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EMI - Science topic

Explore the latest questions and answers in EMI, and find EMI experts.
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Is that a strong research to investigate lecturers' perceptions to English Medium Instruction (EMI) in China?
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Junwei Liao Investigating lecturers' perceptions of English Medium Instruction (EMI) may be a fruitful research subject since it can give insight into the experiences and perspectives of the instructors in charge of providing EMI in higher education settings. In particular, as the use of English as a medium of instruction has increased in China in recent years, researching lecturers' opinions of EMI can aid in understanding the obstacles and possibilities connected with this transition in language use.
The study might be valuable for Chinese educators and administrators involved in the implementation of EMI in higher education. It can, for example, aid in identifying areas where lecturers are confident and well-prepared, as well as places where they may want more assistance.
It can also reveal how lecturers are adjusting to the use of English as a medium of instruction, as well as the impact this change is having on their teaching and students' learning.
Furthermore, the research can benefit institutions by giving feedback on the EMI policy, the amount of teacher training, and support. It can also benefit policymakers because the study can assist to guide the development of EMI policies and strategies in higher education.
Overall, researching lecturers' impressions of EMI in China may be a significant study topic since it can give insight into the experiences and perspectives of the instructors who are in charge of teaching EMI and assist to understand the difficulties and opportunities.
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I worked at field with EM38-MK2 instrument. Results of raw readings vizualised at picture below. I don't understand why readings for 0.5 m base are predominantly negative. Calibration? But I calibrate instrument before survey at 1.5 m. Conditions around were uniform.
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Q can be easily converted into apparent conductivity by a simple multiplication if the the instrument is working at very low induction numbers B which is defined by the ratio between coil separation (s) and the skin depth, i.e., it is valid when s is very small in relation to the skin depth which is inversily proportional to the conductivity. Of course this formula applies only to homogeneous media or layered earth. when the subsurface has heterogenities it fails, e.g., can lead to negative conductivities...
Unfortunately I did not work with EM38-MK2...
If you want to take a look at my PhD thesis maybe it could help you... it is avaialable here in research gate.
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Respected sir
Kindly provide the solution to the above question.
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Respected, Researcher,
Kindly suggest the important 2D materials which show the highest EMI property.
I am looking forward to the design and fabrication of a radio frequency (RF) Antenna.
As I found, the Ti3CTx shows 98dB EMI shielding.
What are the other materials that indicate more than this? If so, kindly mention it in the comments.
Herewith I attached one related paper for the same.
Thank you for your support and suggestions.
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For EMI shielding, it is important to not just look at the absolute value, but to also consider the thickness of the material. For EMI shielding materials, the higher the conductivity, the better the EMI shielding ends up being (in most cases!) Generally, what we've observed for MXenes (Mn+1XnTx) are that their EMI shielding efficiency also depends on the conductivity of the MXene. To date, the highest conductivity reported for a MXene is Ti3C2Tx which has values above 20,000 S/cm ( )
Considering this, Ti3C2Tx appears to be the best MXene for EMI shielding. However, there was a recent article published in Science ( ) that shows that annealed Ti3CNTx has a higher EMI shielding value at the same thickness. This means that there is some fundamentally different mechanism that is occurring with Ti3CNTx over Ti3C2Tx.
Now, to further add some information, all MXenes will have EMI shielding capabilities, but at different amounts. In this article, 15+ MXenes were tested using a uniform methodology ( ). What we found is that generally MXenes will follow the correlation between conductivity and EMI shielding efficacy. However, some MXenes show significantly higher EMI shielding efficiency than is expected based on their conductivity, meaning that there is some other physics happening that we currently cannot explain.
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Electromagnetic interference (EMI) is a phenomenon that may occur when an electronic device is exposed to an electromagnetic (EM) field. In general, in the today world of technology, electromagnetic pollution is very dangerous to human health and living things and can also adversely affect the performance of electromagnetic devices. This can show the importance of EMI shielding.
Conductive polymer composites show desirable characteristics in the electromagnetic absorption. I want to know, where are the exact application of EMI shielding materials?
And by "exact", I mean, in which devices? Which industries? How much shielding effectiveness (dB) is needed in each application, etc.
I will be thankful for any help.
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in addition to what has been mentioned already (Rf loads) : anechoic chambers;
filters are often of reflective type (i.e. reflect the incoming power outside the passband); and of course stealth technology..
