带有台阶电极结构和TiN阻挡层的高可靠微波硅功率晶体管

本文描述了一种具有台阶电极结构和ＴｉＮ扩散阻挡层的高可靠微波硅功率晶体管，将这种用于高频大功率器件的结构与传统的平面结构进行了比较讨论，这种新式结构可使微波器件获得更好的性能，由于大功率器件带有梁式引线金属化系统，Ａｕ－Ｓｉ反应及局部铂硅化合物的生长是其主要的失效机理，为了减少上述缺陷，Ｔｉ层必须加厚。同时，进一步讨论了ＴｉＮ在梁式引线金属化系统中的应用，高温长期工作实验结果证明，将台阶式电极结构     

93全国微波会议胜利闭幕

93全国微波会议于十月二十五至卅日在合肥市举行。中国电子学会微波分会与IEEE MTT—S Beijing Chapter主席林为干教授主持了会议。会议共录用论文293篇,涉及到近二年来微波电磁理论、微波天线、微波有源器件与电路、微波无源器件与电路、微波系统及应用、微波测量、微波CAD、微波网络理论、毫米波技术、微波与交义学科十个方面的工作和发展动向,同时举办了相当规模的微波产品展示会。出席人数400余人、安微省和台肥市有关领导出席了开幕式。这又是一次微波界的盛会。     

InP基器件与电路的应用备受瞩目

本文概述InP基HEMT与HBT器件与电路，在微波与毫米微波范围由于低噪声．功率应用的优越性能。而Inp基器件与电路在高速光通信和高频无线通信领域日趋成熟，备受瞩目。     

基于左手材料的超宽带平面天线的设计

设计了一种十字交叉耦合型结构的左手材料,左手材料构成的超宽带陷波滤波器通带范围为3.16~11.84GHz,陷波范围为7.01~8.56GHz。针对现有平面天线设计难、体积大和滤波性能低等问题,将左手材料的滤波器加载于两款结构简单、易于加工的平面天线上,构成基于左手材料的超宽带滤波天线。相比于现有平面天线,该滤波天线同时具有辐射和滤波功能。经HFSS软件仿真和计算得出该滤波天线工作在超宽带范围内,X波段陷波处回波损耗可达-1.30dB,实现了超宽带天线集成化、小型化的设计。     

左手结构及其在天线微波领域中的应用

左手材料因其具有介电常数和磁导率同时为负值的电磁特性,近年来得到科学界的广泛关注。基于微带线等传输线结构所构成的左手材料与传统右手材料相比传输相移特性亦有不同,因此在天线微波系统中具有很大的应用潜力。文中介绍了这类左手传输结构的基本设计理论和性能特点,并对其在未来天线微波领域中的应用进行了探讨。     

横向加速度传感器设计及特性研究

一般微机械加工的梁──岛结构加速度传感器，梁的平面都是与器件平面平行的，因此只能测量器件平面法向的加速度分量．我们提出了一种制作梁平面与器件平面相垂直的梁──岛结构的微机械加工方法，并用以设计和制造了一种可测量平行于器件平面的加速度分量的横向加速度传感器，为研制三维加速度传感器提供了新思路．     

碲镉汞双色红外焦平面读出电路研究进展

介绍了碲镉汞(MCT)双色红外焦平面探测器的研制背景,及美、英、法等西方发达国家的发展现状。从读出电路(ROIC)设计角度出发,重点阐述了上述3个发达国家的碲镉汞双色焦平面器件结构类型和相应读出电路设计特点。最后介绍了国内昆明物理研究所在碲镉汞双色焦平面读出电路研究方面取得的进展。昆明物理研究所研制出两种碲镉汞双色焦平面读出电路,一种是适用于双铟柱半平面器件结构的128×128双色信号同步积分读出电路,另外一种是适用于单铟柱叠层器件结构的640×512双色信号TDMI(时分多路积分)读出电路。两种读出电路芯片在77 K条件下正常工作,主要功能及性能指标与国外同类产品相当。     

