In Compliance: The Compliance Information Resource for Electrical Engineers logo
EMC and Safety
for Installations
Developments in Ground Bonding Networks
PLUS
Non-IP Networking: Why the Industry Needs a Framework

Firmware: The Inexpensive Way to Address EMC Issues

Safety Outside the Box: Going Beyond the Standard Specific to Your Equipment

2021 Product Resource Guide text
PLUS
Non-IP Networking: Why the Industry Needs a Framework

Firmware: The Inexpensive Way to Address EMC Issues

Safety Outside the Box: Going Beyond the Standard Specific to Your Equipment

2021 Product Resource Guide text
October 2020
October 2020
Volume 12 l Number 10
Contents
Developments in Ground Bonding Networks
By Keith Armstrong
In Part 1 of this two-part article, we’ll discuss the development of “grounding networks” and the shift to meshed structures to reduce damage from overvoltages. Part 2 will appear in our November 2020 issue.
By John Grant
The last thirty years have seen great strides in the deployment of communication network infrastructure. With an increasing emphasis on power-efficient communication for a growing variety of applications, there is a rising awareness that an alternative to IP might need investigation.
By Claudio Stazzone
Firmware is integral to the operation of most devices, and may represent an easier and less expensive pathway for addressing EMC issues. This article presents different approaches to modifying firmware as well as case studies illustrating the potential effectiveness of this approach.
Going Beyond the Standard Specific to Your Equipment
By Dan Roman
This article discusses additional requirements that designers and safety professionals may want to consider beyond the base standard for their product based on the environment and user exposure.
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hands texting
computer hardware
lightbulb coming out of a box
2021 Product Resource Guide text
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In Compliance Magazine
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editor/
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Lorie Nichols
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senior contributors
Bruce Archambeault
bruce@brucearch.com
Leonard Eisner
Leo@EisnerSafety.com
Daryl Gerke
dgerke@emiguru.com
columns contributors
EMC Concepts Explained
Bogdan Adamczyk
adamczyb@gvsu.edu
Hot Topics in ESD
EOS/ESD Association, Inc
info@esda.org
On Your Mark
Erin Earley
eearley@clarionsafety.com
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compliance news
FTC Proposes Rulemaking on “Made in USA” Labeling
The U.S. Federal Trade Commission (FTC) has proposed requirements that would require manufacturers to qualify all “Made in the USA” claims on packing and marketing materials for their products.

According to a Notice of Proposed Rulemaking (NPRM) published in the Federal Register, a “Made in the USA” claim can only be used in cases where “the final assembly or processing of the product occurs in the United States, all significant processing of the product occurs in the United States, and all or virtually all ingredients or components of the product are made and sourced in the United States.” The requirement applies to comparable claims for products using words including “manufactured,” “built,” “produced,” “created” or “crafted.”

Producers who promote or offer for sale products as “Made in the USA” that do not meet all of these conditions can be found to have engaged in unfair or deceptive practices under FTC regulations, and therefore subject to civil penalties.

FCC, Other Federal Agencies, Join Forces for Rural Telehealth
The U.S. Federal Communications Commission (FCC) and other federal agencies are joining forces to increase access to telehealth solutions in rural areas across the U.S.

According to a Memorandum of Understanding (MOU), the FCC, along with the U.S. Department of Health and Human Services (HHS) and the U.S. Department of Agriculture (USDA) will work together to develop and implement a joint Rural Telehealth Initiative intended to “address health disparity issues, resolve service provider challenges and promote broadband services and technology in rural areas of America.”

Under the terms of the MOU, the agencies have agreed to establish an interagency Rural Telehealth Initiative Task Force comprised of representatives from each agency and charged with developing a formal plan for the Initiative, consistent with the respective missions and authority of each partner agency. The Task Force will serve as a forum for the exchange of agency expertise, as well as relevant scientific and technical information, data and publications.

