薄膜体声波谐振器技术

以微加工技术制作的薄膜体声波谐振器以及由它连接组成的滤波器为重点,介绍了其工作原理、结构模型以及相关参数,提出了一种薄膜体声波谐振器设计,并模拟了其构成射频带通滤波器的频率特性。     

RF MEMS器件的研究及其应用前景

本文对微机械电容、微机械电感、微机械谐振器/滤波器、微机械传输线、微机械天线阵列和微机械开关等RF MEMS器件的特点、研究现状及其在射频收发模块中的应用进行了综述,并展望了它们未来的发展趋势。     

RF-MEMS的系统级封装

射频(RF)技术在现代通信领域正得到越来越广泛的应用,用MEMS方法制备的射频元件不仅尺寸小、成本低、功能强大,而且更利于系统集成.系统级封装(SIP)寄生效应小、集成度高的优点特别适合用来封装RF-MEMS系统.本文介绍了系统级封装的发展现状特别是在射频领域的应用,同时重点分析了在RF-MEMS系统级封装中封装结构、元件集成、互连及封装材料等几个关键问题.     

新型波浪加权式高性能声表面波滤波器设计

射频滤波器是移动通信中信号传输频率选择、噪声滤除干扰的不可或缺的关键器件。压电薄膜多层衬底结构的声表面波滤波器因具有高矩形度、低损耗等优点在近年来被广泛应用,但其谐振器固有的横向模式会极大影响滤波器性能。为此提出了一种新型的波浪加权式叉指设计的声表面波谐振器,该谐振器通过使用正弦函数作为交叠长度加权包络曲线,能够在不恶化谐振器性能的前提下有效抑制谐振器中的横向模式。将波浪加权式叉指设计的谐振器按照梯形拓扑结构级联,设计并制备了一款尺寸为1.1 mm×0.9 mm×0.55 mm的高性能滤波器。该滤波器中心频率为2.593 GHz,相对带宽为8.8%,插入损耗为0.52 dB。实物测试结果与仿真基本一致。     

基于四模谐振器的新型双通带滤波器设计

提出了一种新型的四模谐振器,并在此基础上设计了一款双通带滤波器。利用奇偶模分析法进行理论分析,采用共面波导异面馈电方式,使四模谐振器中的每两个谐振频率耦合,分别形成滤波器的低通带与高通带。通过射频仿真软件HFSS 研究滤波器主要结构参数对性能的影响并进行优化,对滤波器进行加工制作及测试。测试结果表明双通带滤波器的中心频率分别为2 GHz 和5.4 GHz, 3 dB 相对带宽分别为11.9%和17%,电路尺寸为0.11λg ×0.1λg。所设计的双通带滤波器具有结构新颖、通带宽、尺寸小的特点。     

基于RF MEMS开关的交指型可切换带通滤波器设计

为了有效解决信号/频谱分析仪等微波测试仪器尺寸较大、信号损耗高、选通切换效率差等问题,将射频MEMS开关引入交指型可切换滤波器结构中。通过MEMS四掷开关选择具有不同中心频率的交指型谐振器,实现在6~14 GHz内四个频率的射频信号切换过滤。利用HFSS电磁波仿真软件对滤波结构的几何参数进行优化计算,得到四个可切换频率的插入损耗,分别为1.26 dB@6.86 GHz、1.03 dB@9.16 GHz、1.23dB@11.78 GHz、1.07 dB@12.26 GHz,整体面积约为7.95 mm³。与其他可切换滤波器相比,该可切换滤波器将MEMS四掷开关与交指型谐振器集成到一起,具有低插损、小尺寸、高集成度等优点。     

氧化锌薄膜体声波谐振器的研制

介绍了一种薄膜体声波谐振器和它的制备流程.该谐振器采用氧化锌压电薄膜作为压电材料,通过从硅片背部体刻蚀硅衬底的方法得到谐振器的支持层.为了避免残余应力引起的支持层起皱现象,采用氮化硅/二氧化硅/氮化硅复合膜作为支持层.采用直流磁控溅射的方法制备氧化锌压电薄膜,X射线衍射结果显示,氧化锌压电薄膜C轴择优取向明显,衍射峰半高宽为0.227 3°,显示出较好的结晶质量;扫描电镜观察到氧化锌垂直于薄膜表面的柱形晶粒结构,薄膜表面平整、致密.采用HP8753D射频网络分析仪对该薄膜体声波谐振器样品进行了测试,结果表明,谐振器具有明显的厚度伸缩振动模式,其基频在750 MHz左右,二次谐频在1.5 GHz左右.进一步提高氧化锌压电薄膜的性能,该谐振器可用于射频振荡源和射频前端滤波器中.     

