共查询到20条相似文献,搜索用时 15 毫秒
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《Solid-State Circuits, IEEE Journal of》2009,44(11):3067-3078
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高精度、高速、体积小、低功耗的定时器为激光飞行时间测量应用的关键部件.在单一程式逻辑芯片上成功制作具备上述优点且内含自我校准电路的完整时间数码转换器,使用最近提出的"分支式传递延时(PD)链"作时间内插,对不足计时周期的时段作细分计量.实验证实线性度达0.23%,比传统"单线式"PD链提高10倍,且其线性不受温度与电压影响.单发分辨率为1.459 ns,多发统计分辨率大约0.7 ns.本文也提出了分辨率提高到0.1 ns的方法. 相似文献
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Interpolative digital-to-analog converters generate an output that has only a few analog levels. They provide fine resolution by oscillating rapidly between these levels in such a manner that the average output represents the value of the applied code. Here we describe an improved method of interpolating that results in reduced noise in the signal band. A theory of the interpolation, confirmed by experiments, demonstrates that switching between only two levels at 1.3 mHz could provide 16 bit resolution for telephone signals. 相似文献
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Burkert Peter Fergg F. Fischer H. 《Geoscience and Remote Sensing, IEEE Transactions on》1983,(3):345-349
More precise information on the chemisty, dynamics, and energy budget of the middle atmosphere can be derived from globally and simultaneously measured concentration profiles of a substantial number of atmospheric trace gases. Such a data base can be obtained from infrared limb spectra which are recorded by spaceborne instruments. Fourier transform spectrometers are especially appropriate for such a task. In this paper are discussed characteristic features and performance parameters of a compact high-resolution (0.05 cm-1) rapid-scanning (1 s) interferometer for measurements in the 2 to 15-?m region. Technical data of a cryogenic version as well as of an uncooled satellite instrument are presented. 相似文献
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《Solid-State Circuits, IEEE Journal of》1986,21(3):446-452
The analog part of a high-resolution A/D converter has been integrated in a compatible CMOS-JFET technology. The circuit, which forms a pulse-density modulator (PDM), can be operated at sample rates up to 12 MHz and reaches a peak SNR of 84 dB over a baseband of 20 kHz. This corresponds to approximately 14-bit A/D resolution. 相似文献
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《IEEE transactions on circuits and systems. I, Regular papers》2008,55(11):3383-3392
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综合利用到达方位角(DOA)和到达时间差(TDOA)等信息,建立单站无源定位系统的状态模型和观测模型,应用多维情形的二阶插值公式构造新型非线性滤波算法,而不需计算非线性函数的偏导,使得计算简化。仿真结果表明,用该算法可替代扩展卡尔曼滤波器(EKF)应用于单站无源定位中,能获得更为准确且收敛更快的定位结果。 相似文献
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A proposed instrument for deployment on next-generation Geostationary Operational Environmental Satellite (GOES) platforms is the Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR). A high-resolution full-Earth disk model has been developed to aid in the design of the instrument and to characterize sensor performance. A number of ancillary geophysical data fields are used as inputs into a radiative-transfer model that also accounts for the propagation and viewing geometries from a geostationary Earth orbit (GEO). The model produces high-resolution (10 km times 10 km) simulated full-Earth disk microwave images from GEO. The model is used as a tool to examine several critical aspects of GeoSTAR performance and design. Differential image processing is assessed as a means of mitigating the effects of the Gibbs phenomenon; its performance is found to be excellent, even with nonideal a priori information. The spatial resolution and precision of images generated at 50 GHz are evaluated. The magnitude of the highest spatial-frequency components sampled by GeoSTAR is found to be well above its minimum detectable signal. However, the differential image processing removes most of the high-frequency content, which is due to static high-contrast boundaries in the scene. Most of the residual high-frequency content lies at or below the instrument noise floor. 相似文献
