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光纤通信系统中,前置放大器用于检测光电探测器输出的微弱电流,40Gb/s光通信系统对前置放大器的基本指标要求为带宽、跨阻增益和等效输入噪声电流。南京电子器件研究所在国内首次利用0.2μm的GaAs低噪声PHEMT工艺成功地研制了前置放大器芯片,单管栅宽为60μm,放大器的静态工作点为5V/60mA。测试结果显示:前置放大器3dB带宽超过40GHz,跨阻增益为46dBQ, 相似文献
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MEMS加速度计接口电路主要采用传统sigma-delta架构实现,但这种方式中的电路失调电压很容易产生积分饱和现象.为解决这个问题,本文设计了一种可以用于钻井、石油勘探等微弱信号检测的新型数字电容接口电路.该设计在电容式MEMS加速度传感器基础上,采用FPGA实现数字三阶环路滤波器,构成5阶sigma-delta系统.采用数字环路滤波器降低了ASIC模拟电路版图设计与芯片测试难度,利于快速优化环路滤波器设计参数,改善系统稳定性和优化系统噪声性能.前置放大器采用一种相对简单的相关双采样技术,能够有效减小前置放大器的失调电压.根据MEMS加速度计前置放大器输出信号符合正态分布的特点,设计了带有一定预测功能的8-bit瞬时浮点ADC,实现模拟与数字环路滤波器互联.在200Hz带宽内,该接口电路系统噪声基底达到53.09ng/rt(Hz),满足系统噪声设计要求.前置放大器与ADC采用XFAB XH018混合信号CMOS工艺流片,开环测试表明,前置放大器的灵敏度和噪声分别为0.69V/pF和3.20μV/rt(Hz). 相似文献
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潘镜敏 《光纤与电缆及其应用技术》1981,(5)
本文根据网络分析理论,通过光纤模拟通信系统的接收机前置放大器的定性分析,以商榷的方式建议进一步明确,(1)在工程应用中,应根据放大器具体的输入量和输出量分别为电压或电流,选择一定的转移函数,以便有效地表征放大器的增益、带宽和相位特性。(2)带宽是隶属于转移函数的。放大器的带宽应是指上述选定的转移函数的带宽。(3)要改善放大器一定的转移函数的稳定性、带宽和线性度,必须选用一定的负反馈类型。 相似文献
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前一期已就如何设计均衡器以及前置放大器电路的结构、工作原理做了介绍,这一期将讲述制作的要点。通过测试该机在可听频带内RIAA偏差在+0.2dB以内,MC唱头放大器的输入电平和前置放大器的输出电平都在希望的范围内。 相似文献
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《世界专业音响与灯光》2008,(4):53-54
MA-1小型话筒前置放大器
MA-1是一部小型、多用途的话筒前置放大器(图1),内置48V幻象供电,非常适合配置于电脑系统中,作为高质量音频的网络会议系统或音频分析软件的话筒收音放大器使用。它配置一个平衡式卡依话筒输入、带峰值显示的输出增益控制、平衡式线路电平输出及一个3.5mm小型话筒输出.可直接连接到标准电脑声卡的话筒输入端; 相似文献
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从近年Marantz产品的更新、发展情况来看,Hi-Fi音响器材绝对是Marantz新产品路线的重中之重,先是Marantz SA-7S1 SACD/CD播放机、SC-7S2前置放大器及MA-9S2功率放大器组合的旗舰级SACD播放系统大张旗鼓地推出,其后一年,准旗舰级SACD播放系统SA-11S2 SACD/CD播放机、SC-11S1前置放大器及SM-11S1功率放大器亦迅速上市, 相似文献
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Tatsushi Ooba 《Circuits, Systems, and Signal Processing》2000,19(3):187-196
The stability of two-dimensional (2D) dynamics is studied from the viewpoint of quadratic Lyapunov stability. An already-known simple sufficient condition for the stability of 2D dynamics is first reconsidered by introducing a new notion about the stability of a pair of matrices. It is interpreted as a condition for step-by-step contractive stability in a suitably selected state coordinate. In this direction, some necessary and sufficient conditions for the stability of 2D dynamics are shown in detail. The meaning of the original simple sufficient condition is further clarified in this extension. A condition for being free of overflow oscillations in saturation arithmetic is added as a special topic of the Lyapunov stability of 2D dynamics. 相似文献
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主要对工程稳定性的问题展开探讨.首先在总结大科学工程项目的干扰稳定性因素基础上,给出了度量稳定性概念,并且提出一种时空耦合的误差分析方法来表征稳定性控制精度.结合柔度曲线方程,分析稳定性设计关键参数和控制方法.一方面,为进行大科学工程项目的结构设计提供一种稳定性精度预估的方法,考虑到环境干扰因素对大规模、大尺度的科学工程稳定性的影响,并结合稳定性设计的关键参数,在限定条件下实现稳定性的设计要求;另一方面,对现存的_T程结构,可完成相关的验证计算,根据需要可采取相应的减振方法;根据分析计算结果,提出结构优化设计的方法,为其他大科学工程的稳定性设计提供参考. 相似文献
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Tamal Bose M. -Q. Chen David A. Trautman 《Circuits, Systems, and Signal Processing》1994,13(5):601-614
A special class of complex biquad digital filters called orthogonal filters are investigated for stability under two's complement
quantization. A sufficient condition is derived for the asymptotic stability of the nonlinear filter. Bounds on the possible