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Dear colleagues,
recently there was a question here on RG about a mysterious high energy shoulder of a gamma peak.The real reason for that is unknown up to now.
One of my ideas is EMI interference with cell phone radiation.
It is well known, that cell phone (handy) radiation affects/irritates sensitive electronic equipment.
A HPGe detector is such a sensitive device.
Does anybody of you have performed tests about that issue; are there any experiences?
Any contributions are welcome...
Thanks in advance and best regards
G.M.
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does the shoulder appear in the total energy peak in the HPGe gamma spectrum of certain samples, there are two probabilities, if the problem in the HPGE detector, adjust it if not it is problem due to the high activity of the sample therefore it is necessary to remove the sample at the level of the detector to eliminate the peak sum phonomene
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I am looking for a survey questionnaire to collect quantitative data regarding students' perception on English medium instructions (EMI).
Could anyone suggest any reference material that can be helpful?
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Conductive, EMI shielding
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Dear Shoaib Aasim, aniline polymerizes via oxidative polymerization, using strong oxidants such as APS and the acids you mentionned. Please check the following document. My Regards
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Hello!
Were doing research on a material to test its performance and applicability for EMI applications, and we are new to this topic. We have determined the S value for our material from a vector network analyzer machine:
1. How can we calculate Permittivity and permeability from S parameters??
2. Can someone help us with information/ materials that we can use to help us understand and learn this subject.
3. Can someone describe the experimental procedure needed and give tips to calculate permittivity and permeability?
I am so grateful for your input and valuable help!
Thanks,
Ibrahim
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I give two references that will help you.
You can look at Rohde & Schwarz application note RAC-0607-0019_1_5E.pdf available from their website. You can also check Keysight Product Brochure 5991-2171.pdf that lists additional literature.
Happy reading :)
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I am scanning a PCB board for diagnosis EMI issue using hand held magnetic probe. What should be the orientation of the probe? Flat/parallel to pcb surface or perpendicular to it? Another question is how to measure Hx Hy and Hz separately using near field probe?
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To see some voltage in the port of the probe (in the spectrum analyzer), time-varying magnetic fields must penetrate the loop surface of the probe (i.e. the time derivative of the magnetic flux through the loop surface must be non-zero); so the best orientation of the magnetic probe on a PCB track is as shown in the picture attached.
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Most of the researchers have taken the Slygard 184 PDMS polymer for EMI shielding applications. So far I did not find any comparison that why this PDMS is preferable over the other PDMS types.
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Dear Mr. Ali,
there are many good shielding polymer concepts.
So it is not the best way to use Slygard 184 PDMS.
A good way is to use a polymer with very good intrinsic
particles ( MWNT or CNT or ... ).
Yours Sincerely
F. Gräbner
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What software do you recommend for a study that measures Ecological Momentary Assessment (EMA) data as well as seeks to test the impact of different Ecological Momentary Interventions (EMIs)? Ideally on low budget. Thanks in advance!
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Another update, Stefanie Mayer
We have rebranded to ExpiWell (www.expiwell.com) which has more than 2,100 researchers on the platform. You can easily implement EMA/EMIs on ExpiWell as we have key features that are helpful:
1. Ensuring time zone matching for participants (e.g., 8am is 8am regardless of timezone)
2. Enabling personalization of timings for participants (for lessons/activities/assessments)
3. Participant log to track response rates and message low response rate participants
4. Participants can view charts of their (formative) assessments (if enabled)
5. You can capture multimedia and location data
6. GDPR enabled
7. Payments can be made through the ExpiWell system
We are also partnering with several key organizations and institutions on EMAs/EMIs too and building out more features.
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Rekindling the old EGAP/ESAP debate of the EAP in the English-medium instruction (EMI) contexts.
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The possibility of applying Global Englishes in the EMI contexts.
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Although globalized English is a recognized phenomenon in the researchers' circle, it is yet to make its vivid presence in the language classroom neither in the outer or expanding circles. Perhaps you may wish to address the research debate among researchers concerning the role of English as an international lingua franca in international universities. I highly recommend Jenkin's outstanding contributions (2002,2005,2006,2014) in the field as well as the work of Canagarajah; Kachru; Graddol; and Seidlhofer; among others.
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ELECTROMAGNETIC INTERFERENCE SHIELDING WITH TEXTILES-DIFFERENT EMI SHIELDING CONDUCTIVE FILLERS OF METALLIC PARTICLES ON TEXTILE STRUCTURES
This is my current research
I s implement any novelty Ideas
Given to me
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Good afternoon, colleague!
