Cable Radiation Research Articles

Analysis of LTE-M Adjacent Channel Interference in Rail Transit.

Long Term Evolution-Metro (LTE-M), as a special communication system for train control, has strict requirements on adjacent channel interference (ACI). According to the 3rd Generation Partnership Project (3GPP) protocol of the European Telecommunications Standards Institute (ETSI) standards, this paper presents the required isolation degree for LTE-M systems to resist ACI. Aiming at the scenario of leaky cable transmission and antenna transmission adopted by the underground LTE-M system of the subway, the isolation degree required for LTE-M system deployment is deduced by combining the channel description with the principle of ACI. For the coexistence of a LTE-M system and an adjacent cellular system in a subway ground scenario, the Monte-Carlo (MC) method is used to simulate several conceivable scenarios of the LTE-M system and the adjacent frequency cellular system. In addition, the throughput loss of the LTE-M system is estimated by considering signal to interference plus noise ratio (SINR). Simulation results demonstrate that adjacent frequency user equipment (UE) has negligible small interference with the LTE-M underground system when using the leaky cable radiation pattern, whereas for the LTE-M ground system, the main interference comes from the adjacent frequency UE to the LTE-M base station (BS). Finally, interference avoidance solutions are presented, which can be utilized as a reference in the design and deployment of LTE-M systems in the rail transit environment.

Comparison between Measured Data-Carrying VDSL2 Cable Radiation and Radiation Limits for Wire-Line Telecommunication Networks

Comparison between Measured Data-Carrying VDSL2 Cable Radiation and Radiation Limits for Wire-Line Telecommunication Networks

The Simulation Analysis and Coupling Mechanism of harness and wire cable

Considering the complexity of the electromagnetic environment, a large number of electronic equipment and cable harnesses are concentrated. For different environments, this paper is prepared to consider the three problems of cable crosstalk, field-line coupling and cable radiation, which basically covers all cable electromagnetic interference problems. Considering the changes of cable length, cable height from the ground, cable distance, angle and grounding mode, this paper also takes these factors into account and explores the results by changing these parameters. According to this, the anti-interference measures between the cables of Electrical Multiple Unit can be obtained.

A Proposed Terminal-Ground EMI Filter for Reduction of Conducted Emissions Considering Cable Radiation and Safety

This article proposes an optimal design of a terminal-ground electromagnetic interference filter (TGEF) for reduction of common-mode (CM) conducted emissions (CEs) with considering cable radiations and safety. The TGEF is free from risks of magnetic saturation and heat problem. In experimental tests with a 3.3-kW air conditioner system, a prototype TGEF well reduced low-frequency CM CE noises, but increased disturbance power (DP) due to cable radiations. To investigate the principle of cable radiations, the impedance and parameters in the DP measurement setup are extracted by measurements using a vector network analyzer and validated with full-wave simulations. The effects of the TGEF on total CM DP currents at power cables are also experimentally demonstrated and modeled in simulations. Based on the analysis of DP measurement environments, a quantitative guideline for a TGEF design was proposed without increasing cable radiations while maintaining CE noise attenuation performances. The performances of the optimized TGEF are then validated by CE and DP measurements in the real product system. Moreover, safety of the optimized TGEF in a ground-fault condition was experimentally confirmed.

Insulation Failure Prediction Model of Power Cable in Fire

With input parameters being determined, simplified physical model and heat conduction equation were adopted to establish a power cable insulation failure prediction model in fire, and the validation test was carried out. The internal structure of the cable was simplified to a one-dimensional physical model with three layers, to derive the calculation method of internal structure parameters of cable physical model. Differential equation of heat conduction, which could reflect the internal temperature of cable, was constructed based on basic assumptions, to establish a cable insulation cable failure prediction model with mixed layer heat diffusion coefficient, environment temperature change and insulation cable failure temperature as input parameters. The method to determine model input parameters was also proposed. ZR-YJV and SDR-1 cable thermal radiation furnace were selected in the experiments to obtain insulation failure temperature and time, as well as environmental temperature change of the cable. The experimental results showed that the constructed model had relative small error in predicting cable insulation failure time.