国内外几种衰减材料的制造工艺及结构性能比较

在电真空器件中广泛使用吸收微波的材料，随着器件功率增大，对此种材料的要求也越来越高，本文讨论了几种国外微波衰减瓷材料在结构性能和制造方面的特点，以及与几种国产衰减瓷材料的比较，对衰减瓷材料提出了主要要求；叙述了表征吸收微波电磁能量的参数和制造材料的物化原理。     

多通带复合左右手传输线的设计与仿真

提出一种具有两组复合左右手通带的平面传输线结构.与传统左手微带线相比,本结构利用连有金属折线的矩形贴片和接地板上T形DGS(defected ground structures)结构形成一组新的左手通带和右手通带.为了使左右手通带间禁带闭合,用梯形贴片及接地板上交趾DGS结构代替上述结构,最终实现具有两个零级谐振频率点的平面传输线.结构的仿真结果与利用等效电路和Bloch-Floquet原理得到的理论结果及测量结构都符合较好.这种新颖的具有多通带的复合左右手传输线可应用于多通带微波器件设计.     

新型结构左手材料的仿真设计与实现

左手材料通过其特殊的结构阵列来实现负的介电常数和磁导率,将之应用到天线罩、滤波器和天线等方面,可以较好地改善特性。2种新型左手材料结构被提出,分别是史密斯方形环的简化形式和P型结构,其中P型结构又包含基本形式与改进形式。针对这2种模型,利用仿真软件进行了仿真设计,发现这2种形式可以在4～6 GHz频段实现负的介电常数和磁导率,其中P型结构实现效果更好。     

Compact meta-material transmission line balun based on meander lines structure and MEMS technology

This paper presents a novel compact meta-structure microstrip balun, which is characterized by left-handed properties. In the novel structure, two coupled meander lines are used to generate series capacitor and series inductor. Compared with conventional composite right/left-handed transmission-line structures, the new structure has smaller size and is easily fabricated by MEMS (Micro Electromechanical Systems) technology. Using such a meta-structure, a wide band microstrip balun is designed and fabricated. Good performance in phase error in wide pass band has been achieved.     

CRLH-TL引领未来多频带小型化低损耗传输新变革

文章从左右手复合传输线(CRLH-TL)的机理出发,以传输特性为依据,阐述了其与传统平面传输线的相位响应区别,揭示了构成的左手传输线(LH-TL)的正向非线性及右手传输线(RH-TL)的负向线性传输特性导致的任意两个频率下四分之波长独特的响应及任意一个频率下的零度响应特征。根据这一原理,论证了不同于传统CRLH-TL而体现高选择性的T形双频带传输线和高设计灵活性的多频带传输网络的优越特性。上述不同结构的传输线分别应用于双频带威尔金森功分器和三频带的吉赛尔功分器两种无源器件的设计,证实了CRLH-TL具有实现多频带、小型化、低损耗传输的优异特性,为CRLH-TL引领未来小型化低损耗传输新变革提供了强有力的理论及实验依据。     

基于人工表面等离激元的天线研究进展

人工表面等离激元是在人工电磁媒质与传统材料界面激发的一种亚波长表面电磁模式, 具有波长短、场局域增强、色散可调等新奇的电磁特性, 在小型化微波器件、隐身材料与隐身结构、天线/天线罩等领域具有重要应用前景.文章综述了人工表面等离激元在天线中的应用研究进展, 包括基于混合模式耦合、相位梯度超表面解耦、周期结构解耦等原理的端射天线、多波束天线、频扫天线, 为新型天线的研发与应用提供技术支撑.     

一种频带展宽的小型化左手偶极子天线的设计

左手传输线加载偶极子(简称左手偶极子)可以有效实现天线的小型化,但是这种天线通常带宽窄、效率低。通过采用一种渐变的梯形网络结构代替传统的非渐变的结构形式来改善天线的阻抗特性,设计了四单元的左手偶极子天线,进而拓展了天线的带宽,天线总长度为0.2。仿真和实物测试结果显示:天线同时工作在–1阶和–3阶谐振模式,|S11|≤–10 dB的阻抗带宽达到6.5%,在工作频段内(571~610 MHz),天线的增益不小于–4.25 dBi,效率大于25%。     

新型左手传输线馈电微带阵列天线

提出了一种采用复合左右手传输线馈电的新型微带阵列天线.该天线利用左手传输线的相位超前特性来补偿传统的右手传输线所具有的相位滞后,从而保证了天线单元之间的同相位馈电,避免了因相位延迟导致的天线波束偏移,并进一步提高了天线的增益.仿真与实际测试证明:与同类型天线相比,该天线具有尺寸小、频带宽和馈电网络设计简单等优点,可在微波系统中实际使用.     

