影响IFM接收机测频精度因素的分析

根据瞬时测频接收机基本原理,介绍和分析了影响瞬时测频接收机测频精度的主要因素,并根据瞬时测频接收机系统应用提出了提高接收机的测频精度一些有效的处理方法,其方法在瞬时测频接收机系统中得到应用和验证,达到了工程的要求。     

一种超小型化瞬时测频接收机设计

现代电子战设备的发展方向是小型化、便携性、高性能,而瞬时测频接收机小型化的前提是元器件的小型化,由于芯片集成已经发展得很成熟,所以瞬时测频接收机前端微波器件的小型化是实现超小型化瞬时测频接收机的关键。文章先对LTCC技术特点进行简要介绍,提出一种基于LTCC技术的超小型化瞬时测频接收机设计,通过与采用传统微波传输线体制相关器组件的瞬时测频接收机进行性能对比,该超小型化瞬时测频接收机在体积、重量方面有明显的优势。     

一种具有温度补偿的瞬时测频接收机的设计与实现

本文通过研究和分析温度对瞬时测频接收机测频误差的影响,改变了传统电缆恒温处理设计方案,在测频接收机中加入一温度补偿模块,实现对温度引起的测频误差的校正.并在硬件上实现了该测频系统.其中测频范围为2 GHz,通过测试,精度达到≤1 MHz(r.m.s),完全满足设计要求.     

宽带大动态瞬时测频接收机的设计与实现

论述了宽带大动态瞬时测频接收机的工作原理,在理论和实践的基础上,介绍了宽带大动态瞬时测频接收机的设计与实现。通过性能测试证明文中介绍的测频接收机技术先进可靠,结构简单合理。     

基于AD采样量化编码体制的IFM设计

瞬时测频(IFM)接收机能精确地测量雷达信号的载频,对单个脉冲或短暂脉冲群具有100%的截获概率,以及高精度和瞬时覆盖带宽宽的特点,是现代电子战系统中的重要组成部分。主要介绍了采用AD采样量化编码体制的工作原理以及相应的实现方式,通过与传统电阻环极性量化编码体制瞬时测频接收机进行性能对比,基于AD采样量化编码体制的瞬时测频接收机在鉴相器数量、印制板尺寸、测频误差方面明显优于传统电阻环极性量化编码体制的瞬时测频接收机。     

瞬时测频误差

瞬时测频技术是瞬时测频接收机的核心关键,对瞬时测频的误差产生原因进行了分析,并对误差来源进行了详细阐述,提出了能够减小误差的可行方案。     

基于AD8302的瞬时测频接收机

为了简化瞬时测频(IFM)接收机的结构、提高集成度,设计了采用AD8302为核心的IFM接收机,并分析了该测频接收机的灵敏度、动态范围、测频精度等关键指标。最后制作了实验系统对该IFM接收机的可行性进行了验证,实验结果表明采用AD8302实现的IFM接收机可以提高测频精度,简化接收机结构。     

750波导引起测频偏差原因分析及解决方案

在某侦察设备中使用750波导引起宽带瞬时测频接收机测频误差偏大。分析了产生原因,并提出两种解决方案：延长测频接收机的采样时间;采用截止频率更低的650波导。     

瞬时测频接收机的连续波干扰技术研究

雷达信号频率是接收机进行信号分选的一个重要参数。分析了比相法瞬时测频(IFM)接收机的组成和测频原理,针对同时到达信号对IFM接收机测频结果的影响,从雷达反侦察角度出发,提出用步进频率连续波信号对接收机进行干扰来破坏其正确测频结果,并进行仿真分析验证了干扰效果。     

如何测量同时到达信号

对于数字式瞬时测频接收机,在目前雷达对抗和反对抗日益激烈的环境下,测量同时到达信号和脉冲重叠信号已成为当务之急.提出一种改进瞬时测频接收机的方法,使其能够抗连续波捕获,测显同时到达信号.     

新型定向耦合器在DIFM中的应用

介绍了一种新型微带定向耦合器的原理和设计方法，给出了采用这种新型定向耦合器的微波鉴相器设计。并得到其误差性能的测试方法和测试结果。最后。介绍了一种基于这种微波鉴相器的瞬时测频接收机，并给出了用于温度补偿和误差校正的自动快速测试方法。     

温度传感器DS1621在电子战接收机中的应用

在现代电子战中,接收机的工作环境往往比较恶劣,由各种模拟器件的温度漂移特性而导致接收机性能指标下降的现象普遍存在,对接收机进行温度补偿是必要的。文中介绍一种温度传感器DS1621芯片,具有较小的体积和较高的温度测量精度,基于I2C总线数据传输机制,在某型号信道化接收机温度补偿系统中得到的较好的应用,并给出了部分VHDL程序代码和实验结果。     

被动雷达导引头的关键技术研究

本文介绍了反辐射导弹被动雷达导引头的几个关键技术，提出了一种能快速捕获目标的宽带数字瞬时测频方法，同时对宽带多路测向系统的性能进行了分析，并给出了主要模块的实现方案。     