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I am currently looking to administer an online questionnaire with staff and students working on EMI courses/programmes in SouthEast Asia and wondered if anyone could recommend any contacts. Ideally, I would like to reach out to both content faculty and those working on language/academic support (EAP) programmes. I’m also planning to do more in-depth analysis with several proposed university visits in 2019. I'm in the early stages of planning this project.
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Dear Nicola,
I am the head of Foreign Languages Department, South Ural State University, Russian Federation. I am deeply interested in the topic of EMI implementation and EMI teacher training. I would be happy to collaborate with you on the topic of EMI implementation and extend your research to the Russian Federation as much has been in Russia in the field of EMI implementation though it is not still visible on the global map of internationalization.
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Firstly, thank you for being interested in my question and opening this.
I'm having a hard time calculating input impedance by transmission line theory.
I'm a student studying microwave absorbers. In this field, it is necessary to calculate input impedance to finally obtain reflection loss.
I've uploaded a file showing the equation of transmission line theory.
In the equation, I wonder how I can treat 'j' in tanh when I calculate it in excel program.
I've tried solving the tanh part in many ways like this, but I couldn't
TANH((COMPLEX(0,1))*(2*3.14*((10)^(-2))*(2/3)*((M2*N2)^(1/2))))
TANH((COMPLEX((2*3.14*((10)^(-2))*(2/3)*((N2*O2)^(1/2))),1)))
IMPRODUCT("0+1i", "(2*3.14*((10)^(-2))*(2/3)*((M2*N2)^(1/2)))+0i")
I have no idea how I should threat 'j' in tanh
I'd appreciate it if you'd help me to solve this question.
Best regards.
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Why don't you try the same using FORTRAN/C/C++/MATLAB etc numerical software. Excel is good for office work, not for research.
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Working on PhD thesis and want to situate EMI within a recognised field of research. I feel the topic falls between a gap between English language learning and higher education when I aim to relate my arguments to the literature. While EMI is often used as a language learning tool, it is not essentially for the purposes of learning English but rather a way of delivering content in a lingua franca.
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I would suspect, as I think you do, that you will find affective strategies for both content and language. Perhaps then, your task could be to include the relevant literature from both fields with a view to 'closing the gap' by synthesising them for an 'emerging' field of EMI research. That doesn't, I'm afraid, lighten you workload, but ...
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In contrast with the traditional winding materials, I find it easier to introduce larger parasitic parameters during the manufacturing process of the full integrated EMI filter or LCL filter with FMLFs, it has significant negative impacts on the high-frequecny performance of the filter, are there any appropriate solutions to mitigate this defect? Besides, what's the principles to choose the size(concluding the CSA and length) of the flexible strip-foil , Maybe, it related to the power loss, while how to predict its high-frequecny loss(such as harmonic loss).
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Tony Maine Thank you very much for your suggestion. The advantage of using FMLF is that filtering inductance and capacitance can be integrated into the same unit. Therefore, the winding of L and N wires on the core is closely connected, just separated by a dielectric layer. It seems difficult to alleviate parasitic issue. Especially for CM inductor, the winding distance between L and N wires should not be too large, otherwise, the CM coefficient will be decreased. In addition, the volume and weight of inductor should be considered comprehensively.
Now, I am trying to balance the requirements of inductance and capacitance based on meeting the requirements, find out the optimum structure and size of magnetic core as well as the size and layer-number of FMLFs, minimizing the number of winding turns, Thx for your answer again.
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Dear researchers and friends, please tell me the formula for calculating Reflection loss in EMI SE? I used 20 log [S11], is it correct?
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Thanks Rafia Raees.
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Hi,
I'm attempting to simulate conducted EMI using SPICE solvers in time domain and performing FFT afterwards for the frequency spectrum. But standards limits (CISPR/IEC) specify those limits in QP and AV and not in Peak values. Is it possible to convert/obtain the corresponding QP or AV spectrum by data post-processing ?
Thanks
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You need to replace the lowpass filter which follows your detector with an integrator, with the correct attack, decay and integration times.
Post processing would imply doing a convolution with the characteristics of such an integrator, which would be messy.
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It is confusing how pulsed signals are very different from switching EMI.
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Dear Sassia,
In my opinion and although they are related, pulsed signals cannot be directly compared to switching EMI.
It can be said that Switching EMI is a product of pulsed signals and it is caused by the fast rising/falling switching edges of pulsed (switched) signals.
