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四硼酸锂晶体的声表面波应用 总被引:1,自引:1,他引:1
介绍了新型压电晶体四硼酸锂的压电和声表面波特性,讨论了四硼酸锂晶体基片声表面波器件的制作工艺,总结了近年来四硼酸锂晶体压电器件的研究成果。 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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双火 《激光与光电子学进展》1997,34(3):25-26
三菱材料公司、理化学研究所光动力学中心、东北大学金属材料研究所福田研究室以及该大学电气通信研究所的山之内研究室声称,经共同研究发现四硼酸锂(Li2B4O7)晶体有望作为实用非线性光学元件。该晶体具有如下特性:从Nd:YAG激光产生它的4倍频(波长266nm)和5倍频(213nm)。现在,固体激光正打入使用气体激光的各种领域。在紫外区域,准分子激光正付诸实用,将来这种四硼酸锂晶体作为波长变换元件组合而成的全固体红外激光器有可能取代准分子激光器。迄今,四硼酸锂一直作为弹性表面波用的晶体进行研究。众所周知,用作弹性表面波… 相似文献
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四硼酸锂晶体圆片的加工与表征 总被引:1,自引:2,他引:1
介绍了坩埚下降法生长的优质四硼酸锂晶体(LBO)76mm(3英寸)标准圆片的加工工艺,讨论了LBO圆片的质量。研究表明,所得LBO圆片能够满足目前SAW器件制作的要求 相似文献
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四硼酸锂单晶的弹性,压电及介电性能 总被引:5,自引:0,他引:5
由描述各向异性固体中弹性波的耦合波方程,推导出确定四硼酸锂(Li_2B_4O_7)弹性常数所必须的完整关系式。使用几种不同取向的晶体样品,用传输线路法和脉冲回波重合法测量了六种不同振动模式的谐振频率和声速,由这组数据计算出它的弹性、压电及介电常数。 相似文献
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应用在移动通信中的声表面波滤波器庄直铭声表面波器件(SAWD)是一种在信号处理、频率控制、频率选择、信息捕获诸方面性能十分优良的器件。70年代末,电视机中由十几个元件组成的LC滤波器,逐渐被声表面波滤波器(SAWF)所取代,从而使电路简化,调整方便,... 相似文献
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本文研究了一种直接利用晶体管或场效应管来模拟高Q值电感,并利用此电感来制作L波段和S波段窄带有源滤波器的方法。利用此方法制作了两个高性能的窄带有源带通滤波器:一个中心频率为2.3GHz,其带宽为90MHz左右,带内插入损耗为0dB;一个中心频率在1.5GHz左右,并且中心频率可调,其带宽为80MHz左右,带内有10dB的增益 相似文献
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《Microwave Theory and Techniques》1963,11(3):162-178
Direct-coupled resonator filters in transmission line are discussed. The resonators consist of sections of transmission line coupled either by series capacitances or shunt inductances. Over narrow frequency bands, such filters show characteristics similar to those of lumped-constant filters and their design is straightforward. The design of direct-coupled resonator filters over wide (as well as narrow) frequency bands is presented here using the quarter-wave transformer as a prototype circuit. Several numerical examples (with fractional bandwidths between 10 per cent and 85 per cent) are worked out to illustrate the method. It is shown that the response can be improved by optimizing the line impedances. 相似文献
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《Microwave Theory and Techniques》1968,16(3):147-157
Design techniques and interconnection equivalent circuits are presented for constricting low-cost printed-circuit narrowband complementary filters. The techniques and circuits described allow the achievement of contiguous band multiplexers using a single printed circuit board with no series or shorted stubs. Equivalent circuit transformations useful in obtaining practical designs and experimental results for a two-section stripline complementary filter pair are also given. While emphasis is placed on printed-circuit filters, the interconnection circuits and design techniques presented can be applied in the design of narrowband multiplexers using many other filter types. 相似文献
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Dani M. Lyons Ardalan ArminMartin Stolterfoht Ravi C.R. NagiriRoss D. Jansen-van Vuuren Bhola N. PalPaul L. Burn Shih-Chun Lo Paul Meredith 《Organic Electronics》2014,15(11):2903-2911
Accurate color reproduction using image sensors requires four narrow-band absorbing photodetectors (blue, green, yellow and red). Current photodetectors use a broadband photodetector in combination with color filters, which generally do not have sufficient wavelength discrimination for illuminant independent color recognition. We have developed a green-sensitive organic photodetector, in which color selection is achieved using a narrow-absorbing ketocyanine chromophore, coupled with a low finesse electro-optical cavity inducing further spectral narrowing. The optimized device contained a bulk heterojunction light-absorbing layer comprised of a ketocyanine dye blended with [6,6]-phenyl-C61-butyric acid methyl ester. The photodetector had a response full width at half maximum of 80 nm centered around 525 nm, and an external quantum efficiency of 15% at −1.0 V, which is the highest so far reported for a narrow band green-absorbing organic photodetector. The performance of this detector is sufficient to meet the specifications required by machine vision systems. 相似文献
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窄孔径声表面波滤波器的衍射计算和校正 总被引:2,自引:2,他引:0
本文利用了Fresnel积分的快速算法,对具有抛物线近似的各向异性基片材料计算了叉指换能的衍射频率响应。计算中考虑了收、发叉指换能器之间的距离,声也径比值和抽样频率改变对衍射的影响。由此,可以决定滤波器的最佳设计参数。同时提出了采用校正函数补偿衍射影响的方法。 相似文献