CMOS反相器的电磁干扰频率效应

利用自主开发的2维半导体器件-电路联合仿真器,研究了CMOS反相器在1 MHz～20 GHz电磁干扰作用下的响应。仿真结果表明：低频电磁干扰通过控制CMOS反相器中MOS管的导通、截止影响CMOS反相器的正常工作;高频电磁干扰通过MOS管中的本征电容耦合到输出端,干扰CMOS反相器的工作状态;CMOS反相器对于电磁干扰的敏感度随着干扰频率上升而不断降低。     

CMOS反相器的电磁干扰频率效应

利用自主开发的2维半导体器件-电路联合仿真器,研究了CMOS反相器在1 MHz～20 GHz电磁干扰作用下的响应。仿真结果表明:低频电磁干扰通过控制CMOS反相器中MOS管的导通、截止影响CMOS反相器的正常工作;高频电磁干扰通过MOS管中的本征电容耦合到输出端,干扰CMOS反相器的工作状态;CMOS反相器对于电磁干扰的敏感度随着干扰频率上升而不断降低。     

Angular momentum of low frequency electromagnetic fields

The total angular momentum of propagating electromagnetic fields in the SVE-approximation is proportional to the power and the inverse frequency P/ω. This relation holds also in the low frequency range, but is decreasing due to the frequency dependent power of the antennas and becomes zero for ω → 0. Nevertheless, it is possible to generate strong angular momentum at low frequency by non-propagating electromagnetic fields (quasi-static fields).     

Parametric instability due to a low frequency whistler wave

A parametric instability is shown to exist in the presence of a low frequency $\text{(Ω}{}_{\mathrm{ci}}\text{～ ω}{}_0\text{? |Ω}{}_{\mathrm{ce}}\text{|)}$, finite amplitude, right hand circularly polarized wave. An expression for the growth rate and threshold is derived.     

Behavior of radon progeny in low frequency electromagnetic fields

Whether the electro-magnetic (EM) fields are carcinogenic or not still remains to be discussed from scientific point of view. Recently a possibility was pointed out that increased deposition of radon progeny in the EM-fields should enhance exposure dose to internal body. We investigated the behavior of charged ²²²Ru progeny and aerosols containing them by measuring the pattern and the magnitude of the deposition rate of decay products on both CR-39 track detectors and imaging plates under various conditions. We concluded that the attachment to wire cables should be increased mainly by electric component of low frequency EM-fields and possibly by electric field induced by strong changing magnetic ones.     

Experimental study of annoyance due to low frequency environmental noise

We have carried out a study of a particular environmental noise phenomenon which appears to be a cause of real and severe disturbance to certain people. The study has been based on field measurements and on laboratory studies and questioning involving two people who have suffered from this problem for some years. The disturbance is heard by them as a ‘throbbing’ sound and is particularly prevalent indoors, rather than out-of-doors.The study has indicated that the phenomenon arises with a broad band spectrum which lies close to the hearing threshold and which is unbalanced to the extent that the major stimulus occurs in the frequency range 20–100 Hz. It is suggested that the unbalanced spectrum may arise as a result of low frequency noise generated by distant industrial sources.     

重复频率电磁脉冲对氢闸流管栅极的触发干扰

针对重复频率电磁脉冲（EMP）干扰,以氢闸流管的栅极触发电路为研究对象,进行了氢闸流管悬置与共地两种不同的条件下氢闸流管第一栅极与第二栅极的电磁干扰研究。结果表明,两种条件下两个栅极均存在较强烈的电磁干扰,干扰主要来源于空间电磁辐射与共地耦合两个方面;针对重复频率EMP环境下氢闸流管触发的可靠性,分别进行了不同重复频率EMP数量与不同重复频率EMP时间间隔下氢闸流管的输出实验。结果表明,两种情况均对氢闸流管的触发产生影响,重复频率EMP数量增多与间隔减小均使氢闸流管误触发的可能性增大,对比理论分析与实验结果,认为该现象是由于重复频率EMP累积效应与重复频率EMP高频分量增强从而导致交互作用耦合增强所引起。     

