FREQUENTLY ASKED QUESTIONS
Technical Support, Training, and Consulting
- How can I get technical support?
- Do you provide EMI consulting services?
- Do you provide training?
Product Purchase
- What payment methods do you accept?
- What methods do you use to ship?
- Is the software available for download?
- What is typical delivery time?
- What is your return policy?
- How do I place an order?
- Can I purchase over the Internet?
- What is the difference between the previous Radiated Immunity™ program and the new RS Analyst™ program?
Pricing
- Are maintenance contracts available?
- Do I get a price break for upgrades?
- Do you give educational institution discounts?
- Do you have multi-user, site, or network licenses?
Trial and International Versions
- Is an international version of EMI Analyst™ available?
- Is there a demo version?
Post-Purchase FAQ's
- Can I customize the appearance of graphs?
- Can I export EMI Analyst™ results to Microsoft Excel?
EMI Analyst™ FAQ's
- What are the methodology and features of EMI Analyst™?
The FAQs below are based on box-level test setups in which an enclosure can contain multiple circuits, driving multiple cables/loads. For example an EUT comprising a PC, which drives cable-connected external printer, modem and hard drive.
- If the PC/printer, PC/modem, and PC/HD configurations are modeled as separate source/filter/conductors/load models, how is the overall RE response determined? Are propagation velocity factors, phasing and cable radiation patterns due to multiple wavelengths on a cable considered?
- On a PCB, would I need to have trace length, width, and spacing measurements to design a proper filter model?
- Are PCB physical component layout, trace routing, and layer stackup effects modeled?
- Can the effects of uncontrolled return currents, such as from a signal trace crossing a gap in a ground plane or crossing more than one layer on a multi-layered PCB, be modeled?
- When using schematic capture to build a low-pass EMI LC filter model between a low-Z source and a high-Z load, are the effects of a source-L-C-load physical configuration distinguished from that of a source-C-L-load configuration?
- For cable ferrites, can the effects of number of turns be modeled?
- Does RE Analyst™ calculate radiation from enclosures, as well as from cables?
- Are enclosure resonances calculated?
- What is the complexity of cable constructions that can be modeled? For example, can Belden 8166 cable be modeled?
- When comparing the Conductors screenshot for a shielded pair cable with the specs for Belden 9501 cable, how can the wire-to-wire and wire-to-shield distances, as well as the angles theta-1 and theta-2 be determined from the specs? Or must measurements be made?
- In the CE case study, the 200 kHz of the converter is the only frequency. In other EUTs, multiple frequency sources may exist. Does CE Analyst™ account for inter-modulation effects?
- In the CE case study, the source of interference is within the voltage converter circuit being analyzed. Can crosstalk from an unrelated source, e.g., a clock trace also be modeled?
- In the RS case study, only induced DM is considered. Can the induced voltages or currents from CM to DM conversion also be modeled?
- In the RS case study, the 2 m cable is said to be one-half wavelength at 300 MHz.
How so?
- How can actual formal test results or near-field probing be used to improve a model?
- Does EMI Analyst™ perform analyses for EMI/EMC requirement according to RTCA/DO-160?
- I want to do CE. I prototyped the noise coming from my source and below is the result from the spectrum analyzer. How do I turn this graph into something useful that I can put into EMI Analyst™? I also have data for another noisy line that tells me the frequency and the spike peak in dBuV.
- How can the EMI Analyst™ software can help us with EMI filters used in our wiper/engine designs? Nowadays it´s difficult and expensive to develop a filter.
- Can EMI Analyst™ be used to demonstrate the effects on emissions of different shielded cable terminations or shielding, etc.?
- What are the limitations for product support, if one purchases the EMI Analyst™ suite without the maintenance contract?
- Does the software allow for a double shielded cable to be modeled? For example, a twisted shielded wire pair with an overshield.
- Can a cable with several wire pairs be modeled?
- Can solid metal or foil type shields be modeled?
