dual-polarized antenna,planar antenna.

I.I NTRODUCTION

In recent years,a number of broadband dual-polarized antennas have been developed for base station applications[1]–[21].The dual-polar-ized antennas can be roughly divided into two categories:1)patch an-tennas[1]–[13]and2)crossed-dipole antennas[14]–[21].The dual-po-larized patch antennas normally have a multilayer structure which may include coupling slots(such as H-shaped slot[1]–[6]or C-shaped slot [7]),feeding probes(such as L-shaped probe[8]–[10]or meandering probe[11]),and/or a feeding network[3]–[5],[10],[12],[13].Obvi-ously the dual-polarized patch antennas involve a complicated con-?guration.The crossed-dipole antennas may require an absorber[14], wire bridges(or wire bonding)[15],[16],shorting pins[17],[18],or -shaped probes[19],[20].None of these patch antennas and crossed-dipole antennas has a full planar con?guration.Recently we presented a full planar broadband dual-polarized antenna in[21];but it needs two separate antenna elements,making the antenna topology incompact. In this communication,we propose a full planar dual-polarized an-tenna with a more compact con?guration.The antenna consists of two crossed bow-tie dipoles which are excited by a pair of microstrip stubs. Both of the crossed dipoles and the microstates stubs are printed on a single substrate,making the antenna full planar.It will be shown that the antenna achieves a bandwidth of45%for return loss

and an isolation of higher than30dB.The dual-polarized planar an-tenna is described in Section II.An8-element dual-polarized planar antenna array is presented in Section III.

Manuscript received February27,2014;revised May13,2014;accepted May 20,2014.Date of publication June12,2014;date of current version September 01,2014.This work was supported in part by the National Natural Science Foun-dation of China(61372009),in part by the Fundamental Research Funds for the Central Universities(2013ZP0022),and in part by ZTE Corporation.

Y.H.Cui and R.L.Li are with the School of Electronic and Information En-gineering,South China University of Technology,Guangzhou510641,China (e-mail:lirl@https://www.wendangku.net/doc/ff12544228.html,).

H.Z.Fu is with ZTE Corporation,Xi’an,China.

Color versions of one or more of the?gures in this communication are avail-able online at https://www.wendangku.net/doc/ff12544228.html,.

Digital Object Identi?er10.1109/TAP.2014.2330596Fig.1.Con?guration of the broadband dual-polarized planar antenna.

II.B ROADBAND D UAL-P OLARIZED P LANAR A NTENNA

A.Antenna Con?guration

The con?guration of the broadband dual-polarized planar antenna is illustrated in Fig.1.The antenna consists of two perpendicularly crossed bow-tie dipoles for slant polarizations.Each arm of the antenna has the form of an isosceles triangle attached with a semicircle. One half of each bow-tie dipole is printed on the front side of a dielec-tric substrate(Rogers4350B,and) while the other half is etched on the backside of the substrate.A50-ohm microstrip stub is introduced to excite each bow-tie dipole.One end of the microstrip stub is extended from one half of the bow-tie dipole while the other end is connected at the ports.There is a metallic hole on one half of the polarized bow-tie dipole and a non-metallic hole on one half of the polarized bow-tie dipole.At Port1,the outer conductor of the coaxial cable goes through the metallic hole and is soldered on the half of polarized bow-tie dipole printed on the front side of the substrate while the inner conductor is connected to the microstrip stub printed on the back side of the substrate.At Port2, the inner conductor of the coaxial cable goes through the non-metallic hole and is connected to the microstrip stub printed on the front side of the substrate while the outer conductor is soldered on the half of polarized bow-tie dipole printed on the back side of the substrate.Note that the metallic hole and the non-metallic hole have no in?uence on the performance of the antenna.This type of feeding structure avoids using any wire bridge,wire bonding,shorting pin,or feeding probe,making the dual-polarized antenna planar and lightweight.The dual-polarized antenna is placed above a metallic re?ector that is shaped for base station applications.Four plastic poles are employed to support the dual-polarized antenna.

B.Analysis and Design

To understand the mechanism for broadband performance of the dual-polarized planar antenna,we start with a single bow-tie dipole excited by a voltage source.The return loss simulated for the single bow-tie dipole is shown in Fig.2.(All simulations were carried out in

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Fig.2.Return Loss simulated for a single dipole,a single dipole with one half of another dipole,a voltage-source fed cross dipole,and a microstrip stub-fed cross dipole.

Fig.3.Effect of the angle of the dual-polarized planar antenna on the parameters(and).

this communication using Ansoft HFSS v.13.)It can be seen that the impedance matching of the single bow-tie dipole is not good.As one half of another bow-tie dipole is introduced,the impedance matching of the original bow-tie dipole is improved.The impedance matching is further improved when a whole bow-tie dipole is added to the original bow-tie dipole to form a dual-polarized antenna.Therefore it can be concluded that the improvement of impedance matching of the dual-po-larized antenna is attributed to the coupling between two perpendic-ularly crossed bow-tie dipoles.The microstrip stub feeding structure further enhances the impedance bandwidth.Note that the microstrip stub feeding structure is necessary for a simple full planar con?gura-tion since the voltage-source feed may need a balun.