重复频率电磁脉冲对氢闸流管栅极的触发干扰

针对重复频率电磁脉冲（EMP）干扰,以氢闸流管的栅极触发电路为研究对象,进行了氢闸流管悬置与共地两种不同的条件下氢闸流管第一栅极与第二栅极的电磁干扰研究。结果表明,两种条件下两个栅极均存在较强烈的电磁干扰,干扰主要来源于空间电磁辐射与共地耦合两个方面;针对重复频率EMP环境下氢闸流管触发的可靠性,分别进行了不同重复频率EMP数量与不同重复频率EMP时间间隔下氢闸流管的输出实验。结果表明,两种情况均对氢闸流管的触发产生影响,重复频率EMP数量增多与间隔减小均使氢闸流管误触发的可能性增大,对比理论分析与实验结果,认为该现象是由于重复频率EMP累积效应与重复频率EMP高频分量增强从而导致交互作用耦合增强所引起。     

电磁屏蔽用低频比小型化双频带频率选择表面

为满足敏感电子设备对频段密集相邻干扰信号的屏蔽需求,提出了一种低频比双频段带阻频率选择表面（FSS）结构。该结构由介质层和印刷在其两侧并谐振在不同频率的金属导带层构成。通过对两侧金属导带的互补型设计,削弱了两个谐振点间的耦合影响,使该FSS结构具有两个可以独立调节且紧密相邻的阻带,呈现出低频比特点。仿真结果表明,此结构可以实现低至1.16的谐振频率比。基于弯折结构的小型化设计使该FSS的单元尺寸仅为0.071λ,确保所提结构在TE和TM两种极化电磁波照射下,电磁屏蔽效能大于24 dB的入射角度稳定性高达60°。制作了实物并进行测试,实测结果与仿真结果吻合良好,验证了FSS结构设计的可靠性。     

On the low frequency electromagnetic response of strong coupling superconductors

In this paper we report about penetration depth measurements performed on strong coupling Pb–Bi alloys. The change of penetration depth with temperature is obtained from the frequency shift of a superconducting resonant cavity. The experimental results are compared with the low frequency electromagnetic response kernel calculated from the strong coupling theory and the scaled weak coupling theory respectively. A very good agreement between experiment and strong coupling theory is observed. The fit of the scaled weak coupling theory to the measured change of penetration depth yields values of the superconducting energy gap, which agree with the corresponding results of tunneling measurements.     

低信噪比下PSK信号的载频估计（英）

针对电子侦察中PSK信号的载频估计问题,提出一种低信噪比下载频估计新方法。该方法将PSK信号划分为等长度的交叠区间,提取各个区间内信号频谱的聚集性测度作为特征参数,然后将此特征参数导入网格密度聚类算法,以聚类结果作为载频估计特征类,最后将特征类对应的频谱叠加后提取峰值得出信号载频估计值。该方法避免了传统PSK信号载频估计的非线性运算,显著降低了PSK信号载频估计的信噪比门限,且无需先验知识,适合于电子侦察场合。仿真实验结果证实了该方法在低信噪比下PSK信号载频估计的有效性。     

A Gyrokinetic simulation model for low frequency electromagnetic fluctuations in magnetized plasmas

We present a new model for simulating the electromagnetic fluctuations with frequencies much lower than the ion cyclotron frequency in plasmas confined in general magnetic configurations.This novel model(termed as GK-E&B)employs nonlinear gyrokinetic equations formulated in terms of electromagnetic fields along with momentum balance equations for solving fields.It,thus,not only includes kinetic effects,such as wave-particle interaction and microscopic(ion Larmor radius scale)physics;but also is computationally more efficient than the conventional formulation described in terms of potentials.As a benchmark,we perform linear as well as nonlinear simulations of the kinetic Alfvén wave;demonstrating physics in agreement with the analytical theories.     