limit cycles are also obtained. Using these bounds, any given filter can be tested for stability. The stability triangle is
then scanned using a dense grid, and each point on the grid is tested for stability/limit cycles. By this method, the stability
region given by the sufficient condition is extended. Regions within the linear stability triangle where various types of
limit cycles are possible are also identified. 相似文献
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从理论和实验上对利用宽带KrF激光抽运SF6产生的受激布里渊散射(SBS)的脉宽稳定性进行了研究。获得了受激布里渊散射脉宽稳定性随抽运功率密度稳定性、抽运脉宽稳定性及介质气压变化的规律。发现受激布里渊散射脉宽的稳定性与抽运激光的稳定性直接相关,抽运激光的稳定性越好,获得的受激布里渊散射脉宽相对稳定性也越好。抽运光脉宽和能量的不稳定都会造成所产生的受激布里渊散射脉宽不稳定。在较低抽运功率密度情况下抽运光脉宽和能量的波动对受激布里渊散射脉宽稳定性的影响都不可忽略,但在较高抽运功率密度情况下受激布里渊散射脉宽稳定性主要受抽运光脉宽波动的影响。对结果进行了分析和讨论,获得脉宽稳定性较好的受激布里渊散射输出的条件是,使用脉宽稳定性较好的抽运光和在保证没有其他非线性效应产生的情况下,尽可能提高抽运光的功率密度和介质气压。 相似文献
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The thermal and electro stability of multi-finger heterojunction bipolar transistors (HBTs) with different structures were analyzed and discussed simultaneously. The thermal stability of the devices with different layout struc-tures was assessed by the DC-Ⅳ test and thermal resistance calculation. Their electro stability' was assessed by the calculation of the stability factor K based on the S parameter of the HBT. It is found that HBTs with higher thermal stability are prone to lower electro stability. The trade-off relationship between the two types of stability was explained and discussed by using a compact K-factor analytic formula which is derived from the small signal equivalent circuit model of HBT. The electro stability of the device with a thermal ballasting resistor was also discussed, based on the analytic formula. 相似文献
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Intrinsic stability of the heterojunction bipolar transistor(HBT) was analyzed and discussed based on a small signal equivalent circuit model.The stability factor of the HBT device was derived based on a compact T-type small signal equivalent circuit model of the HBT.The effect of the mainly small signal model parameters of the HBT on the stability of the HBT was thoroughly examined.The discipline of parameter optimum to improve the intrinsic stability of the HBT was achieved.The theoretic analysis resul... 相似文献
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A tabular stability test for two-dimensional (2-D) discrete systems that was published in these Transaction is shown to be not correct. It is also shown that the claimed new method that it introduced to extend stability conditions from one-dimensional (1-D) to 2-D systems relies on a mathematically inviable argument. The paper tries to find a similar but correct algorithm and stability conditions. The outcome of the search after a stability test with similar algorithm is a variant of the Maria-Fahmy 2-D stability test for which a more concise set of necessary and sufficient conditions for stability are obtained. The search after stability conditions of similar appearance that can be posed on the correct algorithm, yields new necessary conditions for 2-D stability that resemble stability conditions associated with the "reflection coefficient" parameters in the 1-D Schur test. 相似文献