电调微波带通滤波器的研究进展

电调滤波器是当前微波滤波器的研究热点,它们取代滤波器组可减小整机体积和降低设计复杂度。本文从电调滤波器的分类着手,分别综述变容管电调滤波器、铁电薄膜电调滤波器、微机电系统(MEMS)电调滤波器和压电换能器电调滤波器的结构和性能,并分析各自的特点。最后,提出电调滤波器的发展趋势。     

基于GaAs变容二极管的电调滤波器芯片设计

介绍基于GaAs变容二极管工艺的电调滤波器芯片的研究与设计,包括变容材料制备、二极管模型建立以及电路设计。设计数款电调滤波器,工作频段范围覆盖1~19 GHz。测试结果显示,电调滤波器具有超过一个倍频程的调谐范围,器件击穿电压大于+30 V。本文选取中心频率为2~5 GHz可调的一款电调滤波器进行详细介绍,控制电压范围为0~15 V,插入损耗在10 dB左右,输入和输出驻波(电压驻波比)均优于1.8。设计的系列化电调滤波器具有一致性高、小型化、低成本和免调试等优势,拥有良好的应用前景。     

压电换能器电调七阶微带滤波器的设计

为了解决电容管电调滤波器插入损耗大的问题,该文设计了一款以压电换能器为电调元件、介质基片为微扰片的七阶平行耦合线电调滤波器。采用高频结构仿真器(HFSS)和先进的设计系统(ADS)对滤波器的结构参数进行联合仿真和优化,分析了滤波器的耦合系数和外部品质因数随微扰片间距变化的关系。将氧化铝陶瓷基板、压电换能器(PET)和微带滤波器组装在一起构成压电换能器电调滤波器,并用网络分析仪测量滤波器在不同直流电压下的S参数。测量结果表明,中心频率调谐范围为4.38~4.78 GHz时,通带的反射损耗大于10 dB, 插入损耗小于1.5 dB,达到了设计要求。     

1.6～30MHz电调滤波器的设计与实现

基于短波通信系统数字化、小型化需求,提出了1.6~30 MHz电调带通滤波器的设计与实现方法。该滤波器采用双极点调谐滤波,变容管并联谐振,用电感进行耦合的线路技术,实现了外部电压控制(电调谐)滤波器频率的要求。采用将滤波器按频率分段设计,波段开关控制信号输入输出,实现了滤波器宽频率范围同步调谐的目的。同时,各分段滤波器设计集成在一块印制板上,滤波器整个体积仅有40 mm×30 mm×8 mm。仿真结果表明,电调滤波器控制简单、调谐方便,性能指标优良,其设计方法可行。对设计完成的实验品进行测试,结果与仿真相吻合,同时进一步验证了数字控制的多样与灵活性。     

带宽恒定的电调带通滤波器

为了减小电调带通滤波器结构的复杂度,该文设计了一种基于阶梯阻抗谐振器的电调滤波器。以变容二极管作为电调元件,贴片电感作为输入、输出耦合元件。采用ADS和HFSS软件分析了耦合系数和外部品质因数随频率的变化关系。仿真结果表明,在0.45～1.0 GHz,耦合系数和外部品质因数保持恒定。采用相对介电常数为2.2的Rogers 5880 (tm)介质基板制作实物,并用网络分析仪进行测试,实测结果与仿真结果基本一致。     

一种C波段大功率电调滤波器设计

针对电调滤波器失谐和控制精度问题,该文提出了一种保持恒定带宽的耦合机构设计方法,论述了应用三维电磁场仿真软件HFSS协同仿真的过程,分析了运动执行机构软硬件的关键技术,设计了一个C波段、大功率(400 W)的电调滤波器。仿真和实测结果表明,在整个调谐频段内该滤波器的带宽恒定,驻波、抑制度和插入损耗等指标稳定良好。     

电调滤波器自动校频技术

传统的电调滤波器一般采用步进电机带动滤波器调谐杆,通过调谐杆的长度变化来实现频率变化,步进电机的驱动脉冲数与滤波器的频率一一对应,即可实现电调滤波器的频率调谐功能。由于电调滤波器是一种机械传动结构,随着腔体、传动、回零、调谐杆以及温度等的变化,脉冲数与频率对应关系变差,导致通信装备使用故障甚至瘫痪。从电调滤波器的工作原理出发,提出了一套电调滤波器自动校频程序,在通信设备中运行该专用程序,即可实现电调滤波器的频率校准与记忆,从而彻底解决电调滤波器的频率偏移问题。     

压电换能器电调介质滤波器的设计与实现

为了解决变容管电调窄带滤波器的插入损耗大和承受功率小的问题,研究了用压电换能器作电调元件的电调介质滤波器.分析了压电换能器调谐介质谐振器的机理,讨论了耦合系数和外部Q值的控制方法,仿真结果表明耦合系数和外部Q值随调谐频率的变化较小.采用HFSS软件设计和优化了两级电调介质滤波器的结构,并用高Q值的介质谐振器制作了两级电调介质滤波器.根据ANSYS软件的分析结果,提出了提高电调率的有效措施.当控制电压为0~50V时,滤波器的中心频率调谐范围为4.155~4.205GHz,3dB带宽为37~40MHz.     

电调滤波器Q值与带宽分析

在甚高频频段,电调滤波器的构成以集中参数元件为主。通常情况下,高频瓷介质电容都有较高的Q值,不会对带宽产生过大的影响,怎样对一个频带够窄的电调滤波器进行设计,电感的Q值起着一定的决定性作用。文章基于电路品质因数(Q值)与匹配带宽之间的理论关系,利用ADS软件对窄带电调滤波器的Q值与带宽进行了仿真分析。     

高三路载波机的設計方法介紹(續)

ii 高通滤波器的设计首先已知通带界限频率为:f′_(el)=63千赫,于是高通滤波器的截止频率为:f′_0=f′_(el)x_(el)=60.598千赫。这里x_(el)是低通滤波器的标称通带界限频率。高通滤波器的阻带界限频率为:     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.     

INTEGRATION OF OPTICAL AND WIRELESS NETWORKS

正For a long time,optical and wireless systems/net-works are developed in separate communities witha few attempts for in-depth convergence.In fact,it prom-ises many advantages to combine the optical and wire-less technologies in the levels of systems and networks.Recently,both academia and industry have made manyefforts to enter a new phase of development to take op-tical and wireless systems as fully integrated networks.To provide high bandwidth and reliable service for bothfixed and mobile users,a well-designed network must     

社长序言（英文）

正Happy New Year!As we step into a new year,we take a look back at the key feature topics covered in China Communications over the past 12 months and set out our expecta-     

云计算专题（英文）

正Cloud computing is a novel computing paradigm that utilizes remote cloud resources to achieve a high-performance computation.Cloud provides infrastructure,platform and software as different on-demand services.China has made remarkable progress in cloudbased products and operating system technology.The government,enterprises and research institutions are all active in the development of cloud computing-related projects.Despite the progress,many important problems     

Call for Papers—Feature Topic,Vol.12,No.3,2015

正Smart Grid Communications The electric power industry is undergoing profound changes as the industry aims to capture the promise of a smart grid for a sustainable energy future.Enabled by the advanced sensing devices such as Phasor Measurement Units(PMUs),increasingly powerful