Design and analysis of a high-sensitivity optical receiver forSONET OC-12 systems

In this paper, we will present the design and analysis of a high-performance lightwave receiver front end for SONET OC-12 applications. The receiver is designed to be operated with the standard +5 V and -5.2 W power supplies, and can be incorporated into an existing commercially available full receiver package. The full receiver achieves a sensitivity of better than -44 dBm at a bit error rate of 1×10 ^-9 over the whole operating temperature range of 0°-65°C. The construction and performance of the receiver will be discussed in detail in this paper. As a part of the process of design consideration, we will also discuss the S-over-X measurement, a characterization procedure for ISI (intersymbol interference) simulation and eye-opening estimation, frequently used for SONET or SDH subsystems yet not often discussed in the literature. The interpretations of the results of the S-over-X measurement are sometimes very misleading. Examples included in this paper will help the lightwave subsystem vendors and customers to have a better perspective on the S-over-X measurement process     

A 250-MHz BiCMOS receiver channel with leading edge timing discriminator for a pulsed time-of-flight laser rangefinder

An integrated receiver channel of a pulsed time-of-flight (TOF) laser rangefinder for fast industrial measurement applications with the measurement accuracy of a few centimeters in the measurement range from /spl sim/1 m to /spl sim/30 m to noncooperative targets was developed. The receiver channel consists of a fully differential transimpedance amplifier channel, a peak detector, an rms meter and a timing discriminator. In this particular application there is no time to measure the received signal strength beforehand and it is not predictable from previous measurements, so a leading edge timing discriminator with a constant threshold voltage was used. The amplitude of the received pulse is measured with a peak detector and the amplitude information is used to compensate for the resulting walk error. The measured bandwidth of the receiver channel is 250 MHz, the maximum transimpedance 40k/spl Omega/ and the input-referred noise /spl sim/7pA//spl radic/Hz (C/sub photodiode/=2 pF). The timing detection accuracy of the receiver is better than /spl plusmn/35 mm in a single-shot measurement in a dynamic range of 1:4000 and a temperature range of 0/spl deg/C to +50/spl deg/C.     

多通道射频接收机测量噪声系数的新方法

噪声系数是多通道射频接收机的一个重要参数。传统的噪声系数测量方法对大噪声系数测量存在不足,且测量时通道间会有噪声干扰。提出一种多通道切换优化测量噪声系数的方法:通过设计1个八选一的射频开关实现信道切换,并引入前置低噪声放大器的控制电路提供冷热噪声源,优化Y因子测量噪声系数的方法,实现对各通道的精确测量。由于接收机前端的相似性,该方法可推广应用到其他的射频接收机。     

Design and characterization of a 250-350-GHz fixed-tunedsuperconductor-insulator-superconductor receiver

A fixed-tuned superconductor-insulator-superconductor (SIS) receiver has been designed to operate in the 250-350-GHz frequency band. This receiver has a double-side-band noise temperature of between 35 and 45 K, or about 3hν/k_B, over its entire operating band. Extensive characterization of the receiver has been carried out using techniques developed for submillimeter waves. The input noise, side-band ratio, 1 dB compression point, optimum LO drive level, and vector near-field beam profile have all been measured experimentally. The measurement techniques and results are presented and discussed     

A Receiver in a Millimeter Wave Radiometer for Atmosphere Remote Sensing

A millimeter wave radiometer system with high resolution is described in this paper, which was used for remote sensing of integrated water vapor and integrated liquid water in the troposphere. A novel receiver technique was adopted in the radiometer system to deracinate an impact of the receiver gain shift on its precision and improve its performance. Measured results show that this radiometer system has enough stability in long time measurement and capability to measure atmospheric brightness temperature.     

双向网改造中回传系统设计需要注意的问题

为了参与市场竞争,必须对有线电视网络进行双向改造,而网络的双向、互动、高效主要体现在回传系统的设计和建设上,为此根据实践经验,提出双向网改中回传系统设计需要注意的几个问题,只有在这几个方面精心设计、严格把关,才能保证回传通道的性能和质量。     

245 GHz接收机芯片片外测试与实验

为了实现太赫兹气体频谱分析传感器,对245 GHz次谐波接收机芯片的片外测试展开研究。建立了245 GHz次谐波接收机片外测试系统以及基于245 GHz接收机芯片及发射机芯片的气体频谱分析传感器片外展示测试系统,对245 GHz次谐波接收机芯片转换增益和带宽进行测试。片外测试系统得到15 dB转换增益和15 GHz带宽;片外展示测试系统得到9 dB转换增益和16 GHz带宽。片外测试系统和片外展示测试系统结果基本吻合。在片外展示测试系统中加入气腔,即构成气体频谱分析传感器。与现有同类型传感器相比,本文的次谐波接收机具有高增益、高带宽、集成本地振荡信号、低功耗等优势,非常适用于消费电子领域小体积的智能气体频谱分析传感器。