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DILBERT © 2020 Scott Adams. Used By permission of ANDREWS MCMEEL SYNDICATION. All rights reserved.
EMC concepts explained
Measuring Differential- and Common-Mode Current Radiation from Cables
By Bogdan Adamczyk
This month’s column is a revised version of the August “EMC Concepts Explained.” In the interest of clarifying several points within the column, the author presents an updated version for In Compliance readers.
T

his article discusses the common-mode and differential-mode radiation from cables and presents the measurement results from the SMPS connecting wires.

Differential-Mode and Common-Mode Circuit Model
Consider a typical circuit model shown in Figure 1.

If the fields generated by the forward current cancel the fields of the return current and no other circuits, or sources, or coupling paths are present, then the forward current equals the return current. In virtually any practical circuit, a different scenario takes place, as shown in Figure 2.

ÎD is referred to as the differential-mode (DM) current while ÎC is referred to as the common-mode (CM) current. The DM currents are usually the functional currents. They are equal in magnitude and of opposite directions. The CM (unwanted) currents are equal in magnitude and of the same direction (See [1] for the discussion of the CM current creation).

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Backed by a 25-year performance warranty, these absorbers do not absorb humidity, which can alter performance characteristics over time and compromise measurement accuracy.

Our test chamber design also minimizes the risk of exposing operators to high-power electromagnetic fields leaking out of the chamber. This benefit is derived from our pan-type RF shielding construction instead of the traditional wood-core construction, which over time can swell and degrade shielding performance.

To find out more about the safest choice in chambers and absorbers, call us at 215-723-8181, or visit www.arworld.us/Chambers.

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hot topics in ESD
FinFETs AND THEIR IMPACT ON ESD PROTECTION DESIGN
By Dr. Mirko Scholz for EOS/ESD Association, Inc.
F

or 2020, TSMC is targeting to start mass production of its first 5 nm technology. Also, at this node FinFETs are the transistor architecture of choice. In this article, we will introduce FinFETs and their advantages over planar transistors. We will discuss some of the ESD protection design challenges when designing in a FinFET technology and give an outlook on the successors of FinFET.

What are FinFETs? Why do we need them?
For many years, the technology scaling has followed Moore’s law. In the past, transistors were made with a planar device architecture. Silicon oxide was the dominating gate oxide. During technology scaling, the reduction of the gate-oxide thickness resulted in an increase in the gate leakage current because of quantum-mechanical tunneling. Then people started to wonder if Moore’s Law that guided the technology scaling for generations would come to an end. This gave birth to what is known as FinFET [1]. The features of this device development are explained below.
banana skins
Numbers 291 – 294 are taken from the Appendix to MIL-STD-464A dated 18 March 1997. (MIL-STD-464A is entitled “Department of Defense — Interface Standard —Electromagnetic Environmental Effects — Requirements for Systems”.)
291
From MIL-STD-464A A.5.6.1 “Non-developmental items (NDI) and commercial items”

Several instances have been noted in ground-based applications where EMI emissions from commercial digital processing equipment have interfered with the operation of sensitive radio receivers. Of particular concern are radiated emissions from processor…

292
From MIL-STD-464A A.5.14 “EM Spectrum Compatibility”

Currently there are numerous incidences of co-site, intra-ship, and inter-ship interference, as well as interference with the civilian community. For example, the Honolulu Airport air traffic control radars have been degraded by shipboard radars…

293
From MIL-STD-464A A.5.7 “Electrostatic charge control”

A maintenance person was working inside a fuel tank and experienced an arc from his wrench when removing bolts. It was found that maintenance personnel were routinely taking foam mats into the tank to lie on while performing maintenance…