For the design of a dual-polarized planar antenna,there are four important geometric parameters which need to be determined:1)the height(h)of the isosceles triangle,2)the top angle of the isosceles triangle,3)the radius(r)of the semicircle,and4)the height(H)of the dual-polarized planar antenna above the re?ector.The height(h)is de-cided by the operating frequency of the antenna.For the2G/3G/LTE applications,the center frequency is2.2GHz.By simulation,h is found to be16mm or,where is the free-space wavelength at2.2 GHz.The top angle plays an important role for the broadband performance.The effect of on parameters(and )is demonstrated in Fig.3.It is found that as the angle increases, the coupling between two crossed bow-tie dipoles increases;thus the impedance matching is improved and the bandwidth is enhanced.How-Fig.4.Effect of the shape of the semicircle of the dual-polarized planar antenna on the parameters(and).

Fig.5.Effect of the height(H)of the dual-polarized planar antenna above the re?ector on the parameters(and).

ever,when the angle is increased to near90,two crossed bow-tie dipoles become too close,making the parameters worse.The optimal value for is found to be.

To investigate the effect of the shape of the attached semicircle on the broadband performance,we replace the semicircle with a semi-ellipse that has a semi-major axis and a semi-minor axis.The top angle of the isosceles triangle is?xed at.As indicated in Fig.4,the best impedance matching is obtained when,i.e., the semi-ellipse becomes a semicircle.The radius(r)of the semicircle is found to be15.4mm or,which leads to a total length of

for the bow-tie dipoles.The total size of the dual-polarized antenna is56mm56mm or,which is comparable to that in[17],smaller than those in[14]

,[15],[18], [19]and[20].Note that the orientation for the dual-polarized antenna in[17]is for vertical and horizontal polarizations,but not for slant polarizations.

The height(H)of the dual-polarized planar antenna above the re-?ector also has impact on the impedance matching.Fig.5shows the parameters for different values of H.It is found that the optimal height is or,approximately a quarter wavelength in the operating frequency band.

From Figs.3–5,we can see that the isolation(in dB)be-tween Ports1and2is higher than30dB.The high isolation is an in-herent property for this type of crossed-dipole antenna[14]–[20].The

Fig.6.Effect of the two feeding coaxial cables on the parameters of the

dual-polarized planar antenna.

TABLE I

O PTIMIZED V ALUES FOR THE G EOMETRIC P ARAMETERS O F T HE B ROADBAND

D UAL -P OLARIZED P LANAR A

NTENNA

Fig.7.A prototype of the dual-polarized planar antenna:(a)perspective

view,(b)backside view.

effect of two feeding coaxial cables has been taken into account in the simulation.The outer conductor of each coaxial cable was modeled using a metallic cylinder which is terminated at the re ?ector.Simula-tion shows that the leaky current on the outside of the outer conductor is very small;thus its effect on antenna performance is negligible.As in-dicated in Fig.6,the S parameters of the antenna with coaxial cables are similar to those without the coaxial cables.All geometric parameters optimized for the dual-polarized planar antenna are listed in Table I.C.Experimental Results

A prototype of the broadband dual-polarized planar antenna is dis-played in Fig.7.A 20-cm-long ?exible coaxial line (RG-316)is used to feed the antenna for each polarization.The re ?ector is made of an aluminum alloy plate with a thickness of 1mm.Four plastic poles of 8-mm diameter are employed to support the dual-polarized planar an-tenna.The measured parameters (

,,and )are com-pared with simulated results in Fig.8;good agreement is observed.

The measured bandwidth for

or or return loss is about 45%(1.7–2.7GHz),which is wider than

those

Fig.8.parameters (,,and )simulated and measured for the

dual-polarized planar

antenna.

Fig.9.Gain values and HPBWs of the dual-polarized planar antenna.

in [15](23.7%for ),[18](23.5%for )and [20]

(24.9%for

),and comparable to those in [16](57.5%for

),[17](46.5%for ),[19](65.9%for )and [21](53%for ).The measured isola-tion (

in dB)is higher than 30dB.The radiation pattern mea-surement for the dual-polarized planar antenna was carried out using a SATIMO near-?eld antenna measurement system (SG24)at the Speed Communication Technology Corporation Ltd.,Shenzhen,China.The antenna gain values and the half-power beamwidths (HPBWs)in the

x-z plane for slant

polarizations are depicted in Fig.9.The av-erage gain is about 8.5dBi and the HPBWs are around 65.Fig.10shows the radiation patterns simulated and measured at 1.7,2.2,and

2.7GHz for

polarization.(The radiation patterns for po-larization are similar because of geometric symmetry.)The measured radiation patterns agree well with simulated results.The cross-polar-ization level is about 20dB.

