一种适用于中频接收机的具有75dB动态范围的100MHz带通$\Sigma \Delta$调制器

本文介绍了一款适用于中频接收机的四阶开关电容带通$\Sigma \Delta$调制器,采样频率为100MHz。为优化谐振器的性能,文中提出了考虑运算放大器非理想特性后谐振器的传输函数。本文设计的调制器采用0.13-um标准CMOS工艺,在25MHz附近200KHz信号带宽内测得的SNDR和DR分别为68dB和75dB。调制器工作在1.2V电源电压下,总功耗为8.2mW。     

基于C#和SQL Server的信号接收机自动校准系统软件设计与实现

为保证信号接收数据的准确性,提高测试校准工作的自动化水平,本文基于C#与SQL Server对信号接收机自动校准系统软件进行了设计。基于多线程设计系统程序,提高了测试校准效率;基于双缓存技术绘制测试数据波形,解决了波形显示闪屏的问题;采用SQL Server数据库存储测试数据和仪器控制指令,实现高效数据存储和管理;运用测试报告自动生成技术实现校准证书和原始记录的自动生成。该自动校准系统设计对提高信号接收机校准工作效率,增强设备计量保障能力具有较强的应用价值。     

一种基于SiGe BiCMOS工艺的单片集成光接收机前端放大电路

基于0.13μm SiGe BiCMOS工艺,设计了一种25 Gbit/s的光接收机前端放大电路单片集成的放大电路。该电路实现了光接收机前端放大电路的单片集成,并采用带反馈系统的跨阻放大器、电感峰化、自动增益控制电路等设计有效提高了增益、带宽和系统稳定性。经仿真与测试,该设计增益达到69.9 dB,带宽为19.1 GHz,并在工业级芯片工作温度(-40℃~+85℃)下带宽误差不超过0.1%。该芯片工作时需要的供电电流为45 mA,功耗为81 mW,信号抖动RMS值为5.8 ps,具有良好的性能和稳定性。本设计提供了一种能够适用于100 Gbit/s(25 Gbit/s×4线)光互连系统的设计方案,具有广泛的应用前景。     

Simple Detection Based on Soft‐Limiting for Binary Transmission in a Mixture of Generalized Normal‐Laplace Distributed Noise and Gaussian Noise

In this letter, a simplified suboptimum receiver based on soft‐limiting for the detection of binary antipodal signals in non‐Gaussian noise modeled as a generalized normal‐Laplace (GNL) distribution combined with Gaussian noise is presented. The suboptimum receiver has low computational complexity. Furthermore, when the number of diversity branches is small, its performance is very close to that of the Neyman‐Pearson optimum receiver based on the probability density function obtained by the Fourier inversion of the characteristic function of the GNL‐plus‐Gaussian distribution.     

TD-SCDMA集群系统中部分宏分集组网前向容量分析

TD-SCDMA集群小区使用宏分集技术可以有效的克服大尺度衰落,保证信号质量。本文首先分析了在没有任何措施的前提下进行宏分集组网,但前向容量会随着宏分集基站数的增多而减少。在分析容量损失原因的基础上,我们进一步提出在终端利用Rake接收机对各路信号进行同步、相位调整,再进行最大比值合并,然后发送给用户,由此,前向容量大大提高。     

广州地铁盾构到达密闭接收装置技术应用

广州地铁南浦站～洛溪站区间盾构到达端头地质情况差,存在盾构到达端头加固范围管线拆改困难、加固质量难以保证等问题.施工中,首次制造并使用了盾构到达密闭接收装置技术,该装置主要基于平衡到达理念,制造一个直径和长度比盾构略大的密闭钢筒状结构与硐门密闭连接,通过在结构内灌入填充物2台达到与土层平衡的压力,模拟盾构在土体中的掘进,使盾构直接通过硐门,安全进入接收装置.该技术保证了2台盾构成功接收,具有适用性广、加固简单、工期短、安全可控等优点.     

GNSS信号接收机的构件初识──GNSS导航信号的收发问题之十

GNSS信号接收机是GNSS导航卫星的用户设备,是实现GNSS卫星导航定位的终端仪器。它是一种能够接收、跟踪、变换和测量GNSS卫星导航定位信号的无线电接收设备,既具有常用无线电接收设备的共性,又具有捕获、跟踪和处理弱达3.5E-16W~2.5E-17W卫星微弱信号的特性。为此,GNSS信号接收机的构件必须满足这种捕获、跟踪和测量GNSS信号的需求。     

Transimpedance amplifier with a compression stage for wide dynamic range optical applications

A high dynamic input transimpedance amplifier was implemented in 130 nm CMOS technology. The proposed TIA is an inverter with a diode connected NMOS and a gate controlled PMOS loads which is cascode connected with the inverter. The square law compression NMOS increases the input photocurrent up to 10 mA. The TIA has an integrated input referred noise current of 135 nA, 227 MHz bandwidth. The TIA shows a transimpedance gain of 59 dBΩ and a 97 dB dynamic range. The TIA consumes 2.3 mA from 1.5 V voltage supply.     

Theoretical performance analysis of radio frequency fingerprinting under receiver distortions

Radio frequency fingerprinting (RFF) is used to uniquely identify individual emitters by exploiting the radio frequency characteristics, which are originated from transmitter imperfections. The theoretical performance is analyzed to evaluate the feasibility of RFF with channel noise and receiver imperfections. The distortions from oscillators and analog‐to‐digital converter (ADC) are considered, and a RFF signal model describing the discrepancies of transmitter imperfections, channel noise, and receiver distortions are constructed. A likelihood ratio test algorithm for RFF is proposed to analyze the theoretical performance. The upper and lower bound of theoretic performance is derived through the analysis of the likelihood ratio test statistic, which enlightens how to design a “just enough” receiver to meet the demands of RFF. The simulation results are in agreement with the theoretical evaluation. Copyright © 2013 John Wiley & Sons, Ltd.     

卫星导航接收机信噪比分析

用噪声温度的概念给出了卫星导航接收机射频前端的噪声,分析A／D转换器和码环不同步带来的噪声。根据上述结论设计的卫星接收机的各项技术指标都达到了先进水平,验证了本文的合理性和正确性。