294
From MIL-STD-464A A.5.7.1 “Vertical lift and in-flight refueling”

To protect personnel on the ground from receiving electrical shocks, it is standard practice for rotorcraft to touch the ground with the hook before it is connected to the cargo. As the cargo is lifted, the whole system (aircraft and cargo) will become…

on your mark
ISO/TS 20559: A Systems Approach to Safety Communication
By Erin Earley
How the International Organization for Standardization’s Recently Published Technical Specification 20559 Can Be Applied to Products
T

his summer, the International Organization for Standardization’s Technical Committee in charge of standards for safety signs and symbols, ISO/TC 145, published a new Technical Specification, ISO/TS 20559 Graphical symbols – Safety colours and safety signs – Guidance for the development and use of a safety signing system.1 This new international specification focuses on workplace safety sign systems. Yet many of its underlying concepts speak to various forms of safety communication meant to reduce risk in today’s world – including product safety labeling. In this article, we again go behind-the-scenes with insight from Geoffrey Peckham, the chairman of ISO/TC 145 and long-time member of the ANSI Z535 committee (as well as the founder of Clarion Safety Systems and the original author of this “On Your Mark” column).

The Overall Objective: Safety Communication that Leads to Risk Reduction

According to ISO/TS 20559’s scope, it provides “recommendations and explanations on the practical application of safety signs to form a system of communication intended to reduce risk.” Safety signs and labels are basic communication tools used by organizations to lessen risk – but their risk reduction benefits are only fully achieved when these communication tools are designed correctly from the beginning, or, if already installed, replaced by signs and labels that meet the latest best practice industry standards. The new ISO technical specification, ISO/TS 20559, thoroughly describes the visual components that make up best practice “systems” of signage, making it an essential document for organizations to use to better manage risk.

Feature Article
EMC and Safety for Installations: Part 1
Developments in Ground Bonding Networks
By Keith Armstrong
EMC lab
Editor’s Note: In this article, the words “ground,” “grounded” or “grounding” are used interchangeably with “earth,” “earthed,” or “earthing.”
EMC1 for Systems and Installations

As the quantity and variety of electronic equipment used in systems and installations continues to grow, EMC is becoming an increasingly important issue. Almost all my work on systems and installations since 1990 has been involved with items of equipment interfering with the correct operation of other items on the same site.

In 1990, variable speed motor drives using insulated gate bipolar transistors (IGBTs) and power field-effect transistors (PowerFETs) for high-speed power switching were very new, as were private mobile radio systems, and they both caused many problems with legacy electronic equipment. Since then, EMC standards and regulations in most countries have considerably improved the emissions and immunity of equipment, but at the same time, variable speed motor drives have constantly improved – by switching faster. Faster switching makes them more efficient, smaller and less costly, with the result that they are being used much more widely. Unfortunately, switching faster causes increased noise emissions at higher frequencies, increasing the possibilities for interfering with other equipment (see Figure 1).

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GOING BEYOND THE
STANDARDS OF EMC COMPLIANCY.
The future is here! From driverless vehicles and drones delivering pizzas, to ear buds that act as virtual mixing boards for real-world audio, our lives are increasingly dominated by EMC. So, too, is ETS-Lindgren’s work in compliance testing and measurement, transcending the standards of EMC performance – Beyond Measure.

As an international manufacturer of market-leading components and systems that measure, shield and control electromagnetic and acoustic energy, ETS-Lindgren is the driving force that allows some of the biggest industry names, and latest technological advances, to meet compliance standards. From chambers to test cells, absorbers, positioners and antennas, ETS-Lindgren’s EMC solutions are designed for reliability, diversity, scale and precision.

More importantly, our ability to create real-world test scenarios, troubleshoot potential failures and maximize the chance of passing standards within the allotted time and budget; helps our customers bring life-changing products to market – faster.

To view our accreditations and case studies, visit our website at ets-lindgren.com.

BEYOND MEASURE.™
Visit us, follow us, watch us, and connect with us at:

Facebook logoTwitter logoYoutube logoLinkedin logo

GOING BEYOND THE
STANDARDS OF EMC COMPLIANCY.
The future is here! From driverless vehicles and drones delivering pizzas, to ear buds that act as virtual mixing boards for real-world audio, our lives are increasingly dominated by EMC. So, too, is ETS-Lindgren’s work in compliance testing and measurement, transcending the standards of EMC performance – Beyond Measure.