The reason is that fast switching edges cause high frequency ringing (oscillations) due to the parasitic inductance and capacitance in a circuit. That high frequency ringing couples to the various wires/tracks of the circuit and is emitted, either as radiated emissions or conducted emissions.
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I would like to ask whether you think cultural competency inventories (surveys, questionnaires...) should be offered in each person's mother tongue(s) for true results or do you think doing them through English (as second language) is sufficient?
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It can be done both ways. At times English is self sufficient or at times mother tongue will contribute to more details. It actually depends on the personnel to whom you have floated the questionnaire and the place he is serving in the hierarchy of the organization.
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What is the measuring scheme/protocol for conducted EMI in DC/AC single phase inverter in both DC and AC side using LISN, and what are the differences in design between DC LISN and AC LISN ?
I'll be glad If anyone could provide /suggest good references (articles, books) regarding LISN design.
Thanks
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Prasanna Waichal, thanks for your answers !
I'll be glad to share the results.
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I need to have sufficient references as my evidences that EMI is still affecting the skills being developed in a foreign language classroom in which English is not the mother tongue. Thank you in advance for those who can help me up.
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If anyone works in EMI/EMC then please tell me about recent trends in investigation of EMI/EMC
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Dear gajanan,
Hope you are doing well. you can use IEEE Xpolar Digital Library to research about the recent publications in EMI/EMC. i think the attached link can help you.
Regards.
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I am working on EMI SE .I got S parameters values by using VNA.
S22 values are from 0.056 dB to -2.375 dB
S12 values are from -90.368 dB to -42.825 dB
As A = 1-(|S12|*|S12|) -(|S22|*|S22|)
as values are to be substract from 1 so, all the values are negative. and to find SE we need to take log , and log of negative number is not possible.
can anyone plz suggest how to solve this issue.
Is there any problem in S12 values ???
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Thomas
The data is from an HP vector network analyser - it is the standard format and I recognise the header - I work with these all the time. The data looks like it might be for something using x-band waveguide - it transmits above about 7 GHz, and is cut-off below.
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This is the first, tentative move into EMI for the University of Reunion Island.
The current teacher-training program (2 x 20 hours contact) covers:
An overview of EMI;
Academic and discipline-specific language;
Communication techniques to aid learning;
Teaching in an International Context.
Any resources or guidelines would be very much appreciated.
Stephan HOUGHTON.
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English Medium Instruction or English as a Medium of Intruction (basically teaching through English)
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Does strength of material affect shielding effectiveness of a material?
Does decreased tensile strength of composite material when compared to the neat matrix affect its EMI effectiveness?
Thanking you all in anticipation of knowledge sharing.
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Dear Mr. Kingsley Ajekwene,
no, the EMI SE effect of a bulk material is only a effect of the electromagnetic
intrinsic values.
Onyl one product have a mechanical problem with the mechanical strength.
This is a gascet.
In the dependence of the mechanical pressure we have a change of the shielding effect.
Sincerely Yours
F. Gräbner
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I was wondering why Bipolar switching make less EMI comparing to Unipolar switching in SPTG-CPV inverters?
According to a below article, the EMI and leakage current is very low as voltage to ground VPE has no switching frequency component, while only the grid frequency component is present.(see attached picture)
Could anyone add more detailed explanation ?
- Does it mean the grid frequency component is not categorized as noise components so its presence is okay?
- Why does VPE has no switching frequency ?
[Reference]
A Review on Recent Advances and Future Trends of Transformerless Inverter Structures for Single-Phase Grid-ConnectedPhotovoltaic Systems by Kamran Zeb; Imran Khan; Waqar Uddin; Muhammad Adil Khan; P. Sathishkumar; Tiago Davi Curi Busarello; Iftikhar Ahmad; H. J. Kim
Energies, Vol 11, Iss 8, p 1968 (2018)
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Hi Nathalie,
working through pages 10 to 12 of the following paper seems to provide the answer to the question why VPE doesn't have a switching frequency component during bipolar switching:
I still did not complete the reading myself but by providing the link I intend to give you the chance to overtake my slow reading. ;-)
Hope this helps.