电子学系统强电磁脉冲干扰场路结合仿真

对设备机箱内部某串口电路受外界强电磁脉冲干扰所引起的信号完整性问题进行了研究,基于场路结合的仿真分析方法,从空间电磁耦合现象和电路信号干扰效应这两个方面对强电磁脉冲干扰进行了完整的系统分析,发现电磁干扰可导致内部电路出现逻辑电平翻转等扰乱效果,并提出了有效避免电磁干扰的措施。     

同轴电缆抗电磁干扰性能实验

利用自制实验装置，研究了同轴电缆的电容耦合频率特性、电容耦合屏蔽效果、电感耦合屏蔽效果．     

Experimental evaluation of the measurement errors of soil water content due to interference of two adjacent TDR probes

The objective of this experimental study was to determine the measurement errors caused by the interference effects when two TDR probes operate nearby in various distance apart for different soil types and soil water contents. The results will help to guide the design of an experimental apparatus which aims to study the coupled heat and moisture transfer in soils at high temperatures of higher than 40°C with the highest possible spatial resolution. The interference effect between two adjacent time domain reflectometry (TDR) probes has been evaluated and analyzed experimentally. It was observed that the distance between the probes, soil texture, and the water content of the testing soil is the key parameters which affect the interference and TDR probe capability of measurement. In this study, three types of soils were examined, namely FSJ#1 (silty clay), Matilda (loamy sand), and Ottawa sand C-190 (quartz sand). Three different volumetric water contents were evaluated for each soil. The interference effect was noticeable in all soil samples when the distances between the probes were 1 cm. For the samples with higher moisture content, the effect of interference on the TDRs’ electromagnetic waveform signals is more prominent. Interference was found in Matilda samples with degrees of saturations of 0.5 and higher even though the distances between the probes were greater than 1 cm; nevertheless, the determination of volumetric water content was not affected by the interference, because the interference only caused the two TDRs’ electromagnetic waveform signals to shift by the same length. No interference was observed in cases of FSJ#1 and Ottawa sand when the distances between the probes were greater than 1 cm. From the results, it was found that the sensitivity zone of our TDR equipment is a radius of about 10 mm surrounding the central needle of the TDR probe. In case of FSJ#1, when interference occurs, the measurement error of water content significantly increases from 9.3% to 15.5%, corresponding to the degree of saturation from 0.25 to 1.0.     

A criterion for predicting the annoyance due to higher level,low frequency noise

Annoyance due to low frequency noise is more qidespread than was at one time believed and case histories indicate that the annoyance is not predicted accurately by a dB(A) measurement. In this study the psychophysical magnitude estimation technique was used to determine if a predictor of low frequency noise annoyance, superior to the dB(A), could be found. Ten noise measures were considered and it was concluded tentatively that the dB(B) noise measure could be used to predict the annoyance due to levels of low frequency noise in the range 90–105 dB overall SPL.     

The interference sensitivity of bistable systems to subthreshold signals

A new approach to studying the influence of intense noise on the sensitivity of bistable systems detecting subthreshold signals is proposed. It is shown that the interference interaction between two identical bistable systems coherently excited by the same above-threshold noise may increase the sensitivity with respect to a subthresold signal by more than two orders of magnitude.     

On corrections due to higher-order electromagnetic transitions in nuclei

Beta and gamma transitions via virtual intermediate states may give small corrections to various physical effects. Beta-gamma and gamma-gamma angular correlations may receive contributions which are not symmetric around ninety degrees. Gamma rays following beta decay may have a small circular polarization. All these effects seem to be too small to be measurable at present or to interfere with parity experiments. Corrections to the spectrum shape factor of first-forbidden beta decays are discussed in view of the Bi²¹⁰ (RaE) decay.     

Information flow due to controlled interference in entangled systems

We point out that controlled quantum interference corresponds to measurement in an incomplete basis and implies a nonlocal transfer of classical information. A test of whether such a generalized measurement is permissible in quantum theory is presented. An erratum to this article is available at .