III.D UAL -P OLARIZED P LANAR A NTENNA A RRAY

A.Array Geometry

An 8-element dual-polarized planar antenna array is developed for 2G/3G/LTE base station applications.The geometry of the antenna array is depicted in Fig.11(a).The element spacing is 110mm,which is approximately (where the is the free-space wave-length at the highest frequency 2.7GHz).The element spacing was optimized for a maximum gain but without the appearance of grating lobes.Fig.11(b)shows a prototype of the 8-element dual-polarized planar antenna array.An 8-way power divider is employed to feed the

Fig.10.Radiation patterns of the dual-polarized planar antenna simulated and measured at(a)1.7GHz,(b)2.2GHz,and(c)2.7GHz.

antenna array for each polarization.An80-cm-long RG-316?exible coaxial line is used to connect each element for each polarization to the power divider.

B.Experimental Results

The measured parameters(,,and)of the8-el-ement dual-polarized planar antenna array are shown in Fig.12.The bandwidth achieved for the antenna array is about56%(1.63–2.9 GHz).The measured isolation is higher than25dB.The lowered isolation for the antenna array compared to the antenna element is mainly due to the coupling between two adjacent antenna elements for different polarizations[21].

The measured gain values and HPWBs of the array are plotted in Fig.13.The radiation pattern measurement for the array was carried out using a far-?eld antenna measurement system at the No.7Research Institute of Chain Electronics Technology Group Corporation(CETC), Guangzhou,China.The measured gain is about16dBi,slightly lower than the simulated result due to the losses from the power dividers and coaxial lines which were not taken into account in simulation.The HPBW in the x-z plane(or the horizontal plane)of the antenna array

for Fig.11.An8-element dual-polarized planar antenna array:(a)geometry;(b)

prototype.

Fig.12.parameters(,,and)measured for the dual-polar-ized planar antenna

array.

Fig.13.Gain values and HPBWs of the dual-polarized planar antenna array. each polarization is within.Fig.14displays the radiation pat-terns simulated and measured for the8-element dual-polarized planar antenna array at1.7,2.2,and2.7GHz.Again only the radiation patterns for polarization are presented due to the geometric symmetry.

Fig.14.Radiation patterns of the dual-polarized planar antenna array simu-lated and measured at(a)1.7GHz,(b)2.2GHz,and(c)2.7GHz.

The simulated and measured radiation patterns are in good agreement. There is no grating lobe and the backside radiation level is about20 dB,suitable for base station applications.

IV.C ONCLUSION

A novel broadband dual-polarized planar antenna has been proposed for2G/3G/LTE base stations.The geometry of the dual-po-larized planar antenna can be decomposed into two perpendicularly crossed bow-tie dipoles.A microstrip stub is introduced to excite each of the two bow-tie dipoles,making the dual-polarized antenna full planar.The dual-polarized planar antenna achieves a bandwidth of about45%(1.7–2.7GHz)with a high isolation better than30dB.An 8-element dual-polarized planar antenna array is developed,which achieves a bandwidth of56%(1.63–2.9GHz).The antenna array yields16-dBi antenna gain and HPBW for each polarization, suitable for base station applications.

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Broadband-spice speedxp sigrity

Boardband SPICE可以导入Touchstone格式或Sigrity BNP格式的网络参数，如散射参数（S，Scattering）、阻抗参数（Z， Impedance）以及导纳参数（Y，Admittance）。这些网络参数可以由测量得到或由全波场求解器如PowerSI得到。Boardband SPICE的输出是智能综合的SPICE等效电路模型，可以在H S p i c e 、P S p i c e 或者其他SPICE兼容的仿真器如Sigrity Speed2000中做直流、交流和瞬态分析。使用 Broadband SPICE： 将网络参数转换成 SPICE等效电路 在SPEED2000， HSPICE或其他时 域仿真工具中使用 PowerSI的结果 提供紧凑的宏模型 简化S参数仿真结 果和测量结果的使 用 改善SPICE仿真的 收敛性 模型转换时具有宽 带的准确性 利用black-box电 路模型增加仿真数 量 在频域和时域中均 支持SSO的分析roadband SPICE是快速准确的实现频域模型到时域模型转换的最有效的桥B 梁。Broadband SPICE可用于建模、仿真和描述RF器件、IC封装、PCB、电缆和接插件等对象。Broadband SPICE可以把一个复杂的网络参数转换为一个紧凑的SPICE等效电路模型，只需要一个按钮就可以完成此操作。得到的电路模型可用于SPEED2000，HSPICE或其他SPICE兼容的仿真工具中。Boardband SPICE的智能综合算法和先进的曲线拟合算法使它能够完成非常复杂的频域S参数的转换。用户可以快速的比较该等效电路模型与初始的S参数模型的响 应以评估模型的精度。局部优化功能可以用于进一步的模型调整。子电路的内部结构和阶数是软件根据网络参数的复杂度自动调节的。Boardband SPICE还内置了严格的无源校验功能，这样时域仿真的收敛性就能得到保证。 输入输出模型准确性Fig1. 生成的SPICE电路模型是根据初始的S参数模型拟合得来的shgzhou@https://www.wendangku.net/doc/ff12544228.html, 周曙光 QQ:772421277