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Hi dear engineers,
can anyone help me about above question?
i need technical information on how power cables can effect data or communication (sensitive) cables?
cable electromagnetic interference is main purpose of my problem.
best regards,
Pouyan
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Dear Pouyan,
The inductive interference caused by ac electric traction lines to nearby telecommunication cables has been investigated in this paper: K. J. Satsios, D. P. Labridis and P. S. Dokopoulos, "Inductive interference caused to telecommunication cables by nearby AC electric traction lines. Measurements and FEM calculations," in IEEE Transactions on Power Delivery, vol. 14, no. 2, pp. 588-594, April 1999. In this article there is useful conclusions concerning the influence of the separation distance between the electric traction line and the
telecommunication cable, of the earth resistivity and of the mitigation wires on the inductive interference levels have been obtained, by using a FEM parametric study.
Other important references:
International Telecommilnication Union : "Directives Concerning the Protection of Telecommunication Lines against Harmful Effects from Electric Power and Electrified Railway Lines", vol. I and vol. 11, Geneva 1989.
J. R. Abbott, "HVDC System Simplified Method of Harmonic Coupling Calculation and Testing", /IEEE Transactions on Power Delivery, PWRD-3, April 1988, pp. 839-844.
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I have been reading about Sheltered English Instruction in American school contexts and government attempts to extinguish bilingual education (Proposition 227 - the English-only movement). Is this kind of thinking that is spreading around the world through EMI in higher aducation?
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In fact, I am not quite familiar with other ways of undrstanding EMI, or even it the way it appeared to me is shared by others. Since I am in TEFL field of research, curriculum studies in particular, my actual concerns regards the implications of these policies which are spreading around from goverment to universities here in Brazil. Really, I do worry about the ideology behind Proposition 227. I do not quite agree with it. As well as I have been struggling to forsee what kind of benefits and with what purposes EMI is being thought of to our English language learners in Brazilian universities.
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Wondering if anyone has used one of these before in studies with electrophysiology/psychophysiology recordings in humans. Did they substantially reduce EMI in your data? How did participants feel inside? Thank you. Cheers!
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Faraday tent replaces hermits, solitude in modern conditions. Faraday came up with a simple device to protect against electromagnetic waves of any range. This was necessary for precision work of a certain subject without electromagnetic interference from outside. By the way, before it was enough to retire to a remote village and remain alone with nature. Currently, the Internet and mobile communication network surrounds from all sides even on Mount Everest. There are two main problems of this situation. Humanity does not know whether the pathological contribution makes a permanent electromagnetic effect exceeding the natural background, in the development of such pathological processes as cancer, epileptic status, changes in immunity, fatigue? But there is scientific evidence that the pathological component of increased electromagnetic interference is present. So, the saying that "with a nice person paradise and in a hut" has a weak relation to the tent Faraday. All his life in the tent of Faraday will not live as Diogenes lived in a barrel. It is advisable to unite talented scientists to solve this problem for the future Human.
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I'm looking for a way to calculate the dB of the shielding which use in EMI radiation by using the permittivity and the permeability of the sheilding materials
Is there any equation can I use ?
Thanks for your helping
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Hi Marvin
I intend to prepare a shielding material
Thanks
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How much filler % in matrix for EMI materials is good?
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Very roughly: you can routinely achieve shielding effectiveness of about 20-30 dB wih carbon based fillers (carbon black, graphite, carbon nanotube and their combinations) but that is not too much. 30-40-50 dB can be achiwved with metal-coated glass or carbon fibers or with stainless steel fibers which is almost aceptable. 60-70 dB can be achieved with high quality electroless plating on plastics, which is excellent.
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If the duty cycle variation is large (i.e input voltage and output voltage both are varying (D=00.13 to D=0.96 )) then usage of coupled inductor in multiphase interlieved buck converter is useful from EMI, cost and the ripple reduction point of view??
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The coupled inductor reduces per-phase current ripple that means smaller losses and/or smaller per phase inductance, the output/input current ripple it does not reduce but as it is multiphase structure with interleaved currents the output/input ripple is small. The main drawback is that fast current control loop in each phase is required to prevent saturation of coupled inductors.
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Hello Dr. Long,
My name is Laura MacGregor and I am on faculty at Gakushuin University in Tokyo. I have been researching into EMI at universities in Japan and Vietnam and am now turning my interest to Italy. I am very interested in your work (including your recent presentation at the ICLHE conference - I was not able to attend this year) and also your current teacher training program at the University of Modena. I plan to visit Italy next year in February/March. Would it be possible to meet you then? In the meantime, I would like to ask permission to communicate with you by email as I have several programs. I would also like to tell you about my research project on Italy and what I aim to accomplish. If it were possible for me to conduct part of my research at your university, which involves class observations and interviews with instructors, I would like to discuss that with you as well. I hope that you will email me. With thanks in advance, Laura MacGregor
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Great question thanks
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my question is based on v2g technology.
the block diagram of v2g consist of AC Grid, EMI (electromagnetic interference) Filter, rectifier, PFC, DC_DC circuit and battery. when a 3 phase ac single passes through each of them, what will be the output of each component.