As an international manufacturer of market-leading components and systems that measure, shield and control electromagnetic and acoustic energy, ETS-Lindgren is the driving force that allows some of the biggest industry names, and latest technological advances, to meet compliance standards. From chambers to test cells, absorbers, positioners and antennas, ETS-Lindgren’s EMC solutions are designed for reliability, diversity, scale and precision.

More importantly, our ability to create real-world test scenarios, troubleshoot potential failures and maximize the chance of passing standards within the allotted time and budget; helps our customers bring life-changing products to market – faster.

To view our accreditations and case studies, visit our website at ets-lindgren.com.

BEYOND MEASURE.™
Visit us, follow us, watch us, and connect with us at:

Facebook logoTwitter logoYoutube logoLinkedin logo

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10/20 RR © 2020 ETS-Lindgren v1.0

Feature Article
Non-IP Networking: Why the Industry Needs a Framework
By John Grant
Someone networking on their phone
T

he last thirty years have seen great strides in the deployment of communication network infrastructure. That growth is primarily due to the establishment of the IP protocol as a stable specification in the late 1970s. There have been many benefits to using an IP-based approach, and today all manner of different communications networks rely on its widespread adoption. That said, with an increasing emphasis on power-efficient communication for a growing variety of applications, there is a rising awareness that an alternative to IP might need investigation.

The Rise of TCP/IP

Since its formation, the TCP/IP protocol suite is responsible for creating the heart of the internet. The transport control protocol (TCP) deals with the transportation of data, the process of dividing up messages into packets and then reassembling them after transmission. The internet protocol (IP) takes care of the addressing and routing of the packets transmitted across a communications network of attached devices.

The TCP/IP protocol suite has seen many iterations to its specification over the years. Still, one of the guiding principles from its conception was that the endpoints occupied fixed positions and that their connections would remain unchanged. Increasingly, the networks in place today see that endpoints do move, and connections may be dropped and re-established depending on several criteria.

Feature Article
Firmware: The Inexpensive Way to Address EMC Issues
By Claudio Stazzone
Firmware: The Inexpensive Way to Address EMC Issues

I

n more than ten years working in labs as an EMC engineer, the majority of devices and systems I have tested include two important elements that interact with each other, thereby allowing the equipment under test to work. Electronic boards and firmware. It is difficult to imagine an electronic board without firmware running in a microcontroller. Even a simple wall charger for batteries has integrated firmware to switch the behavior of the charger from constant voltage to constant current, and to switch into trickle charging or to begin the discharge process.

Over the years, I’ve come to think of firmware as the soul of every electronics board since, without firmware, almost every PCB would be “dead.” But because firmware is now so deeply embedded into the working mode of a device, what is the influence, if any, on a device’s EMC performances? Could, in theory, at least, a device using different firmware versions behave differently during EMC measurements? We’ll explore that question in this article.

Feature Article
Safety Outside the Box
Going Beyond the Standard Specific to Your Equipment
By Dan Roman
Lightbulb coming out of a box

Editor’s Note: The paper on which this article is based was originally presented at the 2018 IEEE International Symposium on Product Safety Engineering in San Jose, CA. It is reprinted here with the gracious permission of the IEEE. Copyright 2020 IEEE.

Y

ou have designed your product and need to go through the testing, declarations and certifications to market it in your target countries and regions. You look through the harmonized standards in the Official Journal of the European Union that the Low Voltage Directive 2014/35/EU [1] calls out for presumption of conformity. You also contact safety agencies in other countries and regions where your product will be sold and get determinations of required standards and certifications.

Is it enough? Most likely it is not. Technology and entertainment products are pervasive in the home and, while parents are expected to protect their child, supervision may not always prevent or minimize significant injury. In today’s litigious society, you have done the bare minimum if you have followed the steps in the previous paragraph. Plaintiff’s attorneys will be more than glad to point out that you did the minimum required.