Measurement of Deep Tissue Implanted Antenna Efficiency Using a Reverberation Chamber

We investigate the use of a reverberation chamber for the experimental measurement of deep implant antenna radiation efficiency. The technique was able to measure the extremely low efficiencies associated with deep implant antennas inside a muscle tissue-mimicking liquid phantom. Results were obtained for a range of insulated and un-insulated antennas with efficiencies as low as 0.06%. Analysis showed that while measurement errors were dominated by positioning variability, spurious feed cable radiation is still a significant factor that must be considered. Depending on the radiation characteristics of the antenna under test and the feed cable routing within the phantom, cable radiation could lead to errors of up to 4.5 dB.

Experimental evaluation and FDTD method for predicting electromagnetic fields in the near zone radiated by power converter systems

This paper presents the study of conducted electromagnetic interference (EMI) currents flowing through the power cables of a DC-DC converter system and its correlation with the near field radiated from these cables. The radiated emission measurement contains a common mode (CM) and a differential mode (DM), and accurate separation of the radiated emissions of these two modes is necessary. The finite-difference time-domain (FDTD) method is used to predict the electromagnetic radiation caused by CM currents and DM currents. An experimental bench has been designed to allow access to the measurement of EMI disturbances at various sensitive places. The CM and DM voltages resulting from the experimental measurement are implemented in the FDTD algorithm as voltage sources of disturbances, these disturbance voltages causing the generation of CM and DM currents flowing through the cable. Finally, single and bifilar wire models for modeling the near field using the FDTD method are presented and the simulation results of the near field caused by both of the modes are evaluated and compared with the experimental ones. The main objective is to investigate the significance of the contribution of each of the current modes on the radiated emissions from the cable using the FDTD method, thus characterizing the level of cable radiation versus a specific standard. This allows showing that the radiation is often caused by the CM current along the cable and the largest level is located in the switching noise zone located within the frequency range from 1 MHz to 10 MHz.

Study of Application in Network Intrusion Prevention

Network intrusion prevention application are studied, analyzed vibration optical fiber, cable radiation, infrared radiation, tension fences, high-voltage pulse and other key technologies, proposed safe city, government investment, government rent, lease operator platform, operating mode, and applications in key areas of finance, police, parks and other surveillance industry.

MAKING SENSE OF RADIATION: A GUIDE TO RADIATION AND ITS HEALTH EFFECTS

Long absence of national research body and national policy for research in Sudan are responsible for inefficient research system. This shaped and determined the main features of health research. Most of health research is done for academic purposes. It is fragmented and done in isolation within each research institution. There are no means of communication or coordination between numerous research and academic institutions involved in health research. Publication and dissemination of research findings is not well observed. Any national authority does not govern health research and even policies or regulations do not exit. Despite the early mentioned research activities, there is no obvious impact of research in health development in the country. A meticulous literature review and extensive consultations were made to build a comprehensive approach to conduct this work. This study was performed in Khartoum state and it focuses in mobile phone mast, Pylon’s cable, Electrosensitivity and EM radiation in 2008. The study investigated Public discussion about radiation is a frustrating mixture of truths, half-truths and conjectures. As a result, some people are being made to worry unnecessarily about electric fields from pylons and radiation from mobile phones and computers. The results of this paper were an increased incidence of leukaemia among children living next to pylons and other more recent studies have found a similar association. Psychologists have long known that worry and anxiety can lead to strong physical changes in the body and that seems to be what is happening to ‘electrosensitives’.

