为了在CDMA系统中更好地应用QDPSK数字调制方式，在分析四相相对移相（QDPSK)信号调制解调原理的基础上，设计了一种QDPSK调制解调电路，它包括串并转换、差分编码、四相载波产生和选相、相干解调、差分译码和并串转换电路。在MAX+PLUSⅡ软件平台上，进行了编译和波形仿真。综合后下载到复杂可编程逻辑器件EPM7128SLC84-15中，测试结果表明，调制电路能正确选相，解调电路输出数据与QDPSK调制输入数据完全一致，达到了预期的设计要求。 Abstract: In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.
上传时间： 2013-10-28
上传用户：jyycc
Proteus实例集锦(包括电路图.仿真程序,各种各样的电路):4x4键盘，51单片机12864大液晶屏proteus仿真，8253可编程定时器计数器，窃听器(使用PROTEUS串口例子)V1.0，电子琴和倒计时播放音乐，电压电流转换电路，单片机设计2008奥运会，Schematic模型创建方法等资料。
上传时间： 2013-10-10
上传用户：181992417
本设计实际上是将被测模拟量转换为数字量，并进行实时数字显示，主要由以下几部分构成：量程转换电路、AC-DC转换电路、3位半A/D转换单元电路、基准电源单元电路、译码驱动单元以及数码管显示单元。其中A/D转换器选用三位半MC14433，基准电源选用MC1403，译码驱动器则MC14511，另加四个共阴极LED发光数码管。
上传时间： 2013-12-24
上传用户：thinode
模拟数字转换，转换电路，模拟量，数字量，8位数字量输出
上传时间： 2017-09-18
上传用户：ruan2570406
电压比较器加法电路减法电路三角波发生器同相比例放大器电路集成运放电路测试Multisim仿真源文件，Multisim10以上版本可打开运行三角波发生器.ms10三角波发生器.ms10 (Security copy)仪表放大器.ms10仪表放大器.ms10 (Security copy)低通滤波.ms10 (Security copy)低通高通带通带阻滤波.ms10减法电路.ms10减法电路.ms10 (Security copy)加法电路.ms10加法电路.ms10 (Security copy)单极性到双继续转换电路.ms10单极性到双继续转换电路.ms10 (Security copy)双极性到单极性转换电路.ms10双极性到单极性转换电路.ms10 (Security copy)反相比例放大器电路.ms10反相比例放大器电路.ms10 (Security copy)同相比例放大器电路.ms10同相比例放大器电路.ms10 (Security copy)文氏桥电路.ms10文氏桥电路.ms10 (Security copy)电压比较器设计.ms10电压比较器设计.ms10 (Security copy)采样保持电路.ms10采样保持电路.ms10 (Security copy)
标签： 电压比较器
上传时间： 2021-10-27
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DC_DC转换器的外围器件的选用外部器件的选用需要注意的是外围器件的选用对DC/DC转换电路有很大的影响。对于DC/DC标准转换电路中的外部器件的使用，请参考以下提
标签： DC_DC转换器
上传时间： 2021-12-09
上传用户：zhanglei193
电学中的测量技术涉及范围非常广,电流测量在电学计量中占有非常重要的位置。如何精确地进行电流测量是精密测量的一大难题。传统的电流检测电路多采用运算放大芯片与片外电流检测电路相结合的方式,电路集成度很低,需要较多的接口和资源才能完成对电路的检测。本文把所有电路部分都集成在一块芯片上,包括检测电阻,运算放大器电路及模拟转数字转换电路,从而在电路内部可以进行电流检测,使电路更好的集成化。前置电路使用二级共源共栅结构的运算放大器,减小沟道长度调制效应造成的电流误差。10位SAR ADC中采用电容驱动能力强的传输门保证了模数转化器的有效精度。比较器模块采用再生锁存器与迟滞比较器作为基础单元组合解决精密测量的问题。本设计可以作为嵌入芯片内的一小部分而检测芯片中的微小电流1mA~100mA,工作电压在1.8v左右,电流检测精度预期达到10uA的需求。The measurement technology in electricity involves a wide range,and current measurement plays a very important position in electrical measurement.How to accurately measure current is a big problem in precision measurement. The traditional current detecting circuit adopts the combination of the operational amplifier chip and theoff-chip current detecting circuit, The circuit integration is very low, and more interfaces and resources are needed tocomplete the circuit detection.This topic integrates all the circuit parts into one chip, including detection resistance, operational amplifier circuit andanalog to digital conversion circuit. Highly integrated circuit makes the external resources on the chip more intensive,so that current detection can be carried out inside the circuit, so that the circuit can be better integrated. Thefront-end circuit of this project uses two-stage cascade operational amplifier and cascade tube to reduce the currenterror caused by channel length modulation effect. In 10-bit SAR ADC, the transmission gate with strong capacitivedriving ability ensures the effective accuracy of the analog-to-digital converter. Comparator module uses regenerativelatch and hysteresis comparator as basic unit to solve the difficult problem of precision measurement. This topic can beused as a small part of the embedded chip to detect the micro-current in the chip 1 mA~100 mA, the working voltageis about 1.8v, and the current detection accuracy is expected to reach the requirement of 10 uA.
上传时间： 2022-04-03
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为了提高超高频RFID系统中阅读器在低信噪比的情况下仍具有较高的识别能力,提出一种基于FPGA系统结合软件无线电方法实现超高频RFID射频前端电路方案。超高频射频识别系统必须符合EPC Class 1generation 2标准,所设计的电路系统以Xilinx公司的XC6SLX16-2CSG324FPGA芯片为硬件基础,将数字基带调制解调和中频滤波电路在FPGA系统中设计实现,重点阐述了射频前端电路的设计结构、AD/DA转换电路,以及数字滤波器的设计。实验结果表明,所设计的超高频RFID阅读器简化了前端电路系统结构,提升了稳定性,增强了抗干扰能力。该电路系统在信噪比较低的情况下,能够较好地实现915MHz频率的射频接收和发送。In order to improve the reader UHF RFID system still has a higher ability to identify,in the case of low signal-to-noise ratio.The UHF RFID systems must comply with EPC Class 1 generation 2 standard.In this paper,the design of the circuit system based on Xilinx＇s XC6SLX16-2CSG324 FPGA chip,and presents UHF RFID RF front-end circuit with software radio based on FPGA system.Digital baseband modem and IF filter circuit is designed and implemented in the FPGA system,and focused on designing the structure of the RF front-end circuit,AD/DA conversion circuits,and digital filter.Experimental results show that the UHF RFID reader de...
标签： 915mhz 超高频 rfid 阅读 射频 前端 电路 设计
上传时间： 2022-04-17
上传用户：shjgzh
本文提出基于AD2S1210的旋变信号转换电路,给出了具体的电路实现方法和配置方法.相比以往的RDC方案,本系统具有精度高,设计灵活,可靠性高等特点,可广泛应用于各种伺服系统中.In this paper, the switching signal conversion circuit based on ADS1210 is proposed, and the specific circuit implementation and configuration method are given. Compared with the previous RDC scheme, this system has the characteristics of high precision, flexible design and high reliability, and can be widely used in various servo systems.
标签： ad2s1210
上传时间： 2022-05-04
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以微处理器为控制核心,设计了一种可通过手机等移动智能终端控制的,应用于生化检测中三电极体系的恒电位仪式读取电路系统。该系统集恒电位仪电路、滤波电路、I/V转换电路、蓝牙通信控制终端等于一体,小型便携,无线遥控,操作方便。测试结果与LK2006A测试结果对比,绝对误差小于0.04%。
上传时间： 2022-05-11
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