共查询到19条相似文献,搜索用时 234 毫秒
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基于光相位调制的核信号读出方法将探测器信号调制进光纤中,并使用光纤作为模拟信号的传输介质。在该读出方案中,调制驱动模块负责载波信号的产生及放大,是该方案读出电子学系统的重要组成部分。为了产生低相位噪声,幅度大且幅度可调的载波信号,本工作提出了基于锁相环的载波产生电路和基于MMIC射频放大器的载波放大电路的设计方案,该方案结构简单,尺寸小,性能优异。对载波产生电路使用了ADIsimPLL仿真软件进行了环路滤波器的设计和仿真,同时也对载波放大电路使用ADS仿真软件进行了设计和仿真,并在实验室条件下进行了测试。测试结果表明,输出26 dBm载波信号相位噪声好于–110 dBc/Hz@100 kHz,能够用于信号解调。 相似文献
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新型四倍频光生毫米波矢量信号调制技术 总被引:1,自引:0,他引:1
提出一种基于双并联马赫-曾德尔调制器(MZM)的新型四倍频光生毫米波技术,并用于矢量信号调制。传统的四倍频调制技术,由于数据信号同时调制到+2,-2阶边带上,拍频检测后两个边带上数据信号会产生相位叠加,只适用于不归零码(NRZ)等强度调制格式。提出的矢量信号调制技术将数据信号调制在一个-1阶边带上,另一个+3阶边带不携带数据,在拍频检测后幅度和相位信息被正确保留。同时,四倍频模块降低了传输过程中对电和光器件的带宽需求。理论分析和仿真结果表明,通过此方法产生的携带在60GHz载波上的6.25×108 symbol/s的四相相移键控(QPSK)信号,经过20km单模光纤传输后,误差向量幅度(EVM)损耗可以忽略。 相似文献
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多阶游程存储是一种不改变光学系统而显著提高光存储容量和数据传输率的新方法.介绍了光致变色多阶游程存储原理和实验系统.提出了基于光致变色原理的多阶游程存储数学模型,该模型反映了记录符反射率与曝光功率、曝光时间之间的非线性关系,并在此基础上确定了光致变色多阶游程存储的写策略.基于650nm光致变色材料进行了4阶游程存储的动态实验.结果表明,实验中采用的650nm光致变色材料可用于多阶游程存储,采用的写策略能够有效地使记录信道线性化,利于采用适合线性系统的信号处理方法.
关键词:
多阶游程
光致变色
光存储
写策略 相似文献
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Back-n是中国散裂中子源(CSNS)的反角中子束线,适用于精密核数据的测量。该装置的谱仪读出电子学采用共性化设计方法,利用高速波形数字化技术精密采集探测器输出信号波形。为完成对两通道、1 GSps,12 bit采样数据的读出和板载外设的控制,可以使用一种基于FPGA的高速数据实时读出方法。该方法不仅实现了数据接收、缓存上传等通用需求,还通过软件配置满足了实时触发处理等针对特定物理实验的特性需求。此外,FPGA的灵活使通过固件更新支持新实验或添加新功能成为可能。测试结果表明,该方法能够适应Back-n波形数字化模块高速数据读出的需求,峰值处理能力可达24 Gbps,符合物理实验需求。目前,基于实时读出方法实现的波形数字化模块已完成中子源谱仪实验现场的安装,工作稳定。Back-n is a back-streaming beam line at China Spallation Neutron Source, which is suitable for measure nuclear data precisely. The readout electronics of the spectrometers at this facility adopts general-propose design method, using high-speed waveform digitizing technology to record the detector output signal accurately. To read out two channels, 1 GSps, 12 bit sample data and control on-board devices, the real-time readout method of high-speed data based on FPGA technology can be considered. The method not only realizes the general requirements of the data upload, but also processes real-time triggers according to experiments via configuration. In addition, due to the flexibility of FPGAs, new experiments or new features can be supported through firmware updates. The test results show that the method is suitable for the high-speed data readout of field digitizing module at Back-n and peak capacity reaches up to 24 Gbps, which meets the requirements of the physical experiment. The field digitizing modules based on this method were installed at Back-n and work normally. 相似文献
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An innovative multilevel read-only recording method is proposed. In this method, a short pit/land is deliberately inserted to the original land/pit. This modifies the wave-shape of readout signM. Taking the wave-shape as the symbol of level detection, a signal wave-shape modulation (SWSM) multilevel method is realized. This method is carried out and validated on the DVD read-only manufacture and readout system. A capacity of 15 GB can be expected, and a bit error rate of 10-4 is achieved. The capacity can meet the demand of high definition movie publication. This method also provides a potential multi-level solution for other storage formats and systems. 相似文献
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Polarization readout analysis for multilevel phase change recording by crystallization degree modulation
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Four different states of Si15Sb85 and Ge2Sb2Te5 phase change memory thin films are obtained by crystallization degree modulation through laser initialization at different powers or annealing at different temperatures. The polarization characteristics of these two four-level phase change recording media are analyzed systematically. A simple and effective readout scheme is then proposed, and the readout signal is numerically simulated. The results show that a high-contrast polarization readout can be obtained in an extensive wavelength range for the four-level phase change recording media using common phase change materials. This study will help in-depth understanding of the physical mechanisms and provide technical approaches to multilevel phase change recording. 相似文献
