解析24 GHz频段短距雷达设备电磁兼容欧洲标准

解读ETSI EN 302288-1中对测试电源的极端电压和环境的温、湿度要求。介绍短距离设备的频率范围、功率密度、杂散发射与带外发射等测量参数,以及电波暗室中辐射测量的通用测量方法和场地要求。     

解析25～1000MHz短距离设备电磁兼容欧洲标准

介绍短距离设备欧洲标准ETSI EN 300 220-1 V2.3.1的测试模型选取和测试条件;详尽分析频率误差、平均传导功率、有效辐射功率、扩频调制、瞬态功率、临近信道功率、调制带宽、杂散发射、频率稳定性和占空比等发射机参数,以及灵敏度、LBT阈值、临近信道选择性、阻塞性能、杂散抑制和接收机杂散等接收机参数;并对全电波暗室、半电波暗室和开阔场的试验场地、试验布置和测试方法进行分析说明。     

自由空间损耗补偿在1GHz以上辐射杂散发射测量的应用

详细介绍了无线通讯产品通过自由空间损耗补偿进行1 GHz以上辐射杂散测量的方法,以及在电波暗室中对自由空间损耗进行校准的方法。通过对自由空间损耗校准结果进行理论分析以及验证,阐明自由空间损耗补偿在1 GHz以上辐射杂散测量中的实际应用。     

利用带状线法和电波暗室法进行小型车载电子产品辐射发射测试的比较研究

根据CISPR25和GB/T18655标准的要求,该文分别利用带状线法和电波暗室法对小型车载电子产品的辐射发射进行测试。并针对两种方法的测试结果进行比较分析,验证在无电波暗室的情况下,利用带状线法来进行辐射骚扰场强摸底测试的可行性,为企业摸底提供了有利条件,具有很大的现实意义。     

多功能电波暗室应用技术

该文介绍了电磁兼容测试需要的多功能电波暗室,成为多功能电波暗室应具备的基本功能,对满足标准要求的多功能电波暗室所需具备的性能指标进行描述及相应的测试要求,如基本的NSA,Svswr,FU。对在多功能电波暗室中进行不同项目测试时所对应的场地布置进行了分析,最后对多功能电波暗室的优劣进行了总结。     

解析315～600kHz短距离设备电磁兼容欧洲标准

介绍了短距离设备欧洲标准ETSI EN 302 536-1 V1.1.1的测试模型选取方法,测试条件,以及电源和环境要求。同时,分析了辐射测试场地和测试布置。最后,详尽解读了315～600 kHz频段短距离设备的载波输出电平、调制带宽、杂散发射和占空比等发射机参数,以及接收机杂散等接收机参数。     

厦门市产品质量监督检验院EMC检测实验室

厦门质检院EMC实验室现拥有1个10米法电波暗室,2个3米法电波暗室,1个汽车零部件电波暗室以及正在筹建的2个车联网专用暗室(含整车测试能力),同时配备了国际一流的检测仪器设备、资深检测及整改人员,获得包括CNAS、SGS、ITS等国内外权威机构的认可和授权,具备IEC、CISPR、ISO、EN、SAE、JASO、GB等标准试验能力,可满足CCC、CE、C-TICK、FCC、PSE、E-Mark等全球范围认证与测试服务要求.     

30 MHz～1 GHz辐射发射试验场地确认测试实例剖析

场地衰减偏差是评估半电波暗室(SAC)是否满足30 MHz～1 GHz射频电磁场辐射发射测试要求的关键指标.针对某SAC场地衰减偏差的多次测量结果,从扫频测量参数、天线塔和电缆组件、测量天线的巴伦阻抗特性、溯源场地特性差异等方面进行剖析,讨论导致测量结果差异的主要因素.     

解析1～40GHz短距离设备电磁兼容欧洲标准

对短距离设备（SRD）欧洲标准ETSI EN300 440-1 V1.6.1进行解读,介绍了测试模型的选取、测试环境条件,同时较详尽地分析了发射机和接收机的参数要求,其中发射机参数主要包括有效全向辐射功率、工作带宽、杂散发射和占空比。接收机参数主要有临近信道选择性、阻塞性能和接收机杂散。最后,对传导和辐射测试场地和试验布置,以及SRD设备中常用的几种频谱访问机制进行了概括说明。     

半电波暗室的技术要求

EMC实验室的性能是否满足所提的技术要求和设计指标,要靠测试数据验证.简要说明了电波暗室的特点,详细介绍了半电波暗室的主要技术要求及一些暗室建设的注意事项,为提出实用的暗室建造技术要求、实验室的验收要求提供依据.     