- When building an inverter simulation using Simplorer (or any other circuit analysis tool) to get switch voltage and current waveforms, should I use an ideal switch or a switch with switching losses. The ideal switch would have infinite switching transitions, so it would be the worst case. What do you thing about this concept?
- Does the RS model use hyperbolic functions for its basis of calculation? If so, is there also a simple illustration, or technical reference (application note), you can direct us to?
1. How can I get technical support?
Please refer to the Technical Support page for information about obtaining technical support for any of our software programs.
Technical support is available free of charge for installation-related problems and issues related to proper functioning of the application software.
Consulting support is available on an hourly basis to assist you in setting up and performing EMI analyses using EMI Analyst™. Please contact us for more information.
2. Do you provide EMI consulting services?
Yes, consulting and teaching services are available. Our EMI consultants specialize in solving EMI problems:
- Design guidance
- Troubleshooting
- Computer modeling
- Test support
Please contact us for pricing and consultant availability.
3. Do you provide training?
On-site instruction is available at your facility by our EMI experts. Course content can be tailored to your specific needs and can consist of EMI Analyst™ instruction as well as general EMI control principles.
Please contact us for pricing and scheduling.
4. What payment methods do you accept?
We accept most major credit cards, purchases orders, and company checks for purchases within the United States. Use your Visa, MasterCard, or American Express card to place an order by telephone. Company purchase orders and company checks drawn on a U.S. bank.
5. What methods do you use to ship?
The software is shipped at no cost via Federal Express ground service for most shipments within the United States and Canada. Shipment via FedEx overnight service, United Parcel Service, or U.S. Postal Service is also available.
Please contact us for pricing on shipment methods other than FedEx ground.
6. Is the software available for download?
The software is not available for download at this time. Operation of the software applications requires a hardware key at all times to be inserted in a USB port of the computer on which the software is running. Because the USB key must be shipped to the purchaser the installation disk is also shipped. Most updates are available via download once the original software has been installed from disk.
7. What is typical delivery time?
Software for single-user licenses usually ships next business day. Software for network licenses usually ships 2 days following the order date to allow time for the network USB key configuration. Delivery date is typically 2 -3 business days from the ship date within the continental United States, unless express delivery is arranged at the time of purchase.
8. What is your return policy?
EMI Software is dedicated to providing you with the very best EMI analysis software possible. We are so confident that you will be completely satisfied with our software we offer a full, unconditional refund within 60 days of purchase. If for any reason you are unhappy with the software simply return the installation disk and USB key to EMI Software for a refund.
9. How do I place an order?
Orders may be placed by telephone (310) 371-0133 or fax (310) 371-0133. As a minimum, the following information is required:
- Company Name
- Shipping Address
- Billing Address
- Contact Name
- Contact Phone Number
- Payment Info (credit card number, etc. or copy of purchase order)
- Product(s) and quantity ordered
- License desired
Please contact us for a quotation.
10. Can I purchase over the internet?
At this time we do not provide internet transactions. Orders may be placed by telephone (310) 371-0133 or fax (310) 371-0133. Please see How do I place an order? for more information.
11. What is the difference between the previous Radiated Immunity™ program and the new RS Analyst™ program?
RS Analyst™ retains the best features of Radiated Immunity™ and improves on its modeling capabilities with:
- Improved numeric integration for electrically long conductors
More accurate calculations for high frequencies and better modeling of cabling resonance effects
- Common mode and differential mode modeling
Simultaneous calculations for line-to-line and line-to-ground coupling
- 5 new conductor configurations
Models shielded and unshielded wire pairs over ground plane and other common configurations
- Much larger component library
In addition to resistors, capacitors, and inductors offered by Radiated Immunity™, RS Analyst™ provides ideal and non-ideal models for coupled inductors, transformers, LISNs, and printed circuits
- Shield transfer impedance calculator for braided and solid shields
Values are calculated from shield geometry, construction, and materials
- Shield termination impedance calculator
Calculates parasitic values for non-ideal shield terminations methods
- Expanded conductors and insulators materials supported.
