基站共享站址条件下电磁辐射的计算研究

介绍了国内基站电磁辐射防护的规定,描述了单辐射源和多辐射源电磁辐射强度的理论计算方法,并以此为基础建立多种制式的基站共享站址的基本模型,然后对该模型进行电磁辐射的计算,并对结果进行了研究分析。     

电磁辐射和电子产品可靠性探究

介绍了电磁辐射的检测方法并分析了电磁辐射污染对电子产可靠性的影响。     

5G手机电磁辐射检测认证与探讨

以5G手机的电磁辐射为出发点,介绍了5G手机电磁辐射检测认证的限值要求、评估方法、测量系统,开展了5G与4G的比对实验,并对相关数据进行比较分析,最后阐述了目前5G手机电磁辐射认证中遇到的问题。     

用频装备带内双频窄谱电磁辐射阻塞干扰效应预测模型

针对传统单频连续波电磁辐射敏感度试验方法无法满足用频装备多辐射源共同作用下复杂电磁环境适应性评估的技术需求，本着有限目标的原则，对用频装备在带内双频窄谱电磁辐射作用下的阻塞干扰效应预测问题进行了研究.从用频装备单频和调幅连续波敏感度试验数据出发，基于用频装备带内电磁能量耦合及共性干扰、损伤作用机理分析，研究了有效值敏感和峰值敏感两类用频装备带内双频窄谱电磁辐射阻塞干扰效应预测模型并提出了预测方法，给出了受试用频装备适用预测模型的判定方法，并以某型超短波通信电台为受试对象，试验验证了模型及方法的有效性.研究结果表明:本文提出的模型和方法可有效应用于用频装备在带内双频电磁辐射作用下的阻塞干扰效应预测和评估.     

贺州市城区环境电磁辐射监测与分析

随着电子通信设备、设施的迅猛发展,以及人们对健康和环境问题越来越重视,电磁辐射逐渐成为备受人们关注的话题.本文以广西贺州市为例,通过射频辐射监测比对分析,得出贺州城区电磁辐射环境状况良好的结论,并提出了电磁辐射环境监管的建议.     

典型4G移动通信基站电磁辐射环境监测与影响评价

本文开展了对4G基站电磁辐射的研究。在温州试验网选择典型的4G基站,并对其进行电磁辐射环境实测,以说明4G基站对周围环境的影响。测量仪器和方法都选择了业界通用的方法。研究结果表明,一般情况下,4G基站对周边环境电磁辐射水平的影响较小,符合国家相关标准的要求。     

大型短波广播发射台电磁辐射环境非等距网格测量法

大型短波广播台源项众多,影响区域内的电磁辐射水平分布情况复杂,目前常用的电磁辐射源环境检测方法均无法全面准确地测量出其对周边电磁辐射环境的影响情况,为此提出一种基于最大相对误差控制算法的非等距网格测量法.该方法根据大型短波广播发射台周边电磁场变化规律理论分析结果,控制网格拟合值与网格内理论计算准确值的最大相对误差,考虑现场环境对电磁场变化影响和检测点位布设可行性确定检测网格尺寸,在电磁场强度变化很大的区域采取小网格提高检测取样的抽样率,在电磁场强度变化不大的区域采取大网格降低检测取样的抽样率,不仅保证了测量结果的精准度,同时也合理地降低了实际工作量.     

移动通信基站电磁辐射测量示范系统的设计

为了进行移动通信基站的电磁辐射研究,需要建立基站电磁辐射测量示范系统。设计了电磁辐射示范系统的架构,通过对各模块功能的分析,制定了数据传输和数据采集的工作流程。根据系统的功能,提出了监测点和数据处理中心的技术要求。测量系统除了考虑检测方法研究外,还设计了数据公众分享接口,以便于公众知情电磁辐射状况。     

电磁辐射的环境管理

介绍了电磁辐射污染源的种类和特点,电磁辐射污染对人体健康的危害以及设备或系统的干扰和影响,简述了电磁辐射环境管理法规、标准及管理现状,特别介绍了江苏省移动通信基站建设项目的环境管理实践,探讨了电磁辐射环境管理控制对策。     

基于矢量有限元法的热沉结构电磁辐射研究

 高频、高功率芯片工作时会产生大量的热,热沉可以有效地帮助芯片散热.然而在高频环境下,热沉往往成为主要的电磁辐射源,降低了整个系统的电磁兼容能力,所以有必要对热沉的电磁辐射特性进行研究.本文采用矢量有限元法,从不同的接地方式、散热鳍片数目及厚度变化、鳍片高度变化几个方面分析了热沉的电磁辐射特性,提出了影响谐振频率的关键因素,并从电磁兼容角度提出了热沉设计的注意事项.数值仿真表明,合理的选择接地方式可以有效地提高谐振频率,降低电磁能量辐射;散热鳍片的数目和厚度变化对于谐振频率和电磁辐射没有明显的影响,然而鳍片的高度对于电磁辐射能量影响显著.     

Minishields of electromagnetic radiation

Resonant minishields based on a pair of closely spaced capacitive gratings are proposed. The resonance frequency of such screens is calculated and measured. The possibility of realization of minishields at frequencies of 1.8 and 2.5 GHz is shown.     

Liquid crystal electromagnetic radiation monitor

Liquid Crystals having color play centered at different temperatures are arranged on metal coated and nonmetal coated dielectric substrates and used to monitor electromagnetic radiation. While both substrates respond to changes in ambient temperature conditions, the metallized substrate will also have temperature changes due to absorbed radiation. The temperature-dependent light scattering properties of the liquid crystals are used as both the temperature measuring mechanism and the indicating mechanism, with the difference between the temperature indications of the two substrates being a measure of the radiation. An experimental model that measures radiation of 1 to 15 mW/cm2 at 2.45 GHz is described.     