一种体声波滤波器仿真设计分析

文中着重阐述了基于微机电系统（Micro-Electro-Mechanical Systems，MEMS）技术制造的薄膜体声波谐振器／滤波器，简述了它的结构及原理，分析了其主要特征参数和设计方法，并设计了中心频率为2．4GHz，带宽为100MHz的带通滤波器，展示了薄膜体声波谐振器／滤波器的突出性能，为通信MEMS技术的微型化发展提供了更广阔的道路。     

SMD封装声表面波谐振器滤波器

南京电子器件研究所已研制成 SMD封装声表面波谐振器与声表面波滤波器 ,其中心频率为 30 0～1 0 0 0 MHz,外型封装为 QCC8C,SM- 2。这种谐振器与滤波器在低功率 UHF发射机的频率控制、超外差接收机本振、各种无线音频视频传输及通信设备的中频和射频滤波等领域有广泛应用SMD封装声表面波谐振器滤波器     

C波段横向激励薄膜体声波谐振器设计与制备

针对未来移动通信对射频前端器件提出的多频率、高集成新要求,开展了兼具声表面波(SAW)谐振器和薄膜体声波谐振器(FBAR)技术特点的新型横向激励兰姆波谐振器研究。该文介绍了基于c 轴择优取向氮化铝(AlN)压电薄膜的C波段横向激励薄膜体声波谐振器(XBAR)的结构设计、参数优化和制备方法,并进行了工艺验证。通过剥离和刻蚀等步骤制备了谐振频率4.464 GHz、品质因数3 039、品质因数与频率之积(f ×Q )达到1.56×1013 GHz、面积小于0.12 mm2 的低杂波XBAR谐振器,并仿真分析了其用于射频滤波器的可行性。该研究为进一步研制多频率、高集成的小型化XBAR滤波器组件提供了有效的设计技术和工艺技术支撑。     

Substrate Integrated Waveguide Loaded by Complementary Split-Ring Resonators and Its Applications to Miniaturized Waveguide Filters

A substrate integrated waveguide with square complementary split-ring resonators (CSRRs) etched on the waveguide surface is investigated in this paper. The proposed structures allow the implementation of a forward-wave passband propagating below the characteristic cutoff frequency of the waveguide. By changing the orientations of the CSRRs, which are incorporated in the waveguide surface and can be interpreted in terms of electric dipoles, varied passband characteristics are observed. A detailed explanation for the generation and variations of the passbands has been illuminated. The application of this waveguide and CSRR combination technique to the design of miniaturized waveguide bandpass filters characterized by transmission zeros is then illustrated. Filter design methodology is examined. These proposed filters exhibit high selectivity and compact size due to the employment of the subwavelength resonators and an evanescent-wave transmission. By slightly altering the configuration of the CSRRs, we find that the propagation of the TE₁₀ mode can be suppressed and filters with improved selectivity and stopband rejection can be obtained. To verify the presented concept, three different types of filters are fabricated based on the standard printed circuit board process. The measured results are in good agreement with the simulation.     

微尺度下新型MEMS滤波器的研究

分析了MEMS共面波导结构,在MEMS共面波导的基础上设计了一种MEMS滤波器,研究了它的电磁学、热应力等微尺度效应.在这些微尺度条件下分析了器件的相关性能,这些参数为获取实际的MEMS滤波器提供了一些有意义的数据.若改变设计参数,可获取其它同类型的带阻、带通滤波器件,为无线通信中的MEMS器件研究在材料选择、器件设计等方面提供了一些理论依据及其实际经验.     

微带发夹型谐振器滤波器的实验研究

微带发夹型谐振器滤波器具有尺寸小、成本低、易于集成等优点,在微波平面电路的设计中有着良好的应用前景.此前已有一些文献对这类滤波器进行过研究,但一般都是只针对某一种特定的发夹型谐振器进行滤波器的分析设计,而没有对各种不同谐振器的性能指标与滤波器设计要求进行比较研究.本文使用几种不同的发夹型谐振器和不同耦合方式分别设计了三阶和四阶带通滤波器,通过实验对这几种谐振器滤波器进行了分析研究,得到了一些具有实际应用价值的结论.     