Accounts for permeability, permittivity, etc. for extensive list of electrical materials
- Seamless integration of frequency range, field amplitude, filtering, cabling, shield effects, and loading
12. Are maintenance contracts available?
Yes. Maintenance contracts provide users with the latest upgrades and updates as they become available. Single-user maintenance contracts are priced at 20% of the purchase price if contracted at the time of initial purchase. Please contact us for pricing information on post-sale single-user license and network license maintenance contracts.
13. Do I get a price break for upgrades?
Yes. Upgrade from any previous version and receive a 20% discount. Please contact us for pricing details.
14. Do you give educational institution discounts?
Yes. A discount of 20% is offered to qualified students, faculty, and schools.
15. Do you have multi-user, site, or network licenses?
EMI Analyst™ and its constituent applications, CE Analyst™, CS Analyst™, RE Analyst™, and RS Analyst™, are available as single-user and network licenses.
The single-user license allows the software to be run on one computer at a time. The USB key supplied with the software is required to be present at all times when running the software.
The network license allows the software to be run simultaneously on the number of computers specified by the license. The USB key supplied with the software is required to be present at all times when running the software on any computer on the network.
16. Is an international version of EMI Analyst™ available?
International versions of EMI Analyst™ and its constituent applications, CE Analyst™, CS Analyst™, RE Analyst™, and RS Analyst™, are not yet available. The software runs on the Microsoft Windows operating system and requires a U.S. locale setting. Running the software with a non-U.S. locale setting may adversely affect software operation, particularly for those locales the use a comma as the decimal placeholder, rather than a period decimal placeholder.
17. Is there a demo version?
Yes, an evaluation of EMI Analyst™ is available for download here. Also, you may sign up for a live online demo of the software by clicking here.
18. Can I customize the appearance of graphs?
Yes. The appearance of EMI Analyst™ graphs may be changed in literally hundred of ways.
The EMI Analyst™ Graph form displays calculation results graphically. By default graphs are two-dimensional line graphs.
To change the appearance of a graph, open the Graph Editor dialog by right-clicking anywhere on the graph. Make desired changes. When complete, close the Graph Editor dialog to return to the graph.
For Help on changing the appearance of a graph, open the Graph Editor dialog by right-clicking anywhere on the graph. Select from the tabs on the Graph Editor form the graph characteristic for which you need help and then click the Help button on the Graph Editor dialog.
19. Can I export EMI Analyst™ results to Microsoft Excel?
Yes. EMI Analyst™ generates a table of Frequency/Amplitude pairs for each parameter it calculates. The parameters calculated depend on the analysis being performed, but typically include voltage, current, impedance, and/or field strength. This data can be copied to any program that can accept tabular text data.
To export EMI Analyst™ data to Excel do the following:
- When calculations are complete, display the graph for the voltage, current, field, etc. you wish to export to Excel.
- On the Graph form toolbar click the View Data Table button, , or select Data Table from the View menu. A form containing tabular data for the selected parameter will be displayed.
- Select the Frequency and Amplitude (Current, Voltage, Field, etc.) cells by clicking and dragging the cursor over the data cells you wish to export.
- Copy the cells to the clipboard by clicking the Copy button on the toolbar, selecting Copy from the Edit menu, or pressing Ctl-C.
- Open Microsoft Excel in a new window.
- Paste the data from the clipboard to the Microsoft Excel spreadsheet by clicking the Paste button on the MS Excel toolbar, selecting Paste from the Edit menu, or pressing Ctl-V. The copied cells will appear on the Excel spreadsheet.
20. What are the methodology and features of EMI Analyst™?
All four applications in the EMI Analyst™ suite use a combination of circuit analysis and transmission line theory algorithms to solve the circuits and predict current and voltage at each node of the circuit. The radiated emissions application uses a method-of-moments engine to calculate radiation produced by cable conductors. The radiated susceptibility application uses a transmission line theory engine to perform field-to-wire coupling. Features of the software are summarized on our website here.
