查询词典 analog to digital converter

Only oneA/D converter is needed to complete complex quadrature translation and digital downconversion, get in-phase component and quadrature component in digital field, and also,after intra-pulse compression is done, the signal-to-noise ratio is raised, and inter-pulsecompression is done in digital field, and finally, high range resolution profile is got.Two-step stretch processing method for MMW high-resolution RADAR is presented.

计算并优化了毫米波雷达中频信号带通采样的最佳采样频率，应用现有的集成电路技术实现对中频信号的直接采样、用一个A／D转换器在数字域完成复数正交变换，在数字域完成下变频、获得同相信号和正交相信号、完成对子脉冲的脉内压缩、完成对脉内压缩信号的第二次脉间压缩，从而获得高分辨一维距离像。

Its final target is to fully digitize the analogue receiver. The all digital receiver not just means digitizing every unit of the analogue receiver, but is a new receiver architecture. The two outstanding characters of this new architecture is: 1 It uses a high stable oscillator to generate a fixed frequency source. And both the sample signal and the local carrier required are obtained from it. 2 Once the received signal has been sampled by a high speed A/D converter, some digital signal processing algorithms will be used to realize all further processes, such as digital down-converting, match filtering, symbol timing, channel equalizing, carrier synchronizing, demodulating and decoding.

全数字接收机并不是简单地将传统的模拟接收机中所有的部件数字化的结果，而是一种全新的接收机体系结构，这种新的体系结构具有两个最为突出的特点：1）采用高稳定度晶体振荡器产生一个固定的本地频率源，接收机中所需的采样时钟信号和本地载波均从这一固定频率源得到；2）接收信号一旦经过高速模数转换后，余下的工作如频率变换、匹配滤波、定时同步、信道均衡、载波同步、符号解调、判决与译码等全部由数字信号处理算法来实现。

The data of the pre and post reconstruction of microwave time comparison system is collected and processed. The performance of one-way time transfer of previous system, the digital channel and the analog channel of the reconstructed system are analyzed, and the performance of two-way time comparison of the analog channel and the performance of GPS CV time comparison are analyzed too.

对改造前后的微波时间比对系统和GPS共视比对系统进行数据采集、处理，分析了改造前微波时间比对系统的单向时间传递性能，改造后的数字微波时间比对系统数字通道和模拟通道的单向时间传递性能，模拟通道的双向时间比对性能及GPS共视系统的时间比对性能。

The development of MSCIS mainly includes the following two parts: the cards and the software running on the communication computer. There are five types of cards, communication card, control card, analog output card, analog input card and digital input/output card.

MSCIS接口系统的研制工作主要包括两大部分：系统硬件板卡（包括通信卡、控制卡、模拟量输入卡、模拟量输出卡和数字量输入输出卡）的研制和通信计算机软件研制。

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

10 Multifunction Intelligent DAQ using LabVIEW FPGA, 8 analog inputs, independent sampling rates up to 200 kHz, 16-bit resolution,±10 V,8 analog outputs, independent update rates up to 1.0 MHz, 16-bit resolution,±10 V,96 digital lines configurable as inputs, outputs, counters, or custom logic atrates up to 40 MHz,User-defined triggering, timing, and onboard decision making with 25 ns resolution,1M gate reconfigurable I/O FPGA for parallel processing power

2.10 使用LabVIEW FPGA模块的可重新配置多功能I/O，8路模拟输入、200 kHz同步采样率、16位分辨率、±10 V，8路模拟输出、1 kHz同步采样率、16位分辨率、±10 V，96条可配置的数字线，具有40 MHz输入、输出、计时器或自定义功能，25 ns分辨率的可配置触发、定时、板载决策，1百万门可重新配置I/OFPGA，带有82 kB嵌入式RAM

Analog part includes sample and hold circuit, current comparator and digital analog convert.

类比部份为：取样保持电路、电流比较器、数位类比转换器。

Doesn't be processed and direct is adopted analog-to-convert,the dyn amic range of analog-to-digital converterin data acquisition circuit can't match the need of GPR system and the problem will affect the exploration depth and resolution of GPR.

探地雷达回波信号具有动态范围大、频带宽等特点，如果不对回波信号进行处理直接进行A／D转换，则会出现动态范围不匹配的问题，严重影响雷达的探测深度和分辨率。

We are applying to support high quality analog TV measurements and analog/digital TV transmitter and transposer.

为中国用户提供高端的模拟电视测试设备以及模拟、数字电视发射及传输设备。

Lisch is applying to support high quality analog TV measurements and analog/digital TV transmitter and transposer.

LISCH为中国用户提供高端的模拟电视测试设备以及模拟、数字电视发射及传输设备。

Although translator has turned from being a crystal ball by which the original culture can unrestrainedly penetrate to another crystal ball by which the target culture can freely traverse, the translator's personal embodiment, in the process of cognitive act, are still absent in translation studies. Translators are still subjects without body or simply disembodied subjects.

译者虽然由原语文化可以自由穿透的玻璃球变成了译语文化可以自由穿越的玻璃球，但译者认知过程中的个体体验在翻译研究中依然缺席，译者依然仅仅是一个没有躯体体验的主体。

Chillingly, he claimed our technology is 'not nearly as sophisticated' as theirs and "had they been hostile", he warned 'we would be been gone by now'.

令人毛骨悚然的，他声称我们的技术是'并不那么复杂，像他们一样，和"如果他们敌意"，他警告说，'我们将现在已经过去了。