Ba(B'1/3 Ta2/3)O3微波介质陶瓷的研究进展

微波介质陶瓷是制作微波器件的关键材料。具有复合钙钛矿结构的Ba(B'_1/3 Ta_2/3)O₃(B'=Mg、Zn)型微波介质陶瓷在微波毫米波频率下具有较高的品质因数,是现代微波通信技术中被广泛应用的微波陶瓷材料。文中介绍了近年来此类微波介质陶瓷的发展与研究现状。     

Ca-B-Si掺杂对Ba(Mg_(1/3)Nb_(2/3))O_3陶瓷介电性能的影响

采用传统电子陶瓷工艺合成了Ca-B-Si(CBS)玻璃掺杂的Ba(Mgl/3Nb2/3)O3微波介质陶瓷,研究了CBS掺杂量对陶瓷微波介电性能的影响。结果表明:CBS掺杂可促进陶瓷烧结并提高B位1:2有序度,进而降低微波介质损耗。当w(CBS)=3%时,陶瓷烧结温度由纯相时的1 500℃以上降至1 250℃,表观密度提高到6.32 g/cm3以上,陶瓷的微波介电性能达到最佳值:εr=26,Q.f=67 800 GHz(8 GHz),τf=25×10–6/℃。该陶瓷有望成为用于高频段微波器件的材料。     

陶瓷绝缘子的测试与改进

金属墙镶嵌氧化铝陶瓷绝缘子是微波毫米波芯片广泛运用的一种封装外壳形式,而绝缘子则是封装外壳的关键组成部分,它连接了封装外壳内的器件和外部的模块,所以它的特性直接影响所封装器件或模块的微波性能。文章通过对一种现有的镶嵌类封装外壳的陶瓷绝缘子利用电磁场仿真软件HFSS进行微波S参数仿真设计、用普通高温共烧陶瓷（HTCC）工艺加工后,进行测试及改进,减小了陶瓷绝缘子的微波传输损耗和驻波比,从而提高了外壳使用截止频率。     

微波陶瓷及其应用

为了开发合适的微波介质材料,已经仔细地研究了许多种陶瓷.近来在研究具有高Q值的微波陶瓷方面已取得了明显的进展.本文概括地评述了当前微波陶瓷的研究情况以及介质谐振器在微波器件中的应用.     

低烧ZnO-TiO2微波陶瓷介电特性及片式多层带通滤波器研究

采用材料特性、器件设计及制备工艺相结合的三位一体研究模式,研究了低烧ZnO-TiO2微波陶瓷介电特性,利用高频结构仿真软件HFSS对低烧陶瓷带通滤波器微波特性进行建模,重点介绍材料介电特性对片式带通滤波器性能影响的优化仿真,采用LTCC制造工艺技术制备片式多层带通陶瓷滤波器。研究结果表明:ZnO-TiO2微波陶瓷在895~910℃烧结,陶瓷相ZnTiO3、TiO2稳定存在,具有较佳的微波介质特性,在900℃烧结3h,其介电性能:εr=27.05、Qf=19822GHz、τf=2ppm/℃,该材料与Ag电极能较好匹配。模拟仿真表明:低烧材料的相对介电常数偏差是器件设计制备中的关键要素,仿真优化结果与LTCC试验样品的测试结果吻合较好。制备出的片式多层带通滤波器适用于表面贴装技术。     

国外陶瓷-金属封接工艺动态

一、概述随着通讯、火箭、人造卫星、宇宙探测及粒子加速器等技术的飞速发展,对微波电子管也提出了许多新的或更高的要求。在微波电真空器件中,由于陶瓷-金属结构比起玻璃-金属结构无论在性能上或可靠性上都优越得多,因此目前微波管已大量采用了陶瓷-金属结构。正因为如此,陶瓷-金属封接工艺就成了微波管制造工艺中的关键工艺之一了。六十年代中期以来,国外在电真空器件中大量采用的陶瓷-金属封接工艺仍然是烧结金属粉末法(以Mo-Mn金属化法为主)和活性金     

低固有烧结温度LTCC微波介质陶瓷研究进展

为了满足现代微波通信器件小型化和集成化发展的要求,必须开发出烧结温度低且能与Ag、Cu等价廉金属电极实现共烧兼容的微波介质陶瓷体系。重点介绍了Li基、Bi基、钨酸盐、磷酸盐和碲酸盐等低固有烧结温度的微波介质陶瓷体系,并总结了其在低温共烧陶瓷方面的研究进展。     

用于微波组件的LTCC 3 dB耦合器

低温共烧陶瓷(LTCC)技术是实现机载、星载、舰载相控阵雷达小型化、轻量化、高性能、高可靠、低成本的有效手段。文中论述了LTCC技术在微波集成器件应用中所具有的技术优势,并介绍了用于微波组件的LTCC 3dB耦合器的构成、关键制造工艺技术以及性能参数等,为LTCC技术在微波集成器件中的应用进行了有益的探索。     

固态微波毫米波器件技术进展

固态微波毫米波半导体材料与器件、固态微波毫米波电路与模块、毫米波与太赫兹技术以及新型固态微波毫米波器件在近年来有很大的发展,在相控阵雷达、电子战、军民用通信领域有广泛的应用前景。当前这些器件应用较为集中于各类T/R组件。文章按固态微波毫米波半导体材料与器件、固态微波毫米波电路与模块、毫米波与太赫兹技术以及新型固态微波毫米波器件的顺序,概要介绍了固态微波毫米波技术的新进展。     

LTCC基片的飞针测试工艺研究

低温共烧陶瓷技术(Low Temperature Co-fired Ceramic LTCC)是近年来兴起的一种相当令人瞩目的多学科交叉的整合组件技术,广泛用于基板、封装及微波器件等领域。主要介绍当前广泛用于检测混合电路板、LTCC陶瓷基板、PCB裸板故障的飞针测试设备在陶瓷基片测试中的工艺研究。     

Do we really need ferroelectrics in paraelectric phase only inelectrically controlled microwave devices?