The FAQs below are based on box-level test setups in which an enclosure can contain multiple circuits, driving multiple cables/loads. For example an EUT comprising a PC, which drives cable-connected external printer, modem and hard drive.
21. If the PC/printer, PC/modem, and PC/HD configurations are modeled as separate source/filter/conductors/load models, how is the overall RE response determined? Are propagation velocity factors, phasing and cable radiation patterns due to multiple wavelengths on a cable considered?
Since the radiation from each cable is generated by different circuits, operating at different frequencies and having different spectral content, the radiation from each cable is not additive. Simply overlaying the results of each analysis should provide the net radiation from the system. There may be moments when the radiation pattern from one cable adds constructively with the radiation from another cable, but unless the circuits producing the radiation on both cables are time and phase synchronized (not usually the case) the radiation from each will not be additive.
22. On a PCB, would I need to have trace length, width, and spacing measurements to design a proper filter model?
EMI Analyst™ uses the time-domain waveforms of the circuit as the basis for its calculations. This trace current and/or voltage information can be obtained from measurement or 2D signal integrity simulation tools.
23. Are PCB physical component layout, trace routing, and layer stackup effects modeled?
EMI Analyst™ doesn't calculate the effects of the PWB trace layout on the circuit waveforms. It uses the time domain waveform at the point where the filtering and cabling connects to the circuits as the basis for its EMI calculations. Dedicated 2D and 3D EMI and SI field solvers are available for observing the fields on a PCB.
24. Can the effects of uncontrolled return currents, such as from a signal trace crossing a gap in a ground plane or crossing more than one layer on a multi-layered PCB, be modeled?
This falls into the realm of PWB finite analysis programs and is outside the scope of EMI Analyst™. There are many 3D quasi-static and full-wave field solvers that are optimized for this analysis. Remember, most EMI problems are cable related. In my experience, PWB-related EMI problems are rare if the PWB is housed in a metal enclosure, which is usually the case for military hardware. Even for commercial hardware, where the PWB is in a plastic case, the biggest EMI problems are cable-related. Only at high frequencies does PWB layout become problematic, and many of those problems can be prevented by good PWB layout practices (like not running traces over gaps in the ground plane.)
25. When using schematic capture to build a low-pass EMI LC filter model between a low-Z source and a high-Z load, are the effects of a source-L-C-load physical configuration distinguished from that of a source-C-L-load configuration?
Absolutely. EMI Analyst™ takes into account the impedance of the source, the load, and the filter components when performing it calculations.
26. For cable ferrites, can the effects of number of turns be modeled?
EMI Analyst™ models ferrites using the impedance characteristics of the ferrites, so as long as you can provide the impedance values for multiple turns, it can incorporate the effect of multiple turns in the analysis. Since the impedance increases approximately as the square of the number of turns, this information can be estimated from ferrite core data sheets or better yet from network analyzer plots.
27. Does RE Analyst™ calculate radiation from enclosures, as well as from cables?
No, just cables. However, since cables are electrically long compared with printed circuit board traces cables are generally the most significant source of radiated emissions.
28. Are enclosure resonances calculated?
Enclosure shielding and resonance calculations are outside the scope of EMI Analyst™. See the previous FAQ.
29. What is the complexity of cable constructions that can be modeled? For example, can Belden 8166 cable be modeled?
EMI Analyst™ currently has eight cable configurations available: unshielded wire pair, unshielded wire over ground plane, shielded single wire, unshielded wire triple, unshielded wire pair over ground plane, shielded single wire over ground plane, shielded wire pair, and shielded wire pair over ground plane. Shields may be woven wire braid or solid, i.e. foil.
30. When comparing the Conductors screenshot for a shielded pair cable with the specs for Belden 9501 cable, how can the wire-to-wire and wire-to-shield distances, as well as the angles theta-1 and theta-2 be determined from the specs? Or must measurements be made?