Miniaturized printed monopole antenna with applying the modified conductor-backed plane and three embedded strips based on CPW for multi-band telecommunication devices

In this article, a new construction of a small planar dual-band fed printed monopole antenna based on coplanar waveguide is suggested. Impedance matching for dual-band operations is obtained by embedding three vertical strips with different sizes in the U-shaped conductor-backed plane. The main problem of the designed antenna is the measuring of the specifications with the Agilent 8722ES Vector Network Analyzer, when the coaxial cable is connected to the antenna. Hence, in this paper a new method for decoupling the cable from the antenna is presented. This method is based on using the ferrite bead. The ferrite bead reduces the cable radiation, so that its position plays the important part in the antenna radiation characteristics. The fabricated antenna includes the benefits of the miniaturized size and dual-band operating specifications, so that the mentioned properties have been achieved without modifying the coplanar-waveguide-ground surface or radiator patch. The antenna has the small size of 15 × 15 × 0.8 mm3and bandwidths with S11 < −10 dB about 2.2 GHz (5.05–7.25 GHz) for WLAN-band or IEEE 802.11a-band and 5.2GHz (7.6–12.8 GHz) for X-band, which correspond to 36 and 51% practical bandwidths, respectively. The antenna measured peak gains are about 1.8 dBi at WLAN-band and 4.3 dBi at X-band.

Measured patterns of a resistive V‐dipole fed with a double‐Y balun

AbstractThe performance of a double‐Y balun feeding a resistive V‐dipole is evaluated via antenna‐pattern measurements. An optical link is constructed for containing the feedline radiation to a laser receiver unit and the antenna under test (AUT), hence avoiding the uncertainty caused by cable radiation in a conventional antenna pattern‐measurement setup. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 380–383, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21356

Coupling of Apertures in Enclosures to External Cabling Structures

In addition to the direct radiation from enclosure apertures, an indirect contribution also exists due to the coupling to external cables. Based on an inductive coupling model, a relation for the external coupling voltage is derived and combined with a resonant dipole-antenna model for worst case estimations of the radiation level. An expression for the direct-to-indirect radiation-amplitude ratio is deduced. The model is well confirmed by a numerical example for a rectangular box with a slit. The results clearly indicate that in the low-to-intermediate frequency range the indirect cable radiation exceeds by far the direct radiation from the aperture.

Radiation due to an infinitely imposed current line source near a dielectric elliptic waveguide: A dyadic Green's function approach

In this paper, the dyadic Green's function technique has been employed to characterize electromagnetic radiation of an imposed current line source in the presence of an isotropic dielectric elliptic cylinder. The current density along the infinitely long wire has a constant amplitude but a varying phase. The elliptic cylinder is considered to be infinite in length. In order to analyze the problem, the dyadic Green's functions are expressed in terms of elliptic vector wave functions and the general equations needed to solve for the reflection and transmission coefficients are derived from the boundary conditions. These derived equations are transformed into, and solved using, a linear equation system. Numerically, the radiation patterns of the infinitely long wire are computed, plotted, and shown for various cases where the position and distance of the line source are varied. Both lossy and lossless dielectric media for the elliptic cylinder are considered. The results are believed to be very useful to many practical problems, and especially to characterize cable radiation or transmission line power leakage in tunnels.

Analysis of ferrite beads for RF isolation onstraight wire conductors

Ferrite beads used for the supression of electromagnetic interference (EMI) were analysed using the finite difference time domain (FDTD) method. The presence of the bead results in reflected current, cable radiation and resonant characteristics which significantly affect the ability to suppress currents uniformly over a wide frequency range. A typical low conductivity ferrite bead (σ = 1 µS/m, ɛr = 1, μr = 100), with length L = 21 mm and outer diameter D = 11 mm is shown to be a poor isolator at 1.03, 1.71, 2.37 and 2.93 GHz due to this resonance phenomenon. The effective suppression of EMI depends on the properties and dimensions of the ferrite bead in addition to the frequency of operation.

Simulating measurements for a cable radiation study

Accurate numerical simulations are needed for analyzing and developing better electrical interconnects and electromagnetic compatibility (EMC) measurement systems. Numerical simulations enable one to predict the field behavior and compute the voltages, currents, impedances and other parameters of interest for a given structure such as cable shielding. A numerical simulation is used to analyze measured data from a cable radiation study. The finite difference time domain (FDTD) and the method of moments based Numerical Electromagnetics Code (NEC) are used to compute the total radiated power from the cable, and the results are shown to be in agreement with measured data. A numerical study is carried out to demonstrate the usefulness of the method at aiding the design of a measurement system without much additional experimental work.