BAS 宽带接入服务器

BAS - 介绍 １．英文缩写: BAS(Broadband Access Server) 中文译名: 宽带接入服务器 分类: 电信设备 解释: 宽带接入服务器（BAS）是一种设置在网络汇聚层的用户接入服务设备，可以智能化地实现用户的汇聚、认证、计费等服务，还可以根据用户的需要，方便地提供多种IP增值业务。出现的原因：在传统的以太网模型中，是不存在所谓的用户计费的概念，要么用户能设置/获取IP地址上网，要么用户就无法上网。IETF的工程师们在秉承窄带拨号上网的运营思路（使用NAS设备终结用户的PPP数据包），制定出了在以太网上传送PPP数据包的协议（Point To Point Protocol Over Ethernet），这个协议出台后，各网络设备制造商也相继推出自已品牌的宽带接入服务器（BAS），它不仅能支持PPPOE协议数据报文的终结，而且还能支持其它许多协议。 ２．制动力辅助系统（BAS）：BAS英文全称为Brake Assist System（制动力辅助系统）。据统计，在紧急情况下有90%的汽车驾驶员踩刹车时缺乏果断，制动辅助系统正是针对这一情况而设计。它可以从驾驶员踩制动踏板的速度中探测到车辆行驶中遇到的情况，当驾驶员在紧急情况下迅速踩制动踏板，但踩踏力又不足时，此系统便会在不到1秒的时间内把制动力增至最大，缩短紧急制动情况下的刹车距离。 3.英文缩写:BAS（Building Automation System） 中文译名：楼宇自动化系统或建筑设备自动化系统 解释：是将建筑物或建筑群内的电力、照明、空调、给排水、消防、运输、保安、车库管理设备或系统，以集中监视、控制和管理为目的而构成的综合系统。楼宇自动化系统通过对建筑（群）的各种设备实施综合自动化监控与管理，为业主和用户提供安全、舒适、便捷高效的工作与生活环境，并使整个系统和其中的各种涉别处在最佳的工作状态，从而保证系统运行的经济性和管理的现代化、信息化和智能化。 4.book and ship 订货与交运（E-Business) 5.biological action spectrum 生物作用光谱 6.Bachelor of administrative studies管理或者商业类别的课程 制动辅助系统(BAS) 基本同EBA。 由于大多数驾驶者在紧急情况下不能迅速而有力地采取制动措施，制动系统的最佳性能不能得到发挥，制动的距离会明显延长。因此，梅赛德斯-奔驰公司研制了制动辅助系统（B AS）。从1997年开始，这个系统成为所有梅赛德斯-奔驰轿车的标准装配。 制动辅助系统（BAS）为有效的制动提供了必要的支持。通过持续地比较踩下刹车踏板的速度，系统就会识别出紧急制动情况。如果驾驶者受惊吓反应踩下制动踏板时速度比在控

broadband-noise

Tutorial:Broadband Noise Modeling Purpose The purpose of this tutorial is to provide guidelines and recommendations for the basic setup and solution procedure for solving an acoustics?eld generated from a sedan car using the broadband noise model.The problem is initially solved for steady state,and then the broadband acoustic model is included in the calculation to perform postprocessing. Prerequisites This tutorial assumes that you are familiar with the user interface,basic setup and solution procedures in FLUENT.This tutorial does not cover mechanics of using the broadband noise model,but focuses on setting up the problem for a sedan car and performing postprocessing. It also assumes that you have a basic understanding of aeroacoustic physics. If you have not used FLUENT before,it would be helpful to?rst review FLUENT6.2User’s Guide and FLUENT6.2Tutorial Guide. Problem Description The problem involves a sedan car model as shown in Figure1.The car is traveling at70 miles per hour.You will study only the acoustics?eld generated by the motion of the car to highlight the noise source on the sedan body,therefore the mirrors and the wheels of the car are ignored. Figure1:The Sedan Car