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thanks
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Of particular interest are the needs they may have regarding training and their day-to-day lives working in their schools. I am considering writing my thesis on this topic - the effects of Language Assistant methodology, language and classroom management training on learning results and the feelings of students, teachers and Language Assistants towards EMI and/or CLIL. Thanks!
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How effective is the learning beneffit to bilingual students and what are the assessment metrics. Perhas looking at French-English while conducting a parallel correlation studies.
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I have already consulted this problem with the technician from the company that made & sold us the microscope and he said that it looks like an electrical problem.
He tested the room for EMI prior to installation and it was OK. However he cannot test it now, because the equipment necessary for the retest is expensive and is not fully covered by the warranty and thus we would have to pay for that. So this probably is not an option.
Images made by the technician when the microscope was installed do not show such distortion even at over 100k magnification. 
This distortion is a long lasting problem - 8+ months.
It is present at various magnifications usually from ~30k to 120k and acc. voltages 10, 20 and 30 kV.
I did tests during different days (monday, friday, not weekend) and times of the day (7 a.m., 7 p.m. - different overall load in electrical network).
I also switched off air-condition in both, the microscope's and the adjacent room, switched off the lights and switched to quiet vac. mode.
I also tested with all the conditions mentioned above on the gold-on-carbon test sample.
It happens on all detectors - SE, BSE and STEM.
However,  distortion is still present.
I had an idea that i can somehow extract the frequency of the distortion from the image using FFT - to know if distiortion comes from 50Hz AC, but i do not know any software that can do this.
What else should i try? Any suggestions?
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Hello,
the greeen cable goes to the same spot as the socket.
The freely laying plug is from the second oil pump used for VP mode. 
//UPDATE
i tried to image the sample (gold on carbon) as close to the lens as possible (WD circa 3 mm) and also some TEM grid being literally inside the lens (WD 0.5 mm) and the problem still perists. So does this mean it is a vibration?
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As we no brushless advantages - no maintenance, long working life, no sparking, reduce EMI 
then why not we can use brushless generator 
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There is not a simple answer for that  question.
PMSG are expensive compared to other technologies. Brusless Doubly fed generatorsusually have lower power densities (than regular DFIGs) and this could increse the head mass.in the wind turbine. Cage induction generators have less efficiency and cannot operate at low speed.  
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We have to analyse the radiated and conducted EMI/EMC performance of power electronic circuits. 
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An assessment of conducted emissions can be done using Spice. This is comparatively easy - it can be done with abstracted building blocks of your circuit modeled as voltage sources.
Simulating radiated emissions requires the reproduction of your actual physical circuit. For this I have no recommendation.
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What lab testing experiments, applications or projects are you working on currently that require a "low field environment" to protect sensitive devices or equipment from magnetic field disturbances? Recent applications I have learned about such as TEM, STEM, HRTEM, and ACTEM use electron microscopes which are highly sensitive imaging devices that often require magnetic shielding to prevent malfunction errors.
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We are dealing with very low magnetic fields for Spacecraft on Science missions. Very low means here an order of magnitude of a few nT, far below the Earth magnetic field. Examples for such science missions are SolarOrbiter, JUICE and BepiColombo. We have to perform a magnetic cleanliness programme, starting with the selection of non magnettic materials, magnetically characterize important components and boxes and put the sensitive instruments on a boom in order to gain some distance to the magnetic sources on board the satellite.
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It is easy enough to imagine a situation when wrong layout, bad filtering, and strong electromagnetic field radiated by inductor of a switching converter can disturb the analog part of device to operate correctly. For example, power supply of oscilloscope. However, I never met a systematic study of EMI in mixed-signal systems or ICs. Does such a study make sense? Could EMI be estimated (modeled) in the regular simulators like SPICE or Simulink? It is naturally to assume that some hybrid approach will be needed. I mean simulators of 3D electro-magnetic fields based on finite-elements method.
