横向耦合谐振滤波器寄生模式抑制的研究

该文应用耦合模理论,重点研究了几个关键因素对横向耦合谐振滤波器高次模式对应旁瓣相对于主通带相对衰减量的影响.这几个关键因素包括相对膜厚、反射栅与换能器周期比、换能器间汇流条宽度等.研究表明,该文在设计频率为159.2 MHz的横向耦合谐振滤波器时,对高次模式引起的旁瓣作了抑制处理,该文给出了此滤波器的计算模拟结果和实验测试数据.实验器件匹配后具有高阻带抑制(通带外抑制达50 dB)、低插损(2.9 dB)和平坦的通带(通带波纹小于0.3 dB),1 dB带宽为130 kHz.     

64°YX-LiNbO3基片上铜短路金属栅的色散特性

利用离散Green函数和有限元等方法对在64°YX-LiNbO3基片上铜短路金属栅阵中漏表面波的传播特性进行了理论研究。给出了不同厚度铜栅条引起的声表面波的色散关系和Coupling-of-Modes耦合模(COM)参数,对其色散特性进行了分析。为研制相应的声表面波器件提供理论支持。     

纵向耦合滤波器组成模块对器件性能影响的研究

通过建立结构的设计数学模型，采用耦合模(COM)理论，研究了纵向耦合低损耗滤波器各个组成模块以及它们对器件性能的相互影响，由此给出了最佳设计纵向耦合低损耗滤波器的方法，并给出了一个具体设计的理论预计和实际制作器件结果比较，验证了研究结果。     

一种w波段器件插损测试的方案分析

w波段器件插损的测试通常采用传输测量方法,该文提出了一种利用反射测量方法测试器件插损的方案,并对这一方案进行了一定的分析。     

超结构光纤Bragg光栅制作模型及其耦合模理论

从衍射光学角度出发，分析了超结构光纤Bragg光栅（SFBG）的制作理论模型，进而采用理想模展开的耦合模理论对SFBG的模场分布进行了分析，给出了SFBG的耦合模方程，并采用数值计算方法对其反射谱进行了计算机模拟。     

大功率微带定向耦合器的设计

介绍了一种S波段25 dB大功率微带定向耦合器的设计方法及测试结果。为了对大功率微波信号进行较为准确的检测,微带耦合器需具有抗大功率串扰强、带内平坦度好、插损小的性能。文中采用电感补偿平衡奇偶模相速技术,由二元概念和容性补偿奇偶模相速的理论,分析出电感补偿电路的设计参数,用Ansoft HFSS软件进行仿真与优化,实现了高性能大功率微带定向耦合器。微带电路加工在Rogers RT/duroid 6002基片上,分别用10 W和300 W固态发射机对其抗大功率串扰的性能进行了测试。经实测数据分析,所设计的耦合器在工作频带内,插损小于0.3 dB,带内波动低于1 dB,方向性大于9 dB。     

采用电容耦合式馈线的高温超导滤波器设计

为了获得结构紧凑的滤波器,在设计中采用了螺旋形谐振器和电容耦合式馈线结构.利用集总元件等效电路给出了谐振器与电容耦合式馈线组成的电路的谐振频率和有载Q值的表达式.提出了馈线为电容耦合式时的集总元件带通滤波器等效电路.并基于上述电路在MgO基片上设计和实际制作了一个高性能的高温超导微带线滤波器.该滤波器的中心频率为2542 MHz,相对带宽为0.6%,尺寸仅为10mm×15mm.测试结果表明滤波器的带内插损小于0.1 dB,反射损耗为40.0 dB,验证了该等效电路设计方法的有效性.     

国外简讯

无调谐低插损漏表面滤波器 在某些应用中需要低插损的SAW滤波器。一般实现低插损的方法是利用多相单向换能器,但是这种方法需要相移网络和多步制作,不易实现。Milsom等人研制的低插损SAW滤波器虽然不需要相移网络,但是其带宽限制在1％以下,而且体积较大,这是因为基片的机电耦合系数不够大。     

光纤光栅最佳切趾函数的研究

采用耦合模理论，给出了用传输矩阵法计算光纤Bragg光栅（FBG）特性的方法，进而得到了在不同切趾函数形式下的FBG反射谱的数值解。通过理论分析，给出了最佳切趾函数反射谱和群时延特性曲线。     

