共查询到20条相似文献,搜索用时 125 毫秒
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在RF LDMOS功率器件中,击穿电压、截止频率fT和导通电阻Ron是器件的关键参数,为提高这几个器件性能参数可采取的各种措施又往往是相互矛盾和相互制约的。文中研究了几个参数之间的关系和优化方案。现在RF LDMOS功率器件在向高工作电压、高输出功率、高可靠性以及脉冲应用等方向发展。所研制器件采用沟背面源结构,采用场板技术降低栅漏电容,采用多晶硅金属硅化物结构降低栅阻。研制结果表明,在漏源工作电压6V、频率520MHz、连续波的测试条件下,输出功率达到5.6W,增益大于12dB,效率大于55%。 相似文献
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高速BiCMOS外延工艺研究 总被引:1,自引:1,他引:0
外延工艺作为BiCMOS的关键工艺,影响着双极和CMOS器件的多项性能参数。文章对高速BiCMOS器件进行外延工艺研究,设计出了合理的外延层参数,并针对该参数进行了外延工艺的研发。高频器件需要超薄的外延层,控制较窄的过渡区是其关键,文章研究了几个主要外延工艺参数对过渡区的影响,并提出了一种通过减压、低温、本征外延得到窄过渡区的工艺方法。试制结果表明自掺杂效应得到明显抑制,1.5μm外延层下过渡区宽度小于0.25μm,外延层质量良好,测试结果表明该工艺能够满足高速BiCMOS器件的需要。 相似文献
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CMOS流量传感器的传热特性分析 总被引:3,自引:0,他引:3
对CMOS流量传感器的传热特性进行了分析研究,提出在器件前后端之间采用隔热结构是提高器件灵敏度的一种有效方法,隔热槽长度是传感器灵敏度的关键参数。实验表明当隔热槽长度为165μm左右时,器件灵敏度最佳。 相似文献
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本文从改进器件结构、提高器件性能的角度出发,对IGBT自产生以来的各种有代表性的优化设计进行了综述,其中重点介绍了抑制闭锁效应、降低正向压降和开关损耗、提高阻断电压和开关速度的一些技术,对几个关键参数之间的折衷问题也进行了一定程度的讨论。 相似文献
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对双极晶体管结构和关键性能参数进行了研究和设计,并进行了流片测试.介绍了器件工艺步骤及其采用的工艺结构.对器件的特征频率、Gummel曲线、发射极电子和空穴浓度、CE击穿特性模拟、β/Ic曲线等关键参数进行了模拟.模拟器件最高特征频率为10 GHz,流片测试最高特征频率为9.5 GHz. 相似文献
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A numerical procedure based on the spectral-domain techniques is formulated to compute all the frequency-dependent normal-mode parameters of general multiple coupled line structures in an inhomogeneous medium. In addition to the phase and attenuation constants for all the normal modes, these parameters include the line-mode and decoupled line modal impedances and the current and equivalent voltage eigenvector matrices of the coupled system. The multiport admittance (and impedance) matrices and coupled line equivalent-circuit model parameters are evaluated in terms of these normal-mode parameters. Numerical results for these normal-mode parameters for typical asymmetric two-, three-, and four-line microstrip structures are included to demonstrate the procedure and the frequency dependence of these parameters 相似文献
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《Solid-State Circuits, IEEE Journal of》1977,12(5):552-559
For the purpose of statistical modeling it is necessary to choose a few independent device parameters. A number of devices are characterized in terms of their Gummel-Poon model parameters. Correlations between these parameters are studied. The parameters are divided into two groups. The first group consists of parameters depending on collector doping. Collector resistance R/SUB C/ can be chosen as the controlling parameter for this group. The second group comprises the parameters influenced by emitter and base dopings. For this group, using the statistical method of factor analysis to analyze these correlations, it is shown that the variation in the measured data can be effectively expressed in terms of only a few controlling parameters. It is shown that the saturation current I/SUB S/ shows good correlations with most of the model parameters and can be used as an independent parameter from which other parameters can then be computed. 相似文献
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Fuk-Kwok Li Held D.N. Curlander J.C. Chialin Wu 《Geoscience and Remote Sensing, IEEE Transactions on》1985,(1):47-56
Problems in the determination of Doppler parameters for spaceborne synthetic-aperture radar (SAR) data processing are examined. The degradations in image quality due to errors in these parameters are summarized. We show that these parameters can be estimated using accurate spacecraft ancillary data. In cases where such data are not available, we propose two techniques to estimate these parameters using the coherent radar return. These techniques were tested with the Seasat SAR data and the test results demonstrate that the accuracies achieved exceed the system performance requirements. Possible applications of these techniques in other areas of SAR data utilization are briefly discussed. 相似文献
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利用Rene95合金在DD3单晶基材的 (0 0 1)面、(10 0 )面和与 (0 0 1)面夹角分别为 4 5°和 2 2 .5°的晶面上进行激光多层涂覆 ,研究了基材晶体取向对单晶显微组织的影响规律。研究表明 ,当实验在基材的择优晶面 { 0 0 1}上进行 ,涂层的组织为定向凝固柱状晶 ,晶体取向与基材的晶体取向相一致 ,一次间距约为 10 μm ,二次臂退化。当实验在基材的非择优晶面 (与(0 0 1)面的夹角θ分别为 4 5°和 2 2 .5°的晶面 )上进行 ,涂层的晶体取向仍然与基材的晶体取向一致 ,但枝晶二次臂出现 ,θ为4 5°角的晶面与 2 2 .5°角的晶面相比 ,枝晶二次臂的发展不平衡性加大。 相似文献
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进一步提高光纤质量的几个技术问题 总被引:1,自引:0,他引:1
王德荣 《光纤与电缆及其应用技术》2005,(4):23-27
对光纤的几个重要质量参数,如动态疲劳参数nd、偏振模色散(PMD)、翘曲度,进行了较深入的探讨,研究了影响这些参数的诸多因素和改善这些参数的途径。 相似文献
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The statistical macroscopic characterization of composite materials in simple and complex electromagnetic environments is addressed. Based on the central limit theorem applied to the random parameters that characterize the microscopic constituents, the probability density function, mean, uncertainty and confidence intervals of various macroscopic effective constitutive material and wave parameters are derived. The implications ofthe randomness of the external field on these parameters are also investigated. 相似文献
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由于正方形二维光子晶体具有光子禁带,所以在光子晶体缺陷处可形成对光子束缚的缺陷本征模.本征模的频率应在光子禁带频率范围内,而光子禁带频率又取决于光子晶体的结构参数.通过有限元法数值计算得到并图示了正方形具有缺陷结构二维光子晶体本征频率和介质柱半径、晶格常数以及介质柱介电常数之间的关系.利用这些关系当增大介质柱半径而相应减小介质柱介电常数时,本征频率将会保持不变.此外由于光子晶体结构参数的不同,本征模对应的电磁场在晶体中的分布也不同,文中图示了电场强度的大小在一些结构中的分布. 相似文献
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Waveguide and resonator perturbation techniques are considered for determining electromagnetic parameters of general biisotropic, or nonreciprocal chiral, materials. The bisotropic materials are the most general linear isotropic media, whose constitutive relations are governed by four complex material parameters. The material parameters of bisotropic media can be obtained through measuring the change in the propagation constant of waveguide modes or measuring the shift in the resonant frequency for resonators with perturbation techniques. To measure these parameters a method utilizing waveguides or cavity resonators with two degenerate modes is proposed 相似文献