Typical paraelectric materials (e.g., SrTiO₃, KTaO₃, Ba_xSr_1-xTiO₃, x<0.5) and electrically tunable microwave devices based on these materials are briefly reviewed. The analysis shows that in spite of the recent year's extensive efforts, no considerable improvement in the microwave losses in thin paraelectric films has been achieved. Thin films, regardless of fabrication method and substrate type, have much lower dielectric permittivity than bulk single crystals, and the loss tangent at microwave frequencies (f>10 GHz) is of the order of 0.01 (at zero dc-bias field) at room temperature. Nevertheless, quite promising component and subsystem level devices are successfully demonstrated. Use of ceramic (bulk and thick film) ferroelectrics in tunable microwave devices, currently considered for industrial applications, offer cost reduction. In this paper, explicitly for the first time, we consider possibilities and benefits of using ferroelectrics in polar phase in electrically controllable microwave devices. Examples of using ferroelectrics in polar state (e.g., Na_0.5K_0.5NbO₃, SrTiO₃ in antiferroelectric phase) in electrically tunable devices are reported     

A behavioral model development methodology for microwave components and integration in VHDL-AMS

The new generation of system-on-chip (SoC) incorporates digital, analogue, radiofrequency (RF)/microwave and mixed-signal components. Therefore, novel design methodologies must be developed to direct the design of these mixed-technology systems, which will have to include accurate behavioral libraries of devices and processes. Thus, this paper describes a behavioral modeling approach which generates accurate empirical models for RF/microwave devices and that can be easily integrated into a VHDL-AMS simulator. This approach is applied to a microwave tunable phase shifter and it is illustrated by the development of a VHDL-AMS model library for RF/microwave applications.     

Microstrip Transmission On Semiconductor Dielectrics

As a result of both a larger number of microwave functions performed by semiconductor devices and a larger number of functions required in modern systems, it has become highly desirable from both the system and the device standpoint to fabricate multiple microwave semiconductor devices on a common substrate. The use of multiple devices in a single package has system and reliability advantages, but there is also offered the possibility of improved performance of the microwave components. This results from the elimination of packaging of each individual element and the ability to place the package interface in a more advantageous position in the circuit. To effect such an improvement, an efficient means of microwave interconnection must be available. The interconnections must have not only low dissipative losses through the microwave region, but be capable of providing the impedances necessary for transformations by the various microwave functions and for circuit resonating elements. The range of impedance commonly required is of the order of 20 /spl Omega/ to 80/spl Omega/. To be compatible with semiconductor materials and processing, the choice of dielectric material was limited to film dielectrics, possibly SiO/sub 2/, or the use of the semiconductor material itself as a dielectric. For both semi-insulating gallium arsenide and silicon of resistivity greater than 1000 /spl Omega/-cm, the loss is sufficiently low to perform efficient interconnection of devices on a common substrate and is considered even suitable for other components such as directional couplers and hybrids where extremely high Q is not required.     

Dielectric materials, devices, and circuits

Dielectric materials are continuing to play a very important role in the microwave communication systems. These materials are key in realization of low-loss temperature-stable resonators and filters for satellite and broadcasting equipment, and in many other microwave devices. High dielectric-constant materials are critical to the miniaturization of wireless systems, both for the terminals and base-stations, as well as for handsets. In this paper, a sequential evolution of the dielectric materials applications in microwave devices will be reviewed. This includes dielectric waveguides, low-loss temperature-stable ceramic materials, dielectric resonators, and filters. The recent advances in the multilayer circuit modules, dielectric antennas, and ferroelectrics are also described     

陶瓷外壳内部气氛和多余物对产品性能的影响

陶瓷外壳内部气氛、多余物对器件会造成致命的影响。陶瓷外壳封装芯片后,其内部残余气氛的状况对元器件的性能、寿命和可靠性影响很大,很容易造成元器件的性能低劣和早期失效。陶瓷外壳多余物,即便是非导电多余物,对元器件也会造成影响,可导致光电器件信号传递和继电器触点的不导通。文章通过分析陶瓷外壳内部残余气氛对元器件的影响及影响因素,陶瓷外壳烧结过程、电镀过程造成的水汽及解决办法,陶瓷外壳多余物对元器件的影响等,指出了解决问题的方向和办法,对提高产品质量有一定的意义。     

镁橄榄石瓷的烧结工艺

主要对微波管用镁橄榄石瓷进行工艺研究.通过试验对其烧结温度进行了分析,找出最佳烧结温度范围.试验结果表明:配方组成与烧结温度是镁橄榄瓷制备的关键因素.     

AlN陶瓷的应用及其表面金属化

ＡｌＮ陶瓷由于其优良的导热性能，良好的高频性能及与ＢｅＯ相比无毒性，是一种很有潜力的微波功率器件用材料。ＡｌＮ陶瓷的许多应用都涉及到了陶瓷表面金属化技术及与金属接合技术，本文对ＡｌＮ陶瓷的应用、ＡｌＮ陶瓷表面金属化及其与金属接合技术的现状及发展进行了评述。