Designers and compliance engineers must do their due diligence and look beyond the base standards and minimum requirements. This paper will not give you every possible scenario to consider in the design and use of your product, but it is the author’s intention to get you to think “outside the box” of the minimum requirements with some basic due diligence and risk assessment methodologies.

2021
Product
Resource
Guide
Contents
Contributing Author
Don MacArthur
Principal EMC Consultant
MacArthur Compliance Services, LLC.

The process of making informed purchasing decisions can be quite complex. From absorbers to testing, today’s compliance engineer must be knowledgeable and well-versed in what to look for when selecting products and services that will work best for your needs.

This is where the Product Resource Guide comes in. In this year’s Guide, we highlight eight product categories—offer guidance on the use of these products—and selection tips on how to choose the right product or service for your applications.

So, whether you’re simply looking to replace an old piece of equipment, or are fully outfitting a brand-new lab, the Product Resource Guide is here to help.

We hope you’ll find the 2021 Product Resource Guide an invaluable resource that you keep handy year ‘round.

Lorie Nichols text
Editor/Publisher
Absorbing
Materials
RF Absorber Power Handling and Safety Considerations
Y

ou understand how RF absorber works, appreciate why its pyramidal shape influences performance, can describe how it’s specified for performance, know how to select the correct length and shape for your application, and understand how it is manufactured and how the manufacturing process affects absorber quality. These are all great attributes of RF absorber that you must take into consideration when properly outfitting an anechoic chamber for EMC testing purposes. But have you also considered safety attributes, including the maximum power handling capability the absorber will need to meet in your application and also its flammability rating? The safety performance specifications of RF absorbers are just as important as the other attributes of RF absorber performance. Let’s talk about them next.

Normal Power Handling Capability (Polyurethane Based Absorbers)
Polyurethane based absorbers withstand a maximum power of 0.5W/in2 continuous wave (CW) illumination in a normal temperature environment with no additional forced air movement. To give some perspective, for the plane wave/far electric field (E-field) condition, this amounts to roughly 540 V/m of E-field. These types of RF absorbers can safely handle up to 90°C temperature without permanent damage. If a greater field strength than 540V/m is expected, then a more porous foam-based absorber may be required for higher power handling capability. These types of absorbers are known as filtered foam absorbers. We’ll look at these in the next paragraph.
Tips for Selecting
Absorbers
  1. Know how anechoic absorber works. Absorber is designed to reduce reflections from impinging electromagnetic (EM) waves, and “absorb” incident EM energy.
  2. Match absorber design to application. Absorber works by dissipating the EM energy inside the absorber and turning it into heat. In most RF, microwave and antenna applications, the lossy dielectric works best because of superior EM absorption at higher frequencies.
  3. Pyramidal shape influences absorber performance. Broadband absorbers work by avoiding “sudden” changes in impedance for the impinging wave and gradually terminate and absorb the EM wave.
  4. Specify absorber for RF performance. Absorber is specified for reflectivity as a function of frequency at normal incident angle. Understand that reflectivity degrades at larger incident angles
  5. Match absorber length and shape for your application. Pyramidal absorber length determines how well it can work at the lowest frequencies.
  1. Use commonly available absorber lengths. Save money, speed delivery by choosing absorber in typical, off the shelf lengths.
  2. Determine maximum power handling capability of absorber. Polyurethane absorbers are specified to withstand a maximum power of W/in2 of continuous wave (CW) incident field under room temperature with no additional forced airflow.
  3. Manufacturing process impacts absorber quality. Find a computer controlled manufacturing process that begins with homogeneous blocks of polyurethane foam.
  4. Use non-hygroscopic absorber. Maintain a stable absorber electrical property and RF reflectivity by reducing moisture, which affects electrical conductivity significantly.
  5. Confirm RF performance verification testing. Ask how your supplier tests the absorber to verify performance reflectivity before shipment. Is each piece of absorber tested or sample tested one piece per batch? Is each piece serialized? Ask these questions protect your investment!
These tips are presented by
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Amplifiers
Selecting the Proper RF Amplifier for the Required Field Strength
A

sk any experienced EMC test engineer or technician what one of the most frequently asked questions they get is and they’ll probably tell you something along the lines of the following:

“With the current broadband RF amplifier and antenna combination we have, what’s the highest field strength obtainable?”

