An S/H circuit with parasitics optimized for IF-sampling

An IF-sampling S/H is presented, which adopts a flip-around structure, bottom-plate sampling technique and improved input bootstrapped switches. To achieve high sampling linearity over a wide input frequency range, the floating well technique is utilized to optimize the input switches. Besides, techniques of transistor load linearization and layout improvement are proposed to further reduce and linearize the parasitic capacitance. The S/H circuit has been fabricated in 0.18-μm CMOS process as the front-end of a 14 bit, 250 MS/s pipeline ADC. For 30 MHz input, the measured SFDR/SNDR of the ADC is 94.7 dB/68. 5dB, which can remain over 84.3 dB/65.4 dB for input frequency up to 400 MHz. The ADC presents excellent dynamic performance at high input frequency, which is mainly attributed to the parasitics optimized S/H circuit.     

微机异步串行通信技术及应用

本文介绍微机异步串行通信,对微机的内部电路不作改动,同时保证不丢失数据,可靠地实现数据交换。     

用于光通信的GaAs集成电路

介绍了用于 1 0 Gb/s光传输系统前端模块的超细栅 Ga As FET器件的制作技术以及制作的数 /模 IC芯片组     

模拟量及数字通信隔离电路

自动控制系统中,经常需要对模拟量的集中输入或集中输出及通过RS-485总线的主从式控制.如果不加以隔离,整个系统共用一个地,系统将工作在非常不稳定的状态,存在一定的安全隐患.本文介绍的模拟及数字通信隔离电路可以根本上解决上述问题.     

基于FPGA的串口通讯与VGA显示

本文介绍了基于FPGA（现场可编程门阵列）具有串口控制功能的VGA显示图像的设计实现方案。通过对该设计方案进行分析,可把本设计分成3个模块一一进行实现．这3个模块分别是串口发送模块、fifo存储模块、VGA显示模块。因此文中详细介绍了这3个模块详细设计方法,并在此基础上实现了3个模块协同工作以完成整个系统的功能。此设计...     

基于以太网的串行数字语音通信系统

针对当前广播对讲系统通信带宽受限、音质效果一般和扩展性差等问题,在对现有广播对讲系统进行分析比较的基础上,设计一种基于以太网的串行数字语音通信系统。阐述了系统的结构及软硬件设计,采用内嵌ARM内核的以太网控制器W7500P作为主控芯片,W5500和主控芯片构成双网络接口结构,同时使用语音编解码芯片VS1063实现模拟语音信号与数字音频信号的转换以及MP3格式数字音频信号的编解码功能,从而在保证语音质量的前提下降低语音信号对通信带宽的要求,以实现语音信号的高效传输。该系统连接简单、布线方便、成本低廉。实验测试表明,系统的语音质量、实时性和可靠性均符合现场使用的要求。     

PC机与DSP串行通信接口设计

详细讨论了全数字感应电机变频调速实验系统中PC机与DSP之间的通信接口设计，提出利用多线程技术实现上位机串口监视，利用虚拟菜单解决DSP侧的参数接收。     

基于串口通讯的雷神雷达数据解码

为提高空中交通管制系统的整体监视精度,需要对不同格式雷达数据融合.这首先需要先对各种不同格式的雷达数据进行解码.本文介绍了雷达报文的基本结构,以实际数据为例,对雷神雷达报文结构做了详细的阐述,并且给出了串口编程的实例,对串口得到的雷达数据解码.     

USB天地话音通信回路的检测方法研究

地面与飞船之间的话音通信是载人航天通信系统的关键组成部分。结合USB话音系统的组成和信息流程，提出了一种基于全态模拟器的新型通信回路检测方法。通过全态模拟器构成的天地话音通信回路能很好的检测整个载人航天通信系统的工作情况，并且能单独的经常性的检测单个测控站话音系统的工作情况，以确保话音回路畅通无阻，为载人航天任务的顺利完成提供重要保障。     

Optimal routing in circuit switched communication networks

Consideration is given to the optimal circuit routing problem in an existing circuit-switched network. The objective is to find circuit routing which accommodates a given circuit demand while maximizing the residual capacity of the network. In addition, the cost of accommodating the circuit demand should not exceed a given amount. Practical considerations require that a solution be robust to the variations in circuit demand and cost. The objective function for the optimal circuit routing problem is not a smooth one. In order to overcome the difficulties of nonsmooth optimization, the objective function is approximated by smooth concave functions. The optimization algorithm for the circuit routing problem is obtained as a limiting case of the sequence of optimal routing strategies for the corresponding smooth convex optimization problems, and the proof of its convergence to the optimal solution is given. An approach to calculating the optimal multicommodity flow is presented. The optimization algorithm efficiently handles networks with a large number of commodities, satisfies the robustness requirements, and can be used to solve circuit routing problems for large networks     

一种光通信同步电路的设计

介绍了一种光纤通信系统中基于FPGA的同步电路的原理,该电路实现了同步电路的全数字化.在MAX PLUS Ⅱ仿真环境下结合原理图和VHDL语言实现了位同步和帧同步电路的综合、仿真和配置.仿真结果表明,该电路能比较准确地恢复位同步和帧同步信号,性能优于传统的集成电路,具有较高的使用价值.     