实用平行藕合微帶线电路尺寸综合设计法

本文介绍由平行耦合微带线奇、偶模阻抗设计出厚度不为零的微带线的几何尺寸的一种算法。给出由厚度引起的附加场阻抗近似计算公式,以及用计算机进行综合设计程序流程图。并结合实际应用,绐出了氧化铝陶瓷基片微带线的一些计算结果。附带提及与设计强耦合器件有关的电路制作工艺中的尺寸误差问题。     

可穿戴式柔性触觉传感单元制备及测试

针对触觉传感器存在一定的局限性,提出了一种基于无源无线的柔性触觉传感器,首先利用等离子体与表面活性剂联合修饰工艺提高柔性衬底与金属材料之间的粘附性;其次制备了具有周期性结构的褶皱电极结构;最后以无褶皱的CNTs/PDMS复合材料和有褶皱的电感为力敏敏感单元和输出单元,研制了无源无线振荡传感器结构并进行了手指弯曲测试。测试结果表明：手指在不同弯曲程度时,传感器的信号会发生明显的漂移,证明了其能够初步应用到手指弯曲感应方面。     

Chip-package codesign of a low-power 5-GHz RF front end

Future high-performance wireless communication applications such as wireless local area networks (WLANs) around 5 GHz require low-power and highly integrated transceiver solutions. The integration of the RF front end especially poses a great challenge in these applications, as traditional front-end implementations require a large number of external passive components. In this paper, we present the single-package integration of complete transceivers based on a thin-film multichip module (MCM) technology with integrated passives. The MCM substrate is a a common carrier onto which different ICs are mounted. passive components such as RF bandpass filters, inductors, capacitors, and resistors are directly integrated into the MCM substrate with the use of the multilayer structure of the MCM technology. The “system-on-a-package” approach is illustrated with a voltage-controlled oscillator for Digital European Cordless Telephone (DECT) applications and a 5-GHz WLAN front end. These examples indicate that this approach yields a compact low-power implementation of complete transceivers for high-performance wireless applications     

基于埋置式基板的3D-MCM封装结构的研制

研制一种用于无线传感网的多芯片组件(3D-MCM).采用层压、开槽等工艺获得埋置式高密度多层有机(FR-4)基板,通过板上芯片(COB)、板上倒装芯片(FCOB)、球栅阵列(BGA)等技术,并通过引线键合、倒装焊等多种互连方式将不同类型的半导体芯片三维封装于一种由叠层模块所形成的立体封装结构中;通过封装表层的植球工艺形成与表面组装技术(SMT)兼容的BGA器件输出端子;利用不同熔点焊球实现了工艺兼容的封装体内各级BGA的垂直互连,形成r融合多种互连方式3D-MCM封装结构.埋置式基板的应用解决了BGA与引线键合芯片同面组装情况下芯片封装面高出焊球高度的关键问题.对封装结构的散热特性进行了数值模拟和测试,结果表明组件具有高的热机械可靠性.电学测试结果表明组件实现了电功能,从而满足了无线传感网小型化、高可靠性和低成本的设计要求.     

基于埋置式基板的3D-MCM封装结构的研制

研制一种用于无线传感网的多芯片组件（3D-MCM) . 采用层压、开槽等工艺获得埋置式高密度多层有机（FR-4）基板,通过板上芯片（COB) 、板上倒装芯片（FCOB) 、球栅阵列（BGA）等技术,并通过引线键合、倒装焊等多种互连方式将不同类型的半导体芯片三维封装于一种由叠层模块所形成的立体封装结构中;通过封装表层的植球工艺形成与表面组装技术（SMT）兼容的BGA器件输出端子;利用不同熔点焊球实现了工艺兼容的封装体内各级BGA的垂直互连,形成了融合多种互连方式3D-MCM封装结构. 埋置式基板的应用解决了BGA与引线键合芯片同面组装情况下芯片封装面高出焊球高度的关键问题. 对封装结构的散热特性进行了数值模拟和测试,结果表明组件具有高的热机械可靠性. 电学测试结果表明组件实现了电功能,从而满足了无线传感网小型化、高可靠性和低成本的设计要求.     