The requestor is usually trying to find equipment that generates some enormously high field strength level to test their product, probably already knowing beforehand that the existing amplifier/antenna combo is not suitable.

The main reason the antenna/amplifier combo chosen is probably not adequate is because we usually only purchase what we need at the time. More power costs more money when it comes to broadband power amplifiers, so we typically only specify/buy to meet our current needs rather than what we may need in the future. This is a common cost-limiting approach practiced in most EMC test facilities.

Tips for Selecting
Amplifiers
  1. Determine the Frequency range of operation needed, sometimes more than one amplifier is required.
  2. Determine if you need a Pulse or CW type of Amplifier. Example: HIRF EMC applications require High Power Pulse Amplifiers.
  3. Determine the minimum power needed from the amplifier. Example: As you go up in frequency, antenna gain improves, so a lower power amplifier may be acceptable.
  4. Assess the system losses between the amplifier and the Antenna/DUT. Example: If the test setup has 6dB of losses, then the Amplifier power needs to be 6dBm higher.
  1. Some modulations, if required for the test application, would require a higher power amplifier. Example: When performing an 80% AM modulation test, the amplifier needs to have 5.1dBm of margin to accommodate the peak.
  2. Antennas, Cables, DUTs & Rooms have cumulative VSWR. It is best to allocate for some power margin.
  3. Consider the application, is this a single test or will it be used repetitively.
  4. Consider your desired RF connection types and locations optimal for your application.
  5. Also consider if automation will be used so the appropriate remote capability is included.
These tips are presented by
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Antennas
Baluns
Ever heard the term “balun” and wondered what it meant? If that’s the case, please read on.
Balanced/Unbalanced
The term balun is a portmanteau (a blending of two words) of balanced/unbalanced – BAL-UN.

A balun transformer is used in antennas for matching the wideband impedance of the antenna to that of the amplifier. It is often the balun that determines the maximum amount of power that can be delivered to an antenna used for EMC testing purposes. Balun equipped antennas can also be used for radiated emissions testing.

Bilog antennas (ironically also portmanteau for biconical/log-periodic – BI-LOG) or just a plain biconical or plain log-periodic antenna must be protected against accidental damage during EMC compliance testing. A balun transformer, located at the antenna’s feed-point, limits the power-handling ability of the antenna because some of the power delivered to the antenna ends up as heat in the core and windings.

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Chambers
Important Considerations When Installing, Tearing Down and Moving an EMC Chamber
I

f you’re technically-minded and involved in EMC testing, then you’re probably well aware of all of the nerdy things involved in running an EMC test facility, properly outfitted with the best semi-anechoic chamber(s) and associated test equipment and cabling. To the exact letter of the law (i.e., standard), you already know how to set up and perform an accurate and repeatable radiated emissions or RF immunity scan. You know how ferrite tile and RF absorber works and which antenna(s) work best for each particular type of EMC test. You’re an expert at EMC testing but, when it comes to installing, tearing down, and moving an EMC chamber, you may not have a clear understanding of all of the non-engineering tasks that go along with such an important event.