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Thank you, Vadim. Yes, let us for the sake of simplicity, consider the pair of "transmitter" and "receiver". Of course, there is a "channel" with these or those properties, where interferences pass and interact. This PhD thesis can serve as a good starting point for modelling the on-chip EMI 
E. Backenius, "Reduction of Substrate Noise in Mixed-Signal Circuits," 2007
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i'm interested in finding out EMI problems in different  electronic systems.
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today, many papers focus on EMI modelling. so EMI issue of each systems can be predict and simulate. so EMI issue can be studied easily without measurement setups.
an example of EMI modelling can be find in attached file.
Best regard 
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English Medium Instruction in Higher Education
I am interested in situations when teachers and students are not native speakers of English
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To enhance the skills of students (and teachers as well) in English speaking, we established English Speaking Zones, where students and teachers should talk or speak in pure English and penalties are imposed on those who were heard speaking in the native language.
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Hello.
I have a plan to make new version of Faraday cage for gas discharge circuit. Unlikely to current cage in which radiation sources such as Thyratron and capacitor are just proximate to some electronics related to discharge triggering, This new box will have additional shielding room for these sources as seen in the attached images.
At this moment, I don't know which is good way to get more effective shielding. one image (1st case) shows additional shielding room shares one side to whole Faraday cage while the another (2nd case) is isolated type which is connected to inner surface of the cage via wire.
In 1st case, What I'm worrying is the possibility that EMI directly hits the cage thus cages are all fluctuated in voltage if EMI is severe.
Actually EMI is severe. When we enclose the capacitor with aluminum foil, foil is shaken!
Could you tell me anything about these two design?
In 2nd case, does external surface of the isolated shielding room keep itself equipotent no matter what happens inside?
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Dear Lady,
of course we have unwanted effects. We have the resonances in the Farraday shielded box. It is important, that you know the geometry and the mode and the source frequency, so you can calculate the resonance frequency. In this resonance frequency the shielding have lower values. This is bad.
All the best
F. Gräbner
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We wish to connect a set of 16 microphones to an acquisition board using the coaxial cable RG-174/U. According to the sound source behavior, the microphones will produce amplitudes in the range 8 microvolts - 25 mV, from 200 Hz up to 100 kHz. Since the RG-174/U cable will be near three phase cables and other cables with other kind of signals, electromagnetic interference (EMI) could affect the signal of interest. Does anyone happen to have experimental data on the influence of EMI over the coaxial cable? How can we make sure that EMI will not affect the signals of interest?
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Thank you very much for your comment, Prof. Donggyu Jang. We've seen this pair if double-shield cables called starquad, which minimizes the EMI noise. The residual noise passing through the shield is compensated since it is detected equally by each cable of each pair:
It may be more useful for your needs.
Regards
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Hello, I want to know How to reduce the EMI with Spread spectrum clock technique, Is there any effect on speed of system and rise / fall time ?
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Thanks to all of you for share nice your concept
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Dear all,
Could you please tell me if there is a mathematical model for the power-line interference a(n)*cos(phi(n))? I've found a statistical model for the frequency, but not for the amplitude.
Thank you very much in advance!
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Dear Fernando,
I met with this problem in archaeological prospection (magnetic prospecting - see attached file). From the personal communications with Engin. Faculty scientists follows that they have a solution for ideal sourse, but in real conditions (not horizontal cable location, rugged terrain relief, some other noising factors), they receive abn accuracy of calculations about 20-25%.
Best
Lev
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It detects the presence of EMI coating on spectacle lenses
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Dear Mr. Mannepuli,
this is not a EMC tester. This is only a optical tester of a optical filter.
All the best
F. Gräbner
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In the presence of high EMI, normal sensors pick up too much noise which covers up the true waveform on the oscilloscope. Thus Hall effect sensors are not helpful. Resistive voltage drop sensors yield a low signal to noise ratio !
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Dear Martin, Dear Sujit,
The coaxial shunts are indeed better, but still a common mode current can appearas they are linked to the circuit and mass currents flow trough the circuit, so still a common mode current appears, generating inductive drops elsewhere in the circuit. So it is sometimes better to use a normal shunt with 20nH and 10mohm giving a time constant of 2µs and to compensate that time constant with a 2µs low pass close to the place where you need it. However, all of these methods are invasive in the circuit.