哈法

Li Conductivity of Nanocrystalline Li Ti O Prepared by a Sol-Gel Method and High-Energy Ball Milling 4512 W. Iwaniak,J. Fritzsche,M. Zukalová,R. Winter,M. Wilkening and P . Heitjans 1,a 1,234 ,1,b 1,c 1Institute of Physical Chemistry and Electrochemistry, Leibniz University Hannover, Callinstr. 3a, 30167 Hannover (Germany) wilkening pci.uni-hannover.de,234b c German Institute of Rubber Technology (DIK), Eupener Str. 33, 30519 Hannover (Germany)J. Heyrovsky Institute of Physical Chemistry, v.v.i.,Academy of Sciences of the Czech Republic,CZ-182 23 Prague 8 (Czech Republic)heitjans pci.uni-hannover.de @@Materials Physics, University of Wales,Aberystwyth, Penglais,Aberystwyth SY23 3BZ (UK)a iwaniak pci.uni-hannover.de,@Keywords:battery materials, lithium titanate, impedance spectroscopy, structural disorder Abstract.Spinel-type structured Li 4+x Ti 5O 12(0 x 3)is actually one of the most promising anode materials for Li ion batteries.In its nanostructured form it is already used in some commerci-ally available Li ion batteries.As was recently shown by our group (Wilkening et al.,Phys.Chem.Chem.Phys.9(2007)1239),Li di ?usivity in microcrystalline Li 4+x Ti 5O 12with x =0is rather slow.In the present contribution the Li conductivity in nanocrystalline samples of the electronic insula-tor Li 4Ti 5O 12prepared by di ?erent routes is investigated using impedance spectroscopy.The mean crystallite size of the samples is about 20nm.The ionic conductivity of nanocrystalline Li 4Ti 5O 12obtained by mechanical treatment is higher by about two orders of magnitude compared to that found for a material which was prepared following a sol-gel method.The latter resembles the behaviour of the microcrystalline sample with an average particle size in the μm range rather than that of a nano-crystalline ball milled one with a mean crystallite size of about than 20nm.The larger conductivity of the ball milled sample is ascribed to a much higher defect density generated when the particle size is reduced mechanically. Introduction High-energy ball milling serves as a versatile tool to reduce and control the particle size of ion con-ducting ceramics [1].Depending on the milling conditions set and the type of mill used to prepare the nanocrystalline samples,after a few hours of milling the crystallite size usually reaches a value of about 20nm [2].The mechanically treated samples are characterized by a large number fraction of interfacial regions which often provide fast di ?usion pathways for the ions.Quite recently,we have shown how mechanical treatment can be used to increase the room temperature Li conductivity of the poor ionic conductor LiTaO 3by about six orders of magnitude [3].An analogous study on LiNbO 3[4,5]has revealed that this enhancement cannot be traced back solely to a size e ?ect.Instead a careful analysis of the microstructure of the materials revealed that structurally perfect,i.e.,less defective nanocrystals,which were prepared by a wet-chemical sol-gel method,do not show this co-lossal enhancement [5].In the previous studies,the Li di ?usivity and conductivity,respectively,was investigated complementarily by 7Li nuclear magnetic resonance (NMR)spin-lattice relaxation and lineshape measurements as well as by impedance spectroscopy. In the present contribution,we draw the readers’attention to the question whether the ?ndings for LiNbO 3are also valid for another nanocrystalline material,viz Li 4Ti 5O 12, which can be easily prepa-

基于模拟乘法器MC1496的混频器设计解读

基于模拟乘法器MC1496的混频器设计

摘要 集成模拟乘法器是继集成运算放大器后最通用的模拟集成电路之一，是一种多用途 的线性集成电路。可用作宽带、抑制载波双边平衡调制器，不需要耦合变压器或调谐电路，还可以作为高性能的SSB乘法检波器，AM调制/解调器、FM解调器、混频器、倍频器、鉴相器等，它与放大器相结合还可以完成许多的数学运算，如乘法、除法、乘方、 开方等。 本设计主要应用集成模拟乘法器MC1496实现以上功能。 模拟乘法器的主要技术指标是工作象限、线性度和馈通度。工作象限是指容许输入 变量的符号范围。只容许ux和uy均为正值的相乘器称为一象限的,而容许ux和uy都可以取正、负值的则称为四象限的。线性度是指相乘器的输出电压uo与输入电压ux(或uy)成线性的程度。馈通度是指两个输入信号中一个为零时，另一个在输出端输出的大小。 混频是将载波为高频的已调信号，不失真地变换为载波为中间的已调信号，必须保持① 调制类型，调制参数不变，即原调制规律不变。②频谱结构不变，各频率分量的相位大小，相互间隔不变。 由于设计和制作增益高,选择性好,工作频率较原载频低的固定中频放大器比较容易,所以采用混频方式可大大提高接收机的性能。此设计就是利用仿真软件，采用模拟相乘 器实现混频电路的。 关键词：MATLAB,模拟乘法器，混频电路

