首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 217 毫秒
1.
提供了一种考虑到微制造工艺实际的对微胶体推进器的起始电压进行估计的方法.本方法的关键在于把基于深度干法腐蚀的微推进器的两极简化成一组双曲等势面中的两个,利用拉麦方程得到微推进器两极间静电场分布的近似解.进而分析微胶体推进器源极顶端工质液滴的静电力和表面张力的平衡,得到微胶体推进器的起始工作电压.按照工作电压的估计方程,基于ICP腐蚀,设计了4种微胶体推进器.利用悬臂梁和电涡流微位移传感器对微推进器的测试结果表明,利用该方法对微胶体推进器起始电压进行的估计和实际测试结果有很好的一致性.  相似文献   

2.
提供了一种考虑到微制造工艺实际的对微胶体推进器的起始电压进行估计的方法。本方法的关键在于把基于深度干法腐蚀的微推进器的两极简化成一组双曲等势面中的两个,利用拉麦方程得到微推进器两极间静电场分布的近似解。进而分析微胶体推进器源极顶端工质液滴的静电力和表面张力的平衡,得到微胶体推进器的起始工作电压。按照工作电压的估计方程,基于ICP腐蚀,设计了4种微胶体推进器。利用悬臂梁和电涡流微位移传感器对微推进器的测试结果表明,利用该方法对微胶体推进器起始电压进行的估计和实际测试结果有很好的一致性。  相似文献   

3.
郭文彬  李航 《信号处理》2012,28(6):799-805
针对稀疏流信号,提出了一种自适应卡尔曼滤波恢复方法,该算法基于压缩感知AIC结构,用有限长的窗口对信号进行观测,利用前后窗内信号之间的相关性,建立信号的状态转移方程,并与压缩感知获得的观测方程共同构成信号的状态空间模型,进而利用降阶的卡尔曼滤波算法近似得到信号的最小均方误差估计。信号重构阶段通过卡尔曼滤波迭代逐渐得到精确的支撑集,与以往仅用起始阶段的恢复结果获得支撑集的方法相比,本算法对起始阶段恢复支撑集的算法的精确程度要求不高,从而降低了整个算法的复杂度和要求的观测维度。仿真结果显示,这种自适应的卡尔曼滤波算法在宽带流信号的恢复中可以有效地降低所需观测维度,且最终结果可近似地收敛到信号的最小均方误差估计。  相似文献   

4.
设计了一种基于亚阈值区MOS管的低功耗基准电压源。利用MOS管差分对的栅源电压差对MOS管的栅源电压进行温度补偿,从而得到基准输出电压。采用0.18 μm 混合信号CMOS工艺进行设计与仿真。结果表明,该基准电压源的最小工作电压为1.25 V,在0 ℃~80 ℃温度范围内的温度系数为6.096×10-5/℃。  相似文献   

5.
顾晓丽  刘一清  李中楠 《半导体技术》2012,37(8):590-593,611
介绍了一种基于0.18μm CMOS工艺,具有开关功能的低压集成温度传感器。该温度传感器利用半导体pn结的电流电压与温度有关的特性,获取双极晶体管基极-发射极电压差值ΔVBE,采用仪表放大器进行后级放大。仪表放大器由两个采用折叠式共源共栅结构,带有PD开关信号的运算放大器作为反馈系统,放大倍数为7。用ADE工具,对整个电路在工作电压1.8 V、偏置电流20μA下进行仿真,得到其精度为1.58 mV/℃,再在不同工艺角下进行仿真验证。版图总面积为320μm×280μm。该设计已经在一款数字视频芯片中得到实现,用于实时检测芯片温度。实际测试结果与模拟仿真结果基本相同。  相似文献   

6.
基于介电润湿效应的微液滴操控   总被引:1,自引:0,他引:1       下载免费PDF全文
基于介电润湿的微液滴操控已被众多学者实现,但微液滴接触角在饱和阶段随电压变化的数学关系仍未得到较好解决,为此,基于能量最小化原理对Young-Lippmann方程进行了补充和改进.结合理论计算和数值仿真设计了一种叉齿状驱动电极单元数字微流控芯片,并加工出介电层分别为SiO2及SiO2-Si3N4-SiO2两种结构的芯片.实验结果表明,在接触角饱和阶段,所改进的Young-Lippmann方程能在一定程度上反映微液滴接触角的变化趋势.此外,SiO2-Si3N4-SiO2复合介电层结构中的微液滴操控电压低于SiO2单一介电层中微液滴操控电压.  相似文献   

7.
一种利用发光光谱估计LED正向电压的方法   总被引:2,自引:2,他引:0  
提出了一种通过发光光谱估计发光二极管(LED)正向电压的方法。推导了LED正向电压与结温的关系,探讨了利用发光光谱估计结温的方法,从而建立了发光光谱和正向电压的联系。本文方法不需要直接测量结温和理想因子等参数,只由发光光谱就可得到较为准确的LED正向电压值。实验结果表明,正向电压的光谱估计值和实际测量值能够较好的吻合。  相似文献   