Typically the wire gauge and shield diameter can be extracted from the data sheets. The thickness of the dielectric is sometimes specified or can be estimated from a cross section diagram. Measurements are great if you have a sample of the cable. The angles on the Conductors form are simply used to calculate the wire-to-wire separation.
31. In the CE case study, the 200 kHz of the converter is the only frequency. In other EUTs, multiple frequency sources may exist. Does CE Analyst™ account for inter-modulation effects?
No. If inter-modulation is a concern the user would have to make this assessment from the separate analyses.
32. In the CE case study, the source of interference is within the voltage converter circuit being analyzed. Can crosstalk from an unrelated source, e.g., a clock trace also be modeled?
EMI Analyst™ does not perform crosstalk calculations. However, one could perform rudimentary crosstalk analysis using capacitive or inductive coupling, and then enter the coupled waveform as a Source in EMI Analyst™.
33. In the RS case study, only induced DM is considered. Can the induced voltages or currents from CM to DM conversion also be modeled?
Yes. EMI Analyst™ simultaneously calculates common mode and differential mode current and voltage, so if CM to DM conversion is taking place, it will be calculated.
34. In the RS case study, the 2 m cable is said to be one-half wavelength at 300 MHz.
How so?
Oops. Thanks for catching the error. Should have said 2 m cable is one-half wavelength at 75 MHz. (Must have multiplied by 2 when we should have divided by 2.)
35. How can actual formal test results or near-field probing be used to improve a model?
In-circuit measurements of current using an RF current probe can be very helpful! Since EMI Analyst™ provides the calculated current through every circuit branch in the model, the model can be refined using available measurement data.
36. Does EMI Analyst™ perform analyses for EMI/EMC requirement according to RTCA/DO-160?
EMI Analyst™ has the ability to perform calculations for the following sections of RTCA/DO-160:
Section 18 – Audio Frequency Conducted Susceptibility
Section 20 – Radio Frequency Susceptibility (Radiated and Conducted)
Section 21 – Emissions of Radio Frequency Energy
37. I want to do CE. I prototyped the noise coming from my source and below is the result from the spectrum analyzer. How do I turn this graph into something useful that I can put into EMI Analyst™? I also have data for another noisy line that tells me the frequency and the spike peak in dBuV.
There are a couple of ways you can approach the modeling. One is to measure the spectrum as you have here and then use the Source module in EMI Analyst™ to create a time domain waveform that has a frequency domain spectrum that matches your measured values. This method can take a little trial and error to achieve good correlation. Another approach is to measure the time domain waveform using an oscilloscope, then using the Source module create a time domain waveform that matches your scope waveform. This is probably a faster method. Since you have a spectrum analyzer you can verify the calculations of the Source module to make sure your calculated and measured spectra match. It might be helpful to change your spectrum analyzer settings slightly to increase the dynamic range and number of spectral components. As a start you might consider changing the reference level from 107 dBuV to 70 dBuV, change the Start Frequency from 0 Hz to 500 kHz, change the Stop Frequency from 3 MHz to something like 10.5 MHz (this makes each horizontal division 1 MHz), and change the resolution bandwidth to something like 1 kHz (which will drop the noise floor, allowing you to view more harmonics of your 525 kHz waveform.
38. How can the EMI Analyst™ software can help us with EMI filters used in our wiper/engine designs? Nowadays it´s difficult and expensive to develop a filter.
EMI Analyst™ software can definitely help you in developing EMI filters for automotive (or any other industry) applications.
EMI Analyst™ allows the design engineer to model the complete system circuit to get a clear prediction of how the EMI filter will perform. The complete circuit is comprised of four elements: the EMI noise source (the wiper motor or the cooling pump motor in the examples you mentioned), the EMI filter, the wiring connected to the equipment, and the load or source circuit to which the device is connected. As you may be aware, it is necessary to model the complete circuit, not just the EMI filter, to get an accurate prediction of EMI performance.