DESING OF MIXER BASED ON THE ANALOG MULTIPLIER MC1496 Abstract Aftertheintegrated operational amplifier i n theintegrated analogmultiplier isone of themost common analog integrated circuit, is a kind of multi-purpose linear integrated circuits.Modulato can be used as a broadband, suppressed carrier bilateral balance, don't need coupling transforme detector,AM,FM or tunedcircuit,alsocan be used as a high-performance S SB multiplication demodulator, mixer/modem modulation, frequency multiplier, and phase discriminator, combining division, itwith amplifier can alsodo many mathematical operation,s uch as multiplication, chengfang, root, etc. This designmainly used integrated a nalog multiplier M C1496achieveabove functions. Analog multiplier isthemain technique indexquadrant,linearity and feedthroughwork.Work quadrantrefers to allow the inputvariable symbol scope.Onlyallow both ux and uy positive multiplier iscalled a quadrant,and allow the ux and uy can takethe positive a nd negative is known as the four quadrants.Linearity refers to the multiplication of the input voltage and outp voltage uo ux (or uy) into linear degree.Feed through degree is refers to the two input signals is equal to zero, the other in the size of the output terminal output.Mixing is the carrier for frequencymodulated signal,no distortion for the carrier to transformto the middle of the modulated signal,m ust be kept in(1)modulationtype,modulationparameters are the same, namely the original modulation law remains the same.The phase of each frequency component of the spectrum structure remains the same, (2) the size and the spacing between the same. Due to the design and production of high gain, good selectivity, and working frequency was lower than those of the original carrier frequency fixed intermediate frequency amplifier is easy, so mixing method can greatly improve the performanceof the receiver.This designisthe use of simulation software, using analog multiplier to realize mixing circuit.. Key words:MA TLAB, Analog multiplier, mixing circuit

MCN推出新一代海事宽带业务FBB

MCN推出新一代海事宽带业务（FleetBroadband） 全速驶向宽带通信的未来 FleetBroadband 是全球第一个通过一个根型天线，同时提供具有成本效益的宽带数据和语音服务的海上通信服务系统。 海上生活非常艰苦。日益增长的商务需求意味着不管您的船位于何处，加强与外界的联系都是最基本的需要。除了导航之外，船长还负有许多其它责任，包括天气信息的更新、路线的规划和订购的补给，为了保持员工的士气，还需要让船员能够和家人通话、发送电子邮件、或上网浏览最新的足球比赛结果。而最重要的是，您需要严格地控制成本。 FleetBroadband 能够给您动力，让您正面应对这些挑战。MCN提供的新一代海事宽带业务引领您的船只进入IP 时代。倘若您还没有为此做好准备，FleetBroadband 仍然支持我们现有海事服务的核心语音和ISDN 数据功能。 FleetBroadband 基于3G 标准，在全球范围内提供连续、同步的语音和高速数据接入服务。您可以收发带有大容量附件的电子邮件、轻松运行复杂的数据应用程序，同时还可以进行语音通话，这将比以往任何时候都更经济方便。终端设备的安装快捷而简便，它已经过测试和验证，符合海事卫星的严格标准，完全值得您信赖。 不论什么类型和尺寸的船只，FleetBroadband 都会为您提供一套可轻松应用的简捷的解决方案。无论您的船位于什么位置，或当时的海上条件如何，FleetBroadband 都将提供最佳接入。 提高运作效率，带来商业领先优势

出众的性能 FleetBroadband 为您提供更快、更具成本效益的数据连接服务。除了连续、实时的天气和ECDIS（电子海图显示和信息系统）更新外，您还可以放心使用更为复杂的应用程序。它的同步语音和数据能力意味着运营系统可以在线运行，同时仍能使用电子邮件、您的内联网及进行语音呼叫，所有这些都通过单一终端完成。因此，在船员与家人通话或发送电子邮件时，船长仍可继续管理船只。 全球覆盖 无论您在何处航行，FleetBroadband都确保您不会失去联络。该服务在全球范围内皆可使用，除南北两极地区之外。 无可比拟的可靠性 无论遇到什么天气，海事卫星都是您值得信赖的好伙伴。我们提供业内最稳健的通信连接，网络的平均可用性超过99.99%。FleetBroadband 终端针对海上使用环境特别设计，并已严格按照我们的高标准完成测试。整套系统由我们的全球合作伙伴网络提供支持。 简便的安装及网络整合 FleetBroadband 可在您的整个船队中迅速进行部署，且作为标准的IP服务，实现与总部网络的无缝隙整合。终端会在全球范围内运行，且用户界面将适用于所有制造商的产品标准。 整体灵活性 FleetBroadband 为您的原有应用提供最新的IP 服务支持，还提供传统的电路交换语音和数据服务。您可以根据需求，在标准的IP 服务和确保数据传输速率的服务中进行选择，它可根据您的应用选择速率。我们可提供三种类型的终端设备，它们通过标准硬件提供不同的性能。 成本效益 拥有FleetBroadband，优异性能及灵活性不再意味着高昂的价格。通话时间定价方案将最适合您的需要，终端成本也相应降低。且您无需签订冗长的合同。它使您能够更便捷地获取全球语音和宽带数据服务，并大大提高运营效率，同时减少船员的通信成本。 绝对安全 海事卫星在向军队、政府及跨国企业提供安全通信方面拥有丰富的经验。如有需要，我们的网络能够支持其它安全产品，如VPN 和ISDN 加密。 增强的接入能力，全球宽带移动办公室 标准IP: 通过安全VPN 连接访问电子邮件、互联网和内联网，在共享频道上速率最高可达432kbps。 流媒体IP: 确保最高达256kbps 的数据传输速率。根据您的应用情况选择数据传输速率。