8.
为了减小电磁干扰(Electromagnetic Interference,EMI)引起的DC/DC转换器输出电压噪声,消除负载变化引起的稳态误差,提出了一种基于改进的扩展卡尔曼滤波器(Extended Kalman filter,EKF)的电感电流观测器.首先,介绍了Boost型转换器的状态空间方程和扩展卡尔曼滤波器;之后提出负载估算算法,对EKF进行改进.利用改进EKF的输出电压、电感电流和占空比即可估算出实际负载值,从而实时更新改进EKF的参数,使电流观测器可以准确估计电感电流;最后对提出的电流观测器进行了仿真验证.仿真结果表明,在负载突变时,改进EKF可以对EMI引起的输出电压噪声进行有效滤波,同时准确估计电感电流,保证了DC/DC转换器输出电压的准确性.  相似文献   

9.
针对获取船舶状态信息的需求,研究了AIS信号码元序列估计技术,提出了一种新的AIS信号码元序列估计算法。利用AIS信号的先验信息构造了AIS样本信号,采用雷达信号处理中模糊函数的思想,获得AIS信号的起始时刻、频偏、幅度等参数进行有效估计,进而估计出AIS信号的码元序列。该方法不需要对AIS信号进行解调。算法的有效性通过对实际接收到的AIS信号数据进行处理得到了验证。  相似文献   

10.
为了正确反映基于光电位置敏感器(PSD)的微位移传感器的特性,首先介绍了一维光电位置敏感器的工作原理并分析了利用PSD结合光学三角测量法将位移信号转换成电压信号的工作原理,得出基于PSD的微位移传感器被测试件位移量与相关测量电路输出电压(S,V)关系特征,然后基于最小二乘估计算法基本原理,提出了运用MAT-LAB语言建立PSD的微位移传感器(S,V)关系特征的数学模型的方法,给出了建模的程序流程图以及仿真结果。  相似文献   

11.
Onset voltage plays a crucial role in the design of a microcolloid thruster. This paper presents a methodology to estimate the onset voltage for the design of a new microfabricated colloid thruster. The basic idea of this method is to simplify the source emitter and the extractor of the microthruster as two hyperboloids of two sheets of a set of equal potential surfaces. The maximum electric field between electrodes is modeled using the Lame/spl acute/ method, on which a method to estimate the onset voltage is developed. To avoid the aberration of electric field caused by protuberances on the surface of the source emitter, the height of the source emitter must be much greater than that of protuberance. Experiments conducted on the homemade microcolloid thrusters, designed based on the proposed onset voltage estimation, verify the correctness of the approach.  相似文献   

12.
化学能推进系统功耗低、结构简单紧凑 ,适于微小型化。本文介绍了两种微小型化学能推进器的结构设计、制造工艺、仿真和实验结果。 (1)微小型固体推进器阵列 ,由点火电路、工质贮腔和喷口阵列等部件构成 ,根据理论分析 ,对结构尺寸进行了优化 ,改变单元尺寸 ,可以得到 0 .5~30mN不同推力级别 ,比冲 (Isp)大于 30 0s ;(2 )同相催化的单组元液体推进器 ,其关键部件是微小型推力室 ,包括催化反应腔和喷管等结构 ,试验样机的冲量输出分辨率优于 80 μNs。  相似文献   

13.
聚光系统构形对激光推力器推进性能的影响   总被引:8,自引:0,他引:8  
在喷管与聚光系统一体化设计时,聚光系统因其同时承担聚光和喷管两项功能而成为激光推力器的重要组成部分。通过改变聚光系统内表面的母线方程,可以改变点火区的大小、形状、点火区与聚光系统内表面的距离及喷管长度等参数,而这些参数都会对激光推力器的推进性能产生影响。针对不同的聚光系统构形建立了相应的点火模型,数值计算与实验结果一致,即当注入能量不超过60 J时,在喷管出口直径相同的条件下,抛物形喷管点聚焦方式比环聚焦方式所获得的冲量耦合系数大,可达38.84×10-5N.s/J;而冲量耦合系数对点火区与聚光系统内表面的距离及喷管长度等参数并不十分敏感。研究结果对于吸气式激光推力器的喷管构形设计具有指导意义。  相似文献   

14.
掺杂聚合物的激光微烧蚀推进性能研究现状   总被引:1,自引:0,他引:1  
基于激光微烧蚀聚合物产生微冲量这一原理,研究10^-5 N·s至10^-7N.s量级冲量的激光微推力器是当前一个研究热点。聚合物对入射激光的吸收率往往很低,掺杂是提高聚合物的激光微烧蚀性能的一个重要途径。回顾了掺杂聚合物的推进性能实验,分析了不同掺杂下推进性能的实验结果,认为以碳、红外染料或者含能材料作为掺杂剂可以获得较好的推进性能参数,含能聚合物是较好的备选靶材。为国内掺杂聚合物激光微推进性能的研究提供了有益参考。  相似文献   