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Jonggab Kil Jie Gu Kim C.H. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2008,16(4):456-465
This paper describes an interconnect technique for subthreshold circuits to improve global wire delay and reduce the delay variation due to process-voltage-temperature (PVT) fluctuations. By internally boosting the gate voltage of the driver transistors, operating region is shifted from subthreshold region to super-threshold region enhancing performance and improving tolerance to PVT variations. Simulations of a clock distribution network using the proposed driver shows a 66%-76% reduction in 3sigma clock skew value and 84%-88% reduction in clock tree delay compared to using conventional drivers. A 0.4-V test chip has been fabricated in a 0.18-mum 6-metal CMOS process to demonstrate the effectiveness of the proposed scheme. Measurement results show 2.6times faster switching speed and 2.4times less delay sensitivity under temperature variations. 相似文献
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A two-step high-precision Time-to-Digital Converter(TDC), integrated with a Single-Photon Avalanche Diode(SPAD), used for Time-Of-Flight(TOF) application, has been developed and tested. Time interval measurement is performed by the coarse counter and fine interpolator, which are utilized to measure the total periods and the residue time of the reference clock, respectively. Following a detail analysis of time precision and clock jitter in the two-step structure, the prototype TDC fabricated in GSMC 1P6M 0.18 μm CMOS Image Sensor(CIS) technology exhibits a Single-Shot Precision(SSP) of 11.415 ps and a dynamic range of 216.7 ns. In addition, a pixel of the chip occupies 100 μm×100 μm, and the measured Integral Nonlinearity(INL) and Differential Nonlinearity(DNL) are better than ±0.88 LSB and ±0.67 LSB, respectively. Meanwhile, the overall power consumption of the chip is 35 mW at 1.8 V power supply. Combined with these characteristics, the designed chip is suitable for TOF-based ranging applications. 相似文献
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用于高重复率激光测距系统的环状传递延时式时间数码转换器 总被引:1,自引:1,他引:0
本文报导一种创新的“环状传递延时式”单芯片时间数码转换器,由于线性度优异,测量“预时段”极短,故适用于高重复率光学飞时测距应用,例如扫瞄式三维测量激光雷达。使用一种简单的电路让循环脉冲第一周均回复其脉宽,使可转换的时间长度不会如以往装置因脉冲之前沿与后沿前进速度不同而受到限制。使用讥售可编程逻辑片所制造之原型样机。实验测得「之微分误差小于115psec,非线笥度小于0.31%,而最长可测时间只受限 相似文献
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当目标为宽带信号时,现有单站无源定位方法需要的参数难以获取。而时差和时差变化率是一种宽窄带都适用的观测量。因此,在分析时差和时差变化率所包含目标信息的基础上,建立了一种新的单站对宽带信号源的定位模型,并利用粒子滤波算法对该模型进行滤波处理。仿真实验表明了该方法的有效性。 相似文献
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无源时差定位系统的静止目标聚类检测算法 总被引:3,自引:0,他引:3
利用时差定位系统的定位误差特性,基于蚁群优化算法,提出了一种蚁群聚类检测算法,在不需要先验信息的情况下,实现了对静止目标的检测。实际数据测试结果表明蚁群聚类检测算法能够有效检测静止目标并估计目标位置,系统对静止目标的定位精度得到了显著改善。 相似文献
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Jan Riska Risto Kaunisto Petteri Alinikula Kari Halonen 《Analog Integrated Circuits and Signal Processing》2000,22(1):7-15
In this paper a fully monolithic on-chip local oscillator signal generation circuit is presented for eliminating the negative effect of coupling between bond-wires, package pins and output and input lines of the power amplifier output to the local oscillator input for direct conversion transmitters. The proposed circuit generates the local oscillator signal at frequencies 1710–1785 GHz which is harmonically uncorrelated from two input signals at 464 MHz and 1792–2088 MHz. The required building blocks are a frequency divider, a mixer and an active band-pass filter. Fully monolithic high frequency band-pass filters have not been available until recently, and the designed circuit is in fact one of the first applications reported for MMIC active filters in cellular phones. The circuit is designed with a 0.5 m GaAs MESFET technology and the performance is verified with on-chip measurements. 相似文献
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较详细介绍了一种基于三站时差定位体制的无源探测与跟踪雷达系统时差接收机的设计,该方案采用了信道化接收技术和混合门限信号检测方法 相似文献