计算机网络名词英文缩写解释大全

计算机网络名词英文缩写解释大全 AAL ATM适配层ATM Adaptation Layer ABR可用比特率Available Bit Rate ACR 衰减串扰比ACL访问控制列表Access Control List AIPS应用入侵防护系统application intrusion prevention system ADPCM 自适应差分PCM ADSL 非对称数字环路Asymmetric Digital Subscriber Line APON无源光纤网络AMI ATM Management Interface ARP地址解析协议Address Resolution Protocol AMPS先进型移动电话系统Advanced Mobile Phone System AS 自制系统Autonomous System ANS高级网络与服务Advanced Networks and Services ARQ自动重发请求Automatic Repeat Request ANSI美国国家标准协会American National Standard Institute ASIC 专用集成电路Application Specific Integrated Circuit(Chip) ASN.1 抽象语法符号一Abstract Syntax Notation One A TD 异步时分复用Asynchronous Time Division ATM 异步传输模式Asynchronous Transfer Mode BBS电子公告板Bulletin Board System BER 误比特率bit error rate BGP 边界网关协议Border Gateway Protocol B-ISDN 宽带综合业务数字网Broadband Integrated Services Digital Network BICMOS 双极型CMOS BMI脑机接口Bus-Memory Interface BPDU网桥协议数据单元Bridge Protocol Data Unit BOOTP 引导协议BOOTstrapping Protocol BRI 单一ISDN基本速率BUS 广播和未知服务器Broadcast/Unknown Server CAC连接接纳控制Connection Admission Control CATV 公用天线电视CAM可编址内容存储器Content-Addressable Memory CBDS 无连接宽带数据服务CBR 连续比特率Continuous Bit Rate CCITT 国际电话电报咨询委员会CDM 码分复用Code Division Multiplexin CDMA码分多址Code Division Multiple Access CDPD蜂窝数字分组数据Cellular Digital Packet Data | CDV信元延时变化Cell Delay Variatio CEC加拿大教育中心Common Equipment Card CERNET 中国教育科研网The China Education and Research Network CHAP询问握手认证协议Challenge Handshake Authentication Protocol CIDR 无类型域间路由Classless InterDomain Routing CMIP通用管理信息协议Common Management Information Protocol CMIS/CMIP 通用管理信息服务the Common Management Information Service/Protocol CMOS 互补型金属氧化物半导体 CMOT 基于TCP/IP的公共管理信息服务与协议CMIS/CMIP on TCP/IP CNOM 网络营运与管理专业委员会Committee of Network Operation and Management CORBA 公共对象请求代理结构Common Object Request Broker Architecture CPAN Perl档案网络综合\Comprehensive Perl archieve Network CPE\用户端设备\Customer Premises Equipment CPCS\公共部分会聚子层\Common Part Convergence Sublayer CRC循环冗余码校验Cyclical Redundancy Check CS 会聚子层Convergence Sublayer CSM客户服务管理Customer Service Management CSDN 电路交换数据网 CSMA/CD 载波侦听多路访问/冲突检测Carrier Sense Multi-Access/Collision Detection CVE公共漏洞和暴露Common Vulnerabilities & Exposures DAC 双重附上选矿厂Dual Attach Concentrator DAS双重附上站Dual Attach Station DCD检测数据载体Data Carrier Detect DCE数据电路端接设备Digital Circuit-terminating Equipment DES数据加密标准Data Encryption Standard