手机杂散干扰控制方法

结合测试结果与产品设计,总结了排查问题的流程。分析了手机中出现杂散干扰的不同原因,比如由手机的发射机、功率切换、等效天线和电源芯片等引起的杂散发射,并分别提出了滤波、调整信号上升沿/下降沿时间、消除等效天线等整改措施。整改后,手机杂散测试合格。     

解析401～402MHz与405～406MHz短距离设备电磁兼容欧洲标准

介绍了短距离设备欧洲标准ETSI EN 302 537-1 V1.1.2的测试条件、电源要求和环境要求,分析了辐射测试场地和测试布置。最后,详尽解读了401～402 MHz与405～406 MHz频段超低功耗医学设备的频率误差、发射带宽、有效辐射功率、杂散发射、低电压条件下的频率稳定度、基于低功率低占空比条件的频谱访问等发射机参数要求,以及接收机杂散的要求。     

Phase noise measurement of a pulsed W-band IMPATT source

A test method is described that uses the Delay Line Bridge (DLB) discriminator as a phase modulation (PM)- or amplitude modulation (AM) detector. A brief discussion is given to explain the different measurement requirements for pulsed sources used in Doppler RADAR with stationary or slow moving transmitter platforms, and fast moving transmitter platforms. A practical solution is offered to the problem of inadequate isolation in present day W-band PIN switches. This measurement set-up, provides a direct measure of the level of spurious oscillations of the IMPATT source, the relative noise content in the turn-on and turn-off region of the RF pulse, and the phase ripple. It also illustrates the influence of reference source injection locking level on the measured characteristics.     

The Effects of Transponder Imperfections on the Error Probability Performance of a Satellite Communication System

The bit error rate (BER) performance analysis of a data communication system is generally based on the assumption that signal waveforms are ideal and hardware-induced distortion is absent. In a satellite communication system, such distortion arises in the satellite repeater, as well as in the transmitter and receiver portions. NASA, which is in the process of developing its Tracking and Data Relay Satellite System (TDRSS), is very much interested in understanding the impact of numerous hardware constraints, that have been identified, on BER performance. The present paper, which treats one segment of this broad problem area, examines the cumulative impact of nine forms of distortion induced by the repeater on BPSK and QPSK signals. These include frequency offset, filter amplitude and phase ripple, phase noise, spurious phase modulation (PM), AM/AM and AM/PM conversion, incidental AM, and spurious outputs. For the present analysis, the transmitter and receiver are assumed to operate in essentially ideal fashions and thermal noise is introduced at the receiver front end only. Computed results indicate that BPSK and QPSK performances are impacted in substantially different manners, with QPSK generally more sensitive to a given form of distortion. One noteworthy example is the combined impact of the phase noise and spurious PM parameters which affect BPSK only slightly, but lead to very rapid QPSK performance degradation as the parameter values increase. This and the other distortion effects are illustrated via computed parametric performance curves. Results also demonstrate the need to account for interactions among distortion parameters.     

Transmitter-to-Antenna Power Transfer Under Unmatched Conditions

One phase of the electromagnetic compatibility program is the determianation of the electromagnetic energy actually radiated into space by an antenna. Methods have long been established, or proposed, for measuring the power output of a transmitter, the antenna impedance, and the antenna-radiation pattern. However, very little definitive work has been published regarding the methods for computing the transmitter energy coupled to the antenna and radiated at harmonic and spurious frequencies. It is the purpose of this paper to reduce to a simple form the equations for determining the power absorbed by an antenna connected through a coaxial transmission line to a transmitter. Most discussions of transmission-line-power transfer assume the matched conditions so universally desired at the operating frequency. When harmonic and spurious frequencies are considered, both the transmitter and the antenna are likely to be poorly matched to the transmission line and to each other. This paper points out what measurements need to be made and gives the functional relations necessary to compute the power radiated under unmatched conditions. Since the actual power coupled to the antenna in a given instance may be critically dependent upon the exact length of transmission line, some means must be available to take this into account. The expressions derived give the maximum and minimum power that will be absorbed, and also give the probability that any specified intermediate power will be exceeded if a random choice of transmissionline length is used.     

广播电视发射系统的功率和杂散测量实例探讨

在所有民用发射机中,广播电视发射机的功率是最大的,同时也位于最高的发射点。由于广播电视发射系统存在着谐波,杂散和互调信号,因此会对其它的通信系统,如民航通信造成一定的干扰。本文从云南省无线电监测中心的应用角度出发,讨论了米波和分米波段大功率广播电视发射系统的功率和杂散测量问题。     

Sampled-grating DBR laser-based analog optical transmitters

Sampled-grating distributed Bragg grating (SGDBR) laser-based widely tunable optical transmitters are investigated for application in high-performance analog links. More than 45 nm tuning range, 40 dB sidemode suppression ratio, and peak relative intensity noise below -153 dB/Hz is measured. SGDBR lasers integrated with semiconductor optical amplifiers and electroabsorption modulators (EAMs) are characterized with spurious free dynamic range of 125-127 dB/spl middot/Hz/sup 4/5/ over the wavelength tuning range. It is also shown how the modulation response of the EAM is affected by the optical power to limit the performance of the analog transmitter.