Design and Analysis of Super-Wide Bandpass Filters Using a Novel Compact Meta-Structure

This paper presents a novel compact meta-structure, which is characterized by left-handed properties. In the novel structure, two linear arrays of metallic vias and short-stub inductors are used to generate shunt inductors besides the series interdigital capacitors. Compared with conventional composite right/left-handed transmission-line structures, the new structure has weaker coupling to other components and is easily controlled by adjusting the shunt inductance and series capacitance to produce different left-handed properties. Due to the isolation of two via arrays, the proposed structure can also be transplanted directly from the microstrip system to the coplanar-waveguide system. We have proposed an efficient procedure to retrieve the equivalent propagating modes for both forward and backward waves based on the matrix pencil method, which provides an easy way to study the propagation characteristics. Using such a meta-structure, a series of super-wide bandpass filters are designed and fabricated at different frequency bands. Good agreements between simulation and experiment results have been achieved, and good performance in passbands and stopbands has been observed with a relative 3-dB bandwidth larger than 70%. For easy design of such super-wide bandpass filters, an experienced formula is given between the physical size and the center frequency of the 3-dB passband, which can be used to redesign any filters at other frequency bands     

New Proximity Coupled Feeding Method for Reconfigurable Circularly Polarized Microstrip Ring Antennas

A new simple single-feed method for circularly polarized ring antennas has been investigated. Experimental and theoretical investigation show that either right-handed (RH) or left-handed (LP) circular polarization (CP) can be easily achieved by selecting one of the two input ports of the antennas. The proposed U-shaped microstrip feed line excites the fundamental ${rm TM}_{11}$ mode of the ring radiating elements through proximity coupling along the semi-annular section of the line. The induced rotating surface currents on the ring radiators contribute to the circular polarization behavior of the antennas. Two types of rings have been investigated. Square ring prototypes operate at 2.7 GHz have been designed, fabricated and evaluated to show the basic operating principles of the antennas, while annular ring radiating elements operate at 2.255 GHz are realized to demonstrate the reconfigurable capability of the new feeding structure. In the reconfigurable design, a high isolation RF switch is used to direct the input signal between the two input ports. With suitable biasing arrangement of the RF switch, the antenna is capable to radiate at either types of circular polarization. The reconfigurable design is fed by a single microstrip line. Return losses, axial ratios, gains and radiation patterns of the prototype antennas have been measured for verifications. A parametric study of the new feeding structures with a square ring has been carried out for important design guidelines.      

CAD of waveguide array antennas based on "Filter" concepts

In this paper, an alternative approach for the design of open-ended waveguide array antennas is presented. The approach is based on microwave filter concepts. The exploitation of this alternative viewpoint has been made possible by the availability of a very efficient computer-aided design (CAD) tool which is based on a full-wave modal analysis technique. In this paper, we first outline the technique for the efficient analysis of open-ended waveguide array antennas. Using the software developed and following the alternative design approach, two different application examples are then shown, indicating how the alternative viewpoint introduced gives indeed significant additional degrees of freedom.     

左手媒质的阻抗边界条件

从Maxwell方程出发，研究了平面波入射到空气和左手媒质的分界面上时，界面附近的电磁场，并将电场和磁场的关系表示为阻抗边界条件表达式，然后与右手媒质的阻抗边界条件进行对比，指出其形式上的统一和计算公式的区别。在此基础上，对多层媒质引用传输线法进行分析，并采用其给出的多层媒质的反射系数计算公式，计算了多层媒质内包含左手媒质时的表面反射系数，并对多层媒质包含左手媒质和右手媒质的情形进行了对比，研究了其反射系数幅度和相位的异同。最后将边界条件应用到阻抗半平面的散射场的计算中，探讨了平面波入射到单面涂敷左手媒质的阻抗半平面上时的散射场，并对场的计算公式作了简单分析。