BRAS-带宽远程接入服务器-原理-作用等

BRAS宽带远程接入服务器 是面向宽带网络应用的新型接入网关，它位于骨干网的边缘层，可以完成用户带宽的IP/ATM 网的数据接入（目前接入手段主要基于xDSL/Cable Modem/高速以太网技术（LAN）/无线宽带数据接入(WLAN)等），起到连接DSLAM等接入层设备与骨干网的作用。实现构建企业内部Intranet、支持ISP向用户批发业务等应用。 主要完成两方面功能，一是网络承载功能：负责终结用户的PPPoE（Point-to-Point Potocol Over Ethernet,是一种以太网上传送PPPPoint to Point Protocol 会话的方式）连接、汇聚用户的流量功能；二是控制实现功能：与认证系统、计费系统和客户管理系统及服务策略控制系统相配合实现用户接入的认证、计费和管理功能； BRAS在网络中的位置及作用 BRAS的产生 BRAS产生的背景 DSLAM是Digital Subscriber Line Access Multiplexer的简称，中文称呼数字用户线路接入复用器。DSLAM是各种DSL系统的局端设备，属于最后一公里接入设备（the last mile），其功能是接纳所有的DSL线路，汇聚流量，相当于一个二层交换机。 由于BRAS可以提供用户认证，授权，计费等多种功能，因此BRAS得以产生

BRAS的主要作用 ?BRAS即Broadband Remote Access Server，宽带远程接入服务器 ?它是一种面向宽带网络应用的新型接入网关。 ?它是宽带接入网与骨干网之间的桥梁，提供基本的接入手段和宽带接入网的管理功 能 ●负责终结用户的PPPoE连接、汇聚用户的流量 ●与认证系统、计费系统、客户管理系统、服务策略控制系统相配合，实现用 户接入的认证、计费和管理功能 ?它位于网络的边缘，提供宽带接入服务、实现多种业务的汇聚与转发，能满足不同 用户对传输容量和带宽利用率的要求，是宽带用户接入的核心设备。 BRAS是宽带城域网中的重要设备之一。BRAS在城域网中的定位和使用使城域网真正得以成为可运营、可管理的智能化网络。BRAS产生之初是DSLAM与骨干网之间没有办法很好地衔接，但目前BRAS已经成为可支持ADSL、CTMS、LAN、无线接入、

宽带接入服务器(BRAS)

宽带接入服务器（BRAS） 简介 英文缩写: BRAS (Broadband Remote Access Server) 中文译名: 宽带远程接入服务器 分类: 电信设备 编辑本段解释 宽带接入服务器（Broadband Remote Access Server,简称BRAS）是面向宽带网络应用的新型接入网关，它位于骨干网的边缘层，可以完成用户带宽的IP/ATM网的数据接入（目前接入手段主要基于xDSL/Cable Modem/高速以太网技术（LAN）/无线宽带数据接入(WLAN)等），实现商业楼宇及小区住户的宽带上网、基于IPSec（IP Security Protocol）的IP VPN 服务、构建企业内部Intranet、支持ISP向用户批发业务等应用。 编辑本段功能 宽带接入服务器（BRAS）主要完成两方面功能，一是网络承载功能：负责终结用户的PPPoE（Point-to-Point Potocol Over Ethernet,是一种以太网上传送PPP会话的方式）连接、汇聚用户的流量功能；二是控制实现功能：与认证系统、计费系统和客户管理系统及服务策略控制系统相配合实现用户接入的认证、计费和管理功能； 一种面向宽带网络应用的新型接入网关。它是宽带接入网的骨干网之间的桥梁，提供基本的接入手段和宽带接入网的管理功能。它位于网络的

边缘，提供宽带接入服务、实现多种业务的汇聚与转发，能满足不同用户对传输容量和带宽利用率的要求，因此是宽带用户接入的核心设备。 目前国内高校局域网中也有采用bras服务的高校，例如南京市东南大学，东南大学提供两种bras接入服务，@a帐号每月免费流量20G，@b 帐号每月免费流量2G。前段时间，南京大学也采用了bras接入服务，每月免费流量1G，超过1G的部分，价格为6元/G，上网收费之高居全国高校之首。目前南京大学已经开始调整网络收费，仿效兄弟学校采用按时收费，每月前30小时免费，超过30小时部分，按每小时0.20元计费，每月20元封顶。高校采用BRAS已经成为一种趋势。 发展阶段 BRAS（Broadband Remote Access Server，宽带远程接入服务器）是用来完成各种宽带接入方式的宽带网络用户的接入、认证、计费、控制、管理的网络设备，是宽带网络可运营、可管理的基石。什么是IP BRAS？采取高端路由器IP内核架构，拥有超过50G的大容量交换矩阵，IP Packet 方式的无阻塞交换，在I/O接口板可运行非IP协议，主要运行IP协议系统软件的电信级BRAS，可称为IP BRAS。BRAS自1999年开始应用，其演进的形态有明显的三个阶段： 第一代：ATM内核BRAS 第一代BRAS主要是用来将ADSL用户接入IP网络发展起来的，由于ATM及其延伸技术ADSL的计费能力非常弱，不得以叠加了BRAS这样的网关计费设备，用户通过PPPoA或PPPoE的模拟窄带拨号方式进行时长或流量等计费方式，ADSL用户到Internet均需要通过BRAS这个ATM-IP