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报道在Y旋127.86°X传LiNbO_3基片上采用1/8λ_0,5/8λ_0结构的切指加权换能器的声表面波滤波器,成功地研制了中心频率为40MHz,3dB带宽为20MHz,矩形系数(Δf_40dB/Δf_3dB)为1.48,带内波动<1.2dB,带外抑制>40dB.插入损耗<38dB,相对带宽(Δf_-3dB/f_0)大于50%的滤波器。 相似文献
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回顾了低损耗声表面波滤波器的主要设计方法,介绍了镜像阻抗连接换能器结构中调整滤波器带宽的设计技术,给出了在960MHz高频下的两种试验结果,相对带宽分别为1%和2%,插入损耗小于5dB,阻带抑制优于50dB。 相似文献
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单相单向换能器的低损耗SAW滤波器 总被引:4,自引:3,他引:1
概述了采用分布式反射的单相单向换能器及其设计,特别推荐了电极宽度控制的单相单向换能器,并报道了我们制作的几种低损耗滤波器结果。单级低损耗滤波器插入损耗为4.7~6.5dB,带外抑制达50dB。两级低损耗滤波器获得带外抑制近90dB,而插损仅为10dB。 相似文献
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本文给出了一种新颖的微波有源滤波器的拓扑结构及综合方法,并对有源滤波电路进行了计算机模拟,结果表明本文给出的微波有源滤波器电路具有优良的的窄带滤波特性,通带内正向增益大于10dB,带外抑制大于30dB。 相似文献
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本文讨论了研制的两种无绳电话机用声表面波滤波器,中心频率为46.57MHz和49.9MHz;△f_(-3dB)=1.7MHZ;插损≤10dB;△f_(-40dB)/△f_(-3dB)≤3.5;阻带抑制≤-40dB。采用了低插损的三换能器结构。输入叉指换能器采用了波阵面均匀的孔径加权和相位加权,减小了变迹损耗。理论计算与实验结果一致。 相似文献
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集成900MHz陶瓷介质滤波器的实现 总被引:5,自引:0,他引:5
本文给出了一种新颖的具有高选择性、低损耗移动通信用的集成一体化陶瓷介质滤波器的结构和设计方法,重点给出了结构参数与电参数之间的关系。实验结果表明本文给出的设计方法是有效的。滤波器带内插损小于1dB,带外抑制大于30dB。整个电路尺寸6mm×18mm×12mm。 相似文献
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为满足温漂要求,同时避免驻波效应,利用剥离工艺在石英基片上制作了中心频率为1128MHz,3dB带宽为2.8MHz,插入损耗>-12dB,带外抑制>40dB的高频窄带声表面波滤波器。 相似文献
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针对LTE MTC蜂窝物联网通信下的应用场景,本文给出了一种基于TSMC 65nm CMOS LP工艺设计的AB类线性功率放大器,为达到一定的功率增益要求,采用两级级联结构,包括驱动级和功率级,两级电路均采用差分结构,可以在不提高电源电压的情况下,达到足够的输出功率和线性度,同时还有利于抑制共模噪声,减小寄生参数及键合线电感对电路性能的影响。为了避免晶体管被击穿,同时提高输入输出端口之间的隔离度,两级电路均采用共源共栅(Cascode)结构,后仿真结果表明,电源 电压3.3V情况下,功率放大器在1180MHz~1920MHz频段工作稳定,输入反射系数S11<-10dB,输入匹配良好,输出1dB压缩点为24.1dBm,饱和输出功率大于26dBm,功率增益大于20dB,输出1dB,压缩点出的功率附加效率25%,峰值效率达到30%。 相似文献
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本文论述的S波段频率综合器,频率范围是2.61 ̄3.96GHz,频率步进为2.5MHz,相位噪声指标〈-(88 ̄93)dBc/Hz,长期频率稳定度为1×10^-9/日,杂散抑制优于55dB,谐波抑制优于50dB,输出功率大于14dBm。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
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The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
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The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
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Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's. 相似文献
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Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it. 相似文献
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A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working. 相似文献
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It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory. 相似文献
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《中国通信》2014,(7)
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks 相似文献