基于频率变换的双通带腔体滤波器的研究

该文基于频率变换的方法设计了两种结构的双通带的腔体滤波器,一种是通过谐振器之间直接耦合实现的;另一种是在谐振器之间引入交叉耦合实现的,从而达到产生传输零点的目的。首先根据设计指标,采用频率变换的方法,计算得到谐振器间的耦合系数和外部Q值,然后利用Ansoft HFSS建立同轴腔体滤波器的模型并进行仿真,仿真结果与ADS中等效电路得到的理论结果基本吻合,从而验证了这种方法的正确性。最后通过对级联型结构与交叉耦合型结构双通带腔体滤波器的比较,得出后者比前者具有更好的带外抑制特性。     

Miniaturized hairpin resonator filters and their application toreceiver front-end MICs

The authors describe the fundamental characteristics of miniaturized hairpin resonators having parallel coupled lines and show their applications to bandpass filters and receiver front-end microwave integrated circuits (MICs). A method for calculating filter coupling parameters using a general-purpose microwave circuit simulator is presented. The bandpass filters have a suitable structure for MICs, and their size is one-half that of conventional hairpin resonators without increasing insertion losses. Trial receiver front-end MICs using these filters have been developed and have shown good characteristics such as low noise and a high image suppression ratio. They are applicable to a frequency range above the L-band     

A joint field/circuit model of line-to-ring coupling structures andits application to the design of microstrip dual-mode filters and ringresonator circuits

A joint field/circuit model is proposed in this paper to characterize a class of line-to-ring coupling structures for design and optimization of microstrip dual-mode filters and ring resonator circuits. The generic model is derived from field theory and presented in terms of circuit elements by applying a newly developed numerical deembedding technique called “short-open calibration” in a deterministic method-of-moments scheme. It provides a new design strategy for characterizing and optimizing electrical performance of the line-to-ring coupling structures. Such three-port topologies are explicitly formulated by using an equivalent network having circuit elements calculated by the proposed joint field/circuit model. Three microstrip tightly coupling geometries and their related ring resonators are studied with the extracted J-inverter susceptance parameters. Experiments are performed to validate the joint model and also show coupling characteristics of the three types of line-to-ring circuit for the design of ring resonators and dual-mode filters. With this new technique, an optimized microstrip dual-mode filter is successfully designed and the prediction agrees well with our measurements     

一种微带交指型滤波器的改良型设计

论述了用Ansoft公司的Designer微波设计软件设计一种改良型的微带交指型带通滤波器。描述了微带交指型滤波器的设计方法,通过实例对这种改良型的微带交指带通滤波器进行了计算机最优化仿真设计,并给出了优化结果。微带交指型滤波器结构紧凑、指标优良,是微波混合集成电路中常见的形式,原理上是由1/4波长平行耦合线滤波器的谐振器折叠而成。     

Miniaturized Hexagonal Stepped-Impedance Resonators and Their Applications to Filters

Miniaturized hexagonal stepped-impedance resonators and their applications to bandpass filters are presented. Based on the odd- and even-mode equivalent circuits, the resonance characteristics of these resonators are investigated. A series of circuit configurations, including the third-order Chebyshev, trisection, and fifth-order cascaded trisection filters, are constructed by the proposed resonators. These filters are very compact and have good stopband responses. Measured results validate the analysis and theoretical prediction with good agreement.     

Tunable stop-band filter at Q-band based on RF-MEMS metamaterials

Presented for the first time is a metamaterial transmission line that combines complementary split ring resonators (CSRRs) and RF microelectromechanical systems (RF-MEMS). The device consists of a coplanar waveguide structure loaded in its central strip with CSRRs embedding RF-MEMS variable capacitors. Owing to the presence of the CSRRs, the structure behaves as a stop-band filter. Through the actuation of the electrostatic RF-MEMS devices, the electrical characteristics of the CSRRs are modified so that their resonance frequency, and as a result the central frequency of the stop-band filter, can be tuned. This is the first time that an RF-MEMS tunable metamaterial-based filter has been designed for operation at Q-band.