Distributed NGD active circuit for RF-microwave communication

This paper is aimed to the investigation on innovative distributed negative group delay (DNGD) circuits for RF communication. Thanks to the analogy between the lumped and distributed circuits, NGD circuit topologies were identified. By using the S-parameter theory, analysis and synthesis methods of these topologies are proposed. The DNGD circuits developed are mainly comprised of a transistor combined with a series resistance ended by a stub. Then, synthesis relations enabling to determine the NGD circuit parameters from the desired NGD and gain values are established. As application, an active phase shifter (PS) operating independently with the frequency based on the cascade of PGD and NGD devices was synthesized. First, an NGD PS with transmission phase of (135 ± 5)° around 2.56 GHz over the bandwidth of about 1.02 GHz was obtained. Then, a two-stage DNGD PS exhibiting 90° with ±10° flatness from 4.1 GHz to 6.8 GHz was designed. The DNGD circuit presented can be used in various telecommunication areas notably for correcting RF/numerical signal delays in the RF-microwave analogue-digital devices.     

一种优化的卫星通信星际路由算法设计

在分析传统的链路——状态算法的基础上，提出了一种优化的卫星通信星际路由算法。该算法能够找出任意两颗卫星间通信的最佳路径集合，同时能够在链路质量容许的情况下，尽量避免通信链路切换的发生，从而较大地提高了系统性能。     

基于C#环境的单片机（89C51）与PC的串行通信

主要论述PC机与单片机之间实现异步串行通讯需要解决的问题以及如何利用C     

串行通信系统接口模块的设计与优化

串行通信系统以硬件资源简单、抗干扰强、易于实现等特点在数据通信及控制系统中得到了广泛的运用。本文以FPGA为实现平台,基于UART16550通信协议及工作原理完成高性能串行通信系统接口模块的完整功能设计与优化。采用三段式状态机设计方法和EDA优化、电路优化等优化手段完成设计及优化。优化后的设计系统时钟频率最高达到166MHz,功耗降低了63．9％,达到0．147W,且给出了典型波特率115200下的板级测试数据和Matlab分析结果。实验结果证明功能正确且稳定可靠。     

PLC与单片机之间的串行通信及应用

在工业自动化控制领域,较为重要的内容就是PLC和单元机之间的远距离控制,并且在自控系统设计过程中,经常遇到的难题就是PLC和单片机之间远距离通信,基于PLC和单片机两者优势充分发挥的基础上,能够确保PLC和单片机之间串行通信的良好实现。本文基于实际情况的基础上,通过对现阶段较为常见且应用较为广泛的单片机进行分析探讨。     

TMS320F2812型数字信号处理器与PC的串行通信

讨论TMS320F2812与PC之间的串行通信方案，给出TI公司的TMS320F2812型DSP和Maxim公司MAX3160型收发器的硬件接口电路，以及在此基础上使用中断和查询方法实现的串行通信软件流程，同时给出DSPSCI的初始化、发送和接收数据程序代码。     

An all-optical method of developing data communication system with error detection circuit

The basic criterion of data communication is that received data should exactly be the replica of the transmitting data. If any error is introduced in the received data, then data transmission should be stopped immediately. In this article the authors have developed an all-optical method of data communication system with error detection mechanism that works with frequency encoded data. Basic building blocks of the proposed data communication scheme are parity generator and parity checker which are developed from all optical XOR logic gates. Simulation results testify the feasibility of the proposed scheme. These logic gates are developed exploiting nonlinear polarization rotation based frequency conversion and switching character of semiconductor optical amplifiers. The scheme with frequency encoded data, high speed of frequency conversion and polarization switching action of semiconductor optical amplifier offers secure, error free, faster data communication network.     

基于红外光通信电路的设计与制作

本文使用集成运放TDA2822M、红外对管作为收发器件,设计并制作出了红外载波发射电路和接收电路,实现了有限距离的红外光通信。该装置能够实现在3.0m距离范围内,接收端可接收不失真的音频信号,同时,通过监测电路可实时监测到发射端和接收端的信号情况,便于将电路调整到最佳运行状态。     

一种综合型通信接口转换电路的设计

信息技术不断发展,许多控制系统在设计研发过程中需要通过通信接口完成指令的传达、信息的采集与各项控制显示功能.但不同的工作单元采用的通信接口不同,因此需要对各工作单元做通信转换后,方可正常通信.针对不同的通信接口,设计一种综合的隔离RS232、RS232、RS485通信转换电路,使得这几种通信接口在通信时只使用同一转换模...