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Yoshinori Honguh 《Optical Review》1995,2(1):14-19
A noise power spectrum estimation method is presented for optical disk readout signal influenced by dust on the substrate. The noise due to dust has been modeled using geometrical optics and assuming the Poisson distribution for the dust particles. The noise power spectrum consists of two components: one comes from the effect of individual dust particles passing across the light beam, and the other comes from the effect of overlapping area of a particle and the inverted image of another particle. The feasibility of a thin-substrate optical disk was studied using this model. Dust will not have a serious effect on the readout signal when a 0.6 mm-thick substrate is used in place of the conventional 1.2 mm-thick substrate. 相似文献
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在磁通调制超导量子干涉器件(SQUID)的读出电路中, 匹配变压器具有放大信号和阻抗匹配的功能, 是实现SQUID低噪声读出的关键元件. 利用模拟SQUID电路对匹配变压器进行性能测试, 研究了不同绕制匝数变压器的传输特性, 确定最佳绕制匝数比. 在变压器拾取SQUID电压信号的耦合网络中, 研究了不同电容对变压器传输特性的影响, 实现了变压器耦合网络参数的匹配和优化. 室温下匝数比为1:20的匹配变压器在匹配电容C=1μF时, 输出源电压增益为21.2, 带宽范围可达到210 kHz. 最后在基于磁通调制式DC SQUID读出电路中, 对匹配变压器的工作性能进行了评估与验证.
关键词:
超导量子干涉器件读出电路
匹配变压器
低噪声
传输特性 相似文献
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A high dynamic range readout unit for a calorimeter 总被引:1,自引:0,他引:1
A high dynamic range readout system, consisting of a multi-dynode readout PMT and a VA32 chip, is presented. An LED system is set up to calibrate the relative gains between the dynodes, and the ADC counts per MIPs from dynode 7 are determined under cosmic-ray calibration. A dynamic range from 0.5 MIPs to 1×105 MIPs is achieved. 相似文献
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本文对读出原理、像差要求、图谱质量进行深入研究,进而对读出技术进行深度整合与简化,实现光读出FPA红外成像系统小型化、轻量化、集成化。首先,从FPA的热-机械效应出发,介绍了光读出FPA红外成像系统的工作原理;然后,针对通常采用的光读出FPA红外成像系统体积大、重量大、结构复杂缺陷,提出了高集成度的新型光读出系统;接着,在分析讨论读出光路像差容限、特点的基础上,对以异形棱镜为核心元件的光读出系统进行了具体的光学仿真设计;最后,设计了集光、机、电、软技术的集成式光读出FPA红外成像系统。对系统样机测试结果表明:在确保成像性能的前提下,光读出FPA红外成像系统的体积减小到175 mm×83 mm×105 mm。以异形棱镜为核心元件的光读出技术,在满足成像精度和灵敏度的前提下,可减小读出系统的复杂程度,有效降低了光读出FPA红外成像系统的体积和重量,从而促进光读出FPA成像系统的工业化应用。 相似文献
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针对当前四频差动激光陀螺(DLG)读出系统结构复杂、易受温度影响等问题,对现有读出系统进行了改进,设计了使用电子信号处理代替光学信号处理来分离左、右旋陀螺信号的新型读出系统。通过对一个DLG同时使用新旧两套不同的读出系统进行测试,得到了相同的测试结果,表明电子信号处理和光学信号处理在分离左、右旋陀螺信号方面是等效的。在此基础上,首先使用模数转换器对DLG的光电转换信号进行采样,然后进行了数字信号处理,并研制出了全数字化读出系统。新型读出系统不使用四分之一波片和偏振片等光学元件,具有温度稳定性好、结构简单、全数字化等优点,有利于四频陀螺性能的提高和批量生产。 相似文献
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The KM2A(one kilometer square extensive air shower array) is the largest detector array in the LHAASO(Large High Altitude Air Shower Observatory) project. The KM2 A consists of 5242 EDs(Electromagnetic particle Detectors) and 1221 MDs(Muon Detectors). The EDs are distributed and exposed in the wild. Two channels, anode and dynode, are employed for the PMT(photomultiplier tube) signal readout. The readout electronics designed in this paper aims at accurate charge and arrival time measurement of the PMT signals, which cover a large amplitude range from 20 P.E.(photoelectrons) to 2×10~5 P.E. By using a "trigger-less" architecture, we digitize signals close to the PMTs. All digitized data is transmitted to DAQ(Data Acquisition) via a simplified White Rabbit protocol.Compared with traditional high energy experiments, high precision of time measurement over such a large area and suppression of temperature effects in the wild become the key techniques. Experiments show that the design has fulfilled the requirements in this project. 相似文献