If no precision is needed but just to compare a converter with another identical one, the following trick can be used. This is using a  small SMD inductor (wound I-core) to sense the near field. The smd inductor should be capacitively screened (coax) and loaded with a damping resistor (to avoid resonances with the capacitance of the probe coax). It mainly senses di/dt, but I tried it and one can distinguish also resonances in the drain current and also in the gate current. The advantage is that it is non-contact (no mass current) and non invasive. One still can recognise the duty ratio and even some aspects of parasitic resonances in the supply, or just compare signatures in a qualitative way. However I don't think of using it yet for a reliable current-feedback.
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In XTEM measurements, some ".emi" & ".ser" files of the EDX & STEM analysis are generated. I am unable to read these files, can anybody tell me which program/software can read these files? These .emi and .ser files opened using Notepad but some of the fonts are not readable. 
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You can use Hyperspy:
It is a free, open-source software for advanced data analysis. It runs in both Windows and Linux, it can perform statistical analysis in your data (like PCA) and also many features specific for EDS are available.
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What are the methods to test the effectiveness of material to be used in EMI shielding applications? How much level of conductivity, polymeric composite should be used in EMI shield applications?
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Hallo Mr. Sain,
an intersting method to measure the shielding of a material is the german VG ( military ) standard.
Yours Sincerely
F. Gräbner
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I am new user of HFSS. I am trying to simulate an EBG array to get S21 from port 1 to 2. I am having some problems in assigning boundary conditions and excitations. I am trying to simulate the structure of the IEEE paper attached here but I am not getting proper results.
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thanks sir for the response... the paper that i have attached have the brief of ports placement and the response of simulation... other than that I have made the same design in HFSS 13.0, that .hfss file is attached with this reply.... please check the boundary conditions and coax ports that i have made....
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How do we define the size of anechoic chamber? What are influences? What are the parameters for the selection of size?
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Ensure that no part of any antenna is closer than 1 meter from the walls and 0.5 -0.7 meter from the ceiling of the shielded enclosure. Check these condition with max dimension of the antenna(i.e.,there r so many antennas we may use for testing, so while designing keep in mind the max dimension of antenna which u may use )
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If a high frequency circuit or a high frequency EMP is considered then which method would be the best? Also if the problem includes arbitrary shaped structures (curves).
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Depending of geometry, materials, field sources and frequency range, results of interest, you have three fundamental options: FEM, BEM/MoM/IEM (including their combination) and FDTD/FIT, but sometimes PEEC or TLM may give better results. Electromagnetic modeling is an art. There are no definitive recipes. The most popular isn't always the best approach. You should compare the advantages and drawbacks of these method, in order to choose the best approach, appropriate for your problem. But first of all, understand deeply your problem and (re)formulate it in correct manner. Do not expect valuable answers to vaguely formulated questions.
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Mostly in automotive, these failures are over come in EMI-EMC testing. Normally the unit performs in normal operation but in EMI-EMC testing it fails.
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the mat lab has a FTP tool which will help u to sort out u r problem of calculation.
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The driving profile can be described by a lot of variables like: speed, acceleration,...etc.
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Thanks a lot Eng. Kenneth for your reply. One of the problems of that solution is that the dynamometer has its own radaited emissions as can be seen in Figure 2 in this article http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6050737 !
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The problem is that it is impossible to fix an onboard antenna to receive the electromagnetic disturbances due to the vehicle under test only in all frequency ranges. Such antenna would receive a lot of radiated disturbances from another interfering sources like: other vehicles, WiFi, HiFi, GPS, Bluetooth, Television, Radio, Mobile, Satellite, power lines …etc.
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Thanks Marco for your reply. The problem of using a semi-anechoic chamber provided with a chassis dynamometer is that this type of equipment has its own radiated emissions that will of course interfere with the EMI disturbances due to the vehicle. For more information about this point, I recommend this article: Silva, F.; Aragon, M.; , "Electromagnetic interferences from electric/hybrid vehicles," General Assembly and Scientific Symposium, 2011 XXXth URSI , vol., no., pp.1-4, 13-20 Aug. 2011
Good luck.
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I'm recently working on a UAV project and I encountered this signal loss issue due to the EMI shielding effect of carbon fibers. Is there anyone with some experience on that?
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These shielding effect should be caused by the strong conductivity of carbon fibers themselves, that in turn squeezes EM field on UAV surface, limitating the signal power in arriving to antennas. May you check for different solutions:
1) increase the sensitivity of your antenna, inserting a signal amplifier;
2) transport the antenna outside the body of UAV;
3) put different antennas in all of 4 internal sides of UAV, possibly in direction where there aren't composited parts.