EMI Analyst™ allows the noise source to be modeled using time-domain waveforms, which can be obtained using oscilloscope measurements, circuit analysis programs, or from circuit data sheets. The software converts these time-domain waveforms into frequency-domain spectra for EMI analysis. The EMI filter is created using a schematic capture program built into EMI Analyst™. Just about any EMI filter that can be modeled using passive components can be synthesized.
The wiring and load/source circuit are similarly modeled to accurately simulate the impedance characteristics of equipment connected to the circuit under investigation, since the impedance of interfacing equipment has a significant effect on EMI filter performance.
Once a model of the complete circuit has been built, the conducted emissions, radiated emissions, conducted susceptibility, and radiated susceptibility performance can be calculated. Evaluating various EMI filter topologies and component values is quick and simple. EMI Analyst™ supports all known frequency-domain automotive (and other industry) EMI requirements.
39. Can EMI Analyst™ be used to demonstrate the effects on emissions of different shielded cable terminations or shielding, etc.?
EMI Analyst™ can quickly show differences between any competing design alternatives. For example, the graphs shown below show predicted radiated emissions for a motor inverter that uses a motor drive cable whose shield is grounded using 360-degree terminations (left-hand graph) and using 100 mm pigtail type terminations (right-hand graph).
 
40. What are the limitations for product support, if one purchases the EMI Analyst™ suite without the maintenance contract?
Installation support and clarification support are provided at no cost. Installation support involves any issues that might arise as a result of installing the software on a PC. Clarification support covers questions related to software capability, topics that may not be adequately explained in Help files, and issues related to operating the software.
Technical support questions, such as how to model specific circuits, components, etc., how to interpret results, or questions of an EMI consulting nature, are billed at an hourly rate of $150.00 per hour. Time is billed only for actual time expended, in 1/10th-hour increments. Technical support requires prior receipt of a Purchase Order or equivalent.
The EMI Analyst™ software package has been designed to be intuitive to learn and use. Given your background in EMI you should have no trouble coming up to speed and using the full capabilities of the software.
If your budget allows, you should consider a maintenance contract. We are improving the software all the time. A maintenance contract will provide you with periodic updates and ensure that you always have the latest new features and capabilities.
41. Does the software allow for a double shielded cable to be modeled? For example, a twisted shielded wire pair with an overshield.
Presently, EMI Analyst™ does not have the capability to analyze double shielded cables, but double shielded cables will be added in the future.
42. Can a cable with several wire pairs be modeled?
EMI Analyst™ performs calculations on one circuit at a time, one wire pair at a time. This results in a conservative analysis since and shielding or loading effects of other wires in the cable bundle are not taken into account in the analysis.
43. Can solid metal or foil type shields be modeled?
EMI Analyst™ has the capability to model braided cable shields or solid shields such as conduit or metal foil. The shield transfer impedance is calculated using dimensional and shield material information entered by the user. Shield transfer impedance values can also be entered numerically to accommodate vendor-supplied or measured values.
44. When building an inverter simulation using Simplorer (or any other circuit analysis tool) to get switch voltage and current waveforms, should I use an ideal switch or a switch with switching losses. The ideal switch would have infinite switching transitions, so it would be the worst case. What do you thing about this concept?
Although using an ideal switch will give worst case results it may not be the best way to go. If the ideal switch has zero rise time and zero fall time the high frequency emissions will be much greater than real world. This may result in EMI predictions that shows radiation exceeding the RE limits by many 10's of dB at high frequencies. Since you are going to the trouble of doing Simplorer simulations and EMI Analyst™ predictions, take advantage of EMI Analyst™'s ability to model non-ideal waveforms that simulate as closely as possible the real hardware.
45. Does the RS model use hyperbolic functions for its basis of calculation? If so, is there also a simple illustration, or technical reference (application note), you can direct us to?
The field-to-wire coupling calculations in Radiated Immunity use transmission line theory, which employs hyperbolic functions. An excellent technical reference on this subject is a book by Albert A. Smith, "Coupling of External Electromagnetic Fields to Transmission Lines."
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