Rotational symmetries of electromagnetic radiation fields

Maxwell's equations and their solutions have been examined from the point of view of the full rotation group. Two mapping theorems have been derived which give the rotational symmetries of the radiated electric and magnetic and Poynting's vector field as a function of the symmetries of the electric current density which acts as the radiating source.     

Non-ionizing electromagnetic radiation monitoring in Greece

The design, development, and operation of a network for the monitoring of the non-ionizing electromagnetic radiation in Greece is presented in this paper. Two independent sub-networks, called “Hermes” and “pedion24” have been operating since November 2002 in many areas, and more than 4,000,000 electric field strength measurements have been conducted to date. The measurement results indicate that the non-ionizing electromagnetic radiation levels are several times below the European Commission Recommendation 1999/519/EC and the Hellenic Republic Law no. 3431 reference levels.     

On the electromagnetic radiation of printed-circuit-board interconnections

Large ground and supply layers on interconnected boards represent a radiating antenna structure which may be efficiently excited at its resonances by small high-frequency potential differences. Such potential differences between the boards mainly originate from the inevitable inductive impedance of the signal-current return path in the connector, usually provided by ground pins. The presented modeling approach is based on an antenna transfer function for the global interconnecting structure and a partial-inductance equivalent circuit for the connector. As shown by the example of a motherboard-daughterboard structure, the model enables a systematic study of the radiation mechanism, depending on signal/ground-pin configuration, as well as geometrical and electrical parameters. In conjunction with SPICE simulations of the connector equivalent circuit, the signal driver and receiver dynamic characteristic can also be properly included. Validation is provided by full-wave simulation and measurement results.     

ON ENERGY CONSERVATION IN ELECTROMAGNETIC RADIATION PROCESS

The energy conservation in the radiation process by electron beam in a wave guidewith arbitrary cross section is proved.Some mistakes in Ref.[1]by myself are corrected.And theresults are extended to the waveguide system with one shorted end.This result explains that theenergy conservation is intrinsic attributes of the Maxwell's equation set.     

电磁感应式无线充电发热与电磁辐射仿真研究

目前大多数对于无线充电电磁环境安全的研究都局限在电动汽车磁共振式无线充电,然而电磁感应式无线充电装置更接近人体,使用时间更长,本文针对电磁感应式无线充电导体异物易感应出涡流引起发热以及人体电磁辐射问题进行了仿真研究. 无线充电系统结构参考Qi标准,首先利用参数电路对负载电阻、线圈间距及偏移距离对传输效率和输出功率的影响进行仿真;随后使用确定的参数仿真研究不同材质的导体异物在30 min内的温升. 仿真结果表明:当导体异物正对线圈时温升明显,金银等材料的温度均可达100 °C以上;当导体异物不正对线圈时,温升在可接受范围内. 最后使用CST仿真得到电磁场强度、人体温度以及CEM43 °C热剂量值,以此来体现电磁感应式无线充电对人体电磁辐射的非热效应及热效应,电场最大值0.642 7 V/m,磁场最大值2.694 0 A/m,人体大脑温度最高37.3 °C,CEM43 °C热剂量值0.009 5,结果基本在正常参考值范围内. 本文研究有利于电磁感应式无线充电装置的推广应用.     

Modulation of mammalian immunity by electromagnetic radiation

There have been reports that electromagnetic radiation (EMR) alters the function of the immune system; however, these reports are often contradictory. This review reexamines the literature and attempts to evaluate the data on potential mechanisms of interaction of EMR on mammalian immune function. This report concludes that there is no convincing evidence that EMR effects on the human immune system are a health hazard. It was suggested by some authors that long-term EMR exposure may impair immune surveillance, and hypothetically thus facilitate tumor growth. Additional research is needed to prove or disprove this hypothesis. Available data indicate that EMR exposure does not affect the ability of cells of the immune system to respond to a subsequent challenge. However, the time-course and magnitude of the response may be affected by exposure following stimulation. Research to date provided evidence that at least at some frequencies and/or amplitude and pulse modulations, the site of primary interaction of EMR is at the cell membrane. However, it was shown that one specific response, the increase in B complement-receptor positive lymphocytes (Cr+) in the mouse is under genetic control by a single gene localized on chromosome 5. It is suggested that cells of the immune system are a convenient model for further studies on mechanisms of EMR interaction with living systems. Future research should be directed at exploring beneficial medical applications of EMR modulation of immune responses.     

一种电磁脉冲辐射系统设计

提出一种电磁脉冲辐射系统设计方案,此系统由Marx发生器、短路-锐化组合开关型脉冲形成线和带低频补偿的高功率超宽带横向电磁波(TEM)喇叭天线组成。Marx发生器产生的单极脉冲经过短路-锐化组合开关型脉冲形成线锐化成双极脉冲,然后馈入天线进行辐射。仿真结果表明,在充电电压为10 kV时,电磁脉冲源可产生脉冲宽度1.41 ns、峰值功率7.69 MW的双极脉冲,此双极脉冲频谱主要分布在0~1.6 GHz频率范围内;高功率超宽带TEM喇叭天线带宽为0.625~2.9 GHz(相对带宽为129%),功率容量可达10 MW,能有效地将电磁脉冲源产生的双极脉冲辐射出去。