基于光子晶体的太赫兹微带贴片天线的设计

本文设计了一个以二维光子晶体为基底用于太赫兹无线通信的微带贴片天线（0.4-0.6Thz）。太赫兹波介于微 波和光频之间,占有很大的带宽,随着人们对通信质量的要求越来越高,太赫兹通信将成为必然趋势。用二维光子晶 体做基底,有抑制表面波,提高天线的方向性,增益和效率等特性。文章中设计的天线的带宽,增益和方向性分别达 到了31.7%,6.7DB 和8.5DBi,为未来短距离无线通信和太赫兹空间通信提供了参考。本文选用了CST 仿真软件。     

The future of substrate data private line networking

Private line networking for data applications using data rates equal to or less than 64 kb/s, referred to as substrate, is reviewed. Examples of substrate data applications include: automatic teller machine networks, banking teller platforms, and airline flight reservation systems. The fundamental point-to-point and multipoint topologies used in substrate data private line networking are described from both primary data and diagnostic network perspectives. Market and technology trends affecting substrate networking, including analog to digital migration, multichannel-multipoint configurations, tail extensions off DS-1 backbones, hybrid networking, service restoration, disaster recovery, LAN interconnection, and multinational networking, are discussed. Brief remarks concerning future technologies, such as ISDN and wireless applications, are presented     

Design and characterization of single- and multiple-beam mm-wavecircularly polarized substrate lens antennas for wireless communications

Single- and multiple-beam circularly polarized ellipsoidal substrate lenses suitable for millimeter-wave wireless communications have been designed, implemented, and experimentally characterized at 30 GHz. The lenses are made out of low-cost low-permittivity Rexolite material. The single-beam lens achieves a directivity of 25.9 dB, a front-to-back ratio of 30 dB, and an axial ratio of 0.5 dB is maintained within the main lobe. The measured impedance bandwidth is 12.5% within a SWR⩽1.8:1. The single-beam antenna is well suited for broad-band wireless point-to-point links. On the other hand, the multiple-beam lens launches 31 beams with a minimum 3-dB overlapping level among adjacent beams. The coverage of the lens antenna system has been optimized through the utilization of a hexagonal patch arrangement leading to a scan coverage of 45.4° with a maximum loss in directivity of 1.8 dB due to multiple reflections. The multiple-beam lens antenna is suitable for indoor point-to-multipoint wireless communications such as a broad-band local area network or as a switched beam smart antenna. During the proposed design process, some fundamental issues pertaining to substrate lens antennas are discussed and clarified. This includes the depolarization properties of the lenses, the effect of multiple internal reflections on the far-field patterns and the directivity, the nature of the far-field patterns, the estimation of the lens system F/B ratio, and the off-axis characteristics of ellipsoidal lenses     

一种蝶形平面超宽带(UWB)天线的设计

超宽带无线通信技术以其低功耗、高带宽、低复杂度等优点而倍受重视,使用蝶形结构设计了一种新的平面超宽带天线。该天线由同轴馈电,天线的制作是通过在介质基板上下面上分别印刷一个半圆形金属,在上层刻蚀掉2个正方形图案,下层刻蚀掉2个半圆形图案实现。仿真和实物实测结果都可以证实,天线的工作频带为3.1~10.6 GHz,有很好的全向辐射方向图和良好的线性相位响应。因此,该天线的特性能够满足超宽带的要求,可用于无载波超宽带无线数据通信系统。     

Polygonal patch antennas for wireless communications

An effective design of polygonal patch antennas with multifrequency or broad-band operation modes for wireless communications is presented in this paper. It is shown how polygonal patches with suitable features may be obtained after a proper perturbation of conventional rectangular geometries, which inherently present poor bandwidth performances. These perturbed irregular geometries may support multiple resonances and, thus, may present a broad-band or multifrequency operation mode, even employing conventional patch antennas with a single dielectric substrate. These polygonal patches are efficiently analyzed through a numerical code based on the method of moments, with entire domain basis functions that accurately describe the radiation mechanism. After the presentation of the analysis and design techniques, some antenna layouts for modern wireless communication systems will be proposed. Such antennas are designed for both universal mobile telecommunication system and wireless local area network portable equipment with real-life finite ground planes.     

A 5.2-GHz LNA in 0.35-/spl mu/m CMOS utilizing inter-stage series resonance and optimizing the substrate resistance

A current-reused two-stage low-noise amplifier (LNA) topology is proposed, which adopts a series inter-stage resonance and optimized substrate resistance of individual transistors. The characteristics of the series inter-stage resonance in gain enhancement are analyzed and compared with other alternatives. The contradicting effects of substrate resistance on common-source and common-gate amplifiers are analyzed and proposed guidelines for high-gain operation. The LNA is implemented based on a 0.35-/spl mu/m CMOS technology for 5.2-GHz wireless LAN applications. Measurements show 19.3dB of power gain, 2.45 dB of noise figure, and 13.2 dBm of output IP3, respectively, for the dc power supply of 8 mA and 3.3 V.