You should know that if certain items are overlooked, then a chamber install can quickly go off track and result in a non-ideal, incomplete, unusable chamber that doesn’t fully meet your EMC testing needs.
You may be asking yourself; I’m on the technical side, why should I care about all of this non-engineering stuff? You should know that if certain items are overlooked, then a chamber install can quickly go off track and result in a non-ideal, incomplete, unusable chamber that doesn’t fully meet your EMC testing needs. Incomplete installations often require rework and result in schedule delays and cost overruns that negatively impact your company’s bottom line.
Tips for Selecting
Chambers
  1. Selection of a chamber is determined by the standard being tested to. Some types of EMC Chambers are: Commercial, MIL STD/DO-160, CISPR 25 and Reverb.
  2. Commercial chambers are used for IEC and CISPR standards for Emissions and Immunity testing. Typically, “Semi – Anechoic” and achieve CISPR16 (Emissions) and IEC 61000-4-3 (Immunity) chamber performance requirements.
  3. Semi-Anechoic Chambers are strategically lined with absorber and ferrite to meet specifications without fully lining all surfaces.
  4. Verification for CISPR 16 compliance is Normalized Site Attenuation (NSA) (26 MHz-1 GHz) and Site Voltage Standing Wave Ratio (sVSWR) (1-40 GHz). This verifies the chamber “Quiet Zone”. Quiet zones are normally equal to the turntable diameter. EUTs can’t be larger than the quiet zone.
  5. For compliance, variations in the quiet zone performance cannot exceed +/-4db for NSA and 6dB for sVSWR.
  6. Verification for IEC 61000-4-3 is a field uniformity test. Typically, a 1.5m x 1.5m vertical plane consisting of 16 points spaced 0.5 m apart is the measured area. At least 12 Points must vary by <6dB.
  1. MIL STD and DO-160 chambers can be Semi-Anechoic or Fully Anechoic. Standards require the absorber have a minimum absorption of 6dB from 80MHz to 250MHz and 10dB above 250Mhz. A table with a conductive top is bonded to the shield ground is used for testing the EUT.
  2. CISPR 25 chambers are fully lined on walls and ceiling, contain a similar table with metal lining on top, and must pass the Long Wire Test or the Reference Site Method test to meet the Standard.
  3. Reverb chambers rely upon the reflectivity of the walls and an internal movable paddle to reflect generated signals and increase the value of V/m generated from the transmit antenna.
  4. Information needed to design a reverb chamber is the lowest frequency, the test volume, maximum V/m, and standard to be tested to (MIL STD, DO, ISO).
These tips are presented by
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ESD
Simulators
The Importance of Checking the Calibration of ESD Simulators
A

more thorough “in-between calibration cycle” check of the ESD simulator’s output waveform is something every EMC engineer and technician should consider.

Why is this check important?
In a busy EMC test facility, the ESD simulator (a.k.a. “ESD gun” or guns if there is more than just one at the lab) can get damaged by inadvertent dropping that goes unreported or the switching mechanism can stop working. The gun may still produce a “zap” or make a noise as if it were still outputting the correct waveform, when in fact it is not. Because of these issues, a calibration check should be utilized frequently in between regular calibration cycles in order to be sure the waveform produced by the simulator is still within the requirements of the standard.
Note: IEC 61000-4-2 is one standard that describes the output waveform characteristics of the ESD gun, details of which are described later in this article.
Filters
An Alternative Approach to Specifying an EMI Filter
I

n previous articles (references 1 and 2), we covered the basics of EMI filters and some of the common reasons why they often fail to provide the insertion loss performance we expect from them.

We learned that the most common reason why filters fail, (besides bad coupling paths and cable routing around the filter, improper bonding and grounding, and non-ideal placement within the equipment) is that EMI filters are, more often than not, specified using 50Ω termination impedances on both the line and load sides during the insertion loss measurement.

The 50Ω/50Ω filter insertion loss measurement method is easy to perform because most RF measurement apparatus (connectors, cables, receivers, etc.) are built around a characteristic impedance of 50Ω. However, we know that filter performance is highly dependent on termination impedance and that real-life circuits rarely contain such ideal 50Ω impedances. Therefore, the 50Ω insertion loss test method cannot be relied upon to accurately predict filter performance once installed in actual equipment.