15.
In this paper, an energy estimation methodology based on performance monitor counters (PMC) is proposed to estimate the energy consumption of RVC-CAL video codec specifications. The proposed PMC-driven methodology is able to automatically identify the most appropriate events and training data to cover the main application characteristics. In addition, knowledge of the hardware platform employed is not required. Therefore, this methodology can be easily implemented on other PMC-available systems while keeping the estimation accuracy. It is worth noting that this is an attractive asset to analyze the energy consumption of RVC-CAL codec specifications. Besides, the methodology reduces the PMC redundancy and, thus, the overhead introduced when applied to on-line power management. Experimenting on two RVC-CAL decoders, H.264 and MPEG4 Part2 SP, a coarse estimation model based on instructions per cycle (IPC) and the proposed PMC-driven model are compared. The results show that the PMC-driven model can achieve for the H.264 and MPEG4 Part2 SP decoders average estimation errors of 5.95% and 5.01%, respectively, in comparison to the 17.11% and 13.65% average errors obtained with the IPC-based model. As a consequence, this methodology is suggested to be combined into the RVC framework to help the designer to have an overview of the energy consumption of the specification actors at earlier design stages.  相似文献   

16.
基于求不考虑边缘电容的静电微执行器动态Pull-in参数的能量分析法,并结合边缘电容的模型推导出考虑边缘电容情况下静电微执行器的动态Pull-in参数的计算方法。将不考虑边缘电容条件下的静电微执行器的动态Pull-in参数和考虑边缘电容条件下的静电微执行器的动态Pull-in参数进行比较,得到这两种条件下静电微执行器的动态Pull-in参数的不同以及边缘电容对静电微执行器动态Pull-in参数的影响:考虑边缘电容的Pull-in电压小于不考虑边缘电容的Pull-in电压;在边缘电容模型下,平行板长度的变化对Pull-in电压的影响很大,但是对Pull-in位移却没有影响,平行板宽度的变化对Pull-in电压的影响较小,但是对Pull-in位移的影响很大。  相似文献   

17.
《Mechatronics》2006,16(7):379-387
In this article, a novel piezoelectric cantilever bimorph micro transducer electro-mechanical energy conversion model is proposed. Based on the curvature basis approach, the relationship between the deduced voltage and the mechanical strain induced piezoelectric polarization is formulated. In addition to the working equation for piezoelectric sensors, the damping effect is included to enable the resonance frequency, the maximum induced voltage at the resonance, the conversion energy density and the dimensions of the piezoelectric micro power generator to be analytically estimated. The analytical model shows that the vibration-induced voltage is proportional to the excitation frequency and the width of the device but is inversely proportional to the length of the cantilever beam and the damping factor. To verify the theoretical analysis, two micro transducer clusters are fabricated. The experimental results demonstrate that the maximum output voltage coincides with the energy conversion analytical model.  相似文献   

18.
Parametric yield loss has become a serious concern in nanometer technologies. In this paper, we propose a methodology to estimate and optimize the parametric yield of a design in the presence of process variations. We discuss the impact of leakage on parametric yield given that leakage causes the parametric yield window to shrink by imposing a two-sided constraint in conjunction with performance targets on the yield window. We present a mathematical framework for yield estimation under process variation for a given power and frequency constraints. The model is validated against Monte Carlo SPICE simulations in a 90-nm CMOS process and is shown to have a typical error of less than 5%. We then demonstrate the importance of optimal supply and threshold voltage selection for yield maximization. Our results show that parametric yield is highly sensitive to supply voltage with only a 5% change in the supply voltage potentially leading to nearly 15% yield degradation. We also investigate the sensitivity of parametric yield to required frequency and power constraints. Finally, we apply the proposed framework to the problem of maximizing the shipping frequency in the presence of given yield and power constraints.  相似文献   

19.
This paper presents a methodology to estimate the dissipation of energy in hardware, at any level of abstraction, with Powersim. Powersim is a C++ class library aimed to the calculation of energy dissipation of hardware described in SystemC. To this end C++ operators are monitored and a different energy model is used for each data type. Energy models are functions of operator inputs, constant parameters and variables, like supply voltage. The main advantage of this approach is that energy estimation does not require any change in the source code describing the hardware. As application examples, the computational complexity of a JPEG encoder, implemented in a FPGA, and a FIR filter, implemented in a microcontroller, are presented.  相似文献   

20.
In seismic reflection prospecting for oil and gas a key step is the ability to estimate the seismic wavelet (impulse response) traveling through the Earth. Such estimation enables filters to be designed to deblur the recorded seismic time series and allows the integration of “downhole” and surface seismic data for seismic interpretation purposes. An appropriate model for the seismic time series is a noisy-input/noisy-output linear model. The authors tackle the estimation of the impulse response in the frequency domain by estimating its frequency response function. They use a novel approach where multiple coherence analysis is applied to the replicated observed output series to estimate the output signal-to-noise ratio (SNR) at each frequency. This, combined with an estimate of the ordinary coherence between observed input and observed output, and with the spectrum of the observed input and cross-spectrum of the observed input and output, enables estimation of the frequency response function. The methodology is seen to work well on real and synthetic data  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号