Tips for Selecting
Filters
  1. Filters should perform in both symmetric and asymmetric mode. That is, they should remove differential and common-mode noise. Some manufacturers offer comparatively smaller filters, but only specify asymmetric performance. These fail to remove differential noise.
  2. Filters should be rated for the appropriate maximum Line-to-Ground or Line-to-Line voltage for a 3 phase system. This eliminates the uncertainty of whether a filter will work at circuit voltages lower than the maximum filter rating.
  3. Filters should be rated for the appropriate circuit current and be able to withstand an overload of 140% for at least 15 minutes. This ensures the survival of the filter under overload conditions.
  4. Filters should be rated for low temperature rise in order to increase their durability and reliability.
  5. Power filters should be listed by a Nationally Recognized Testing Laboratory (e.g. UL, Intertek). This ensures that a 3rd party has approved the safety of the filters.
  1. When testing for avionics at 400Hz power, filters should also use Power Factor Correction Coils. This ensures that high reactive currents at 400Hz are neutralized.
  2. Larger power filters (above 200 Amps) should have an option to be floor standing. This ensures that most of the weight is on the stand rather than on the shielded wall.
  3. Protection performance for HEMP/EMP filters should be according to MIL-STD-188-125 or IEC 61000-4-24. These are the preeminent standards used today for specifying conducted Point of Entry protection.
  4. When protecting a facility against HEMP/EMP, it is crucial to indicate if the filters will be installed inside or outside the protective shield. Only one side of the filter has the protective elements;the protection side must be that which is exposed to the threat.
  5. When using electronic power sources connected to filters, the source should have a transformer in its output circuitry. This minimizes unwanted interaction with filters.
These tips are presented by
ETS Lindgren logo
Shielding
How EMC Shielding is Defeated
T

his article assumes the reader already has a basic understanding of how electromagnetic compatibility (EMC) shielding works. If you would like a refresher on EMC shielding, please see references 1 and 2, which describe how EMC shielding works in basic terms.

If you’re an electrical engineer and consider proper EMC shielding a mechanical only issue, please reconsider your position and keep reading.

Proper EMC shielding is both an electrical and mechanical design issue. Thoughtful coordination between the two disciplines is key to successful EMC shielding implementation on most product development projects.
Spectrum
Analyzers
EMI Measurement Receiver Requirements (CISPR 16-1-1)
I

f you’re performing commercial radiated and conducted emissions measurements strictly by the book, you will want to utilize a measurement receiver or spectrum analyzer that fully complies with CISPR 16-1-1. Briefly, this is what this means:

Note 1: The specifications in CISPR 16-1-1 apply to EMI receivers and spectrum analyzers. The term “measuring receiver” is also used in the EMC community and refers to both EMI receivers and spectrum analyzers.

Note 2: Often, the receiver specification under question depends on the frequency range of operation. In CISPR 16-1-1, there is one receiver specification covering the frequency range 9 kHz to 150 kHz (Band A), one covering 150 kHz to 30 MHz (Band B), one covering 30 MHz to 300 MHz (Band C), and finally one covering 300 MHz to 1,000 MHz (Band D). This article covers the 9 kHz to 1 GHz frequency range of operation and Bands A through D. Band E covers the 1 to 18 GHz frequency range of operation and has its own unique requirements.

Note 3: Specific requirements for measuring receivers used for military testing are found in MIL‑STD-461G and DEF STAN 59-411.

Test
Laboratories
The Value of Pre-compliance Testing
F

or some manufacturers, the cost of outfitting an entire full-compliance EMC test facility is not justified. These entities do not have enough sales volume, build unique one-off units, have tight margins, or lack the resources to staff an entire on-site, full-compliance test facility.

These types of manufacturers must rely heavily on the services of out-of-house, third-party test laboratories to properly test their products to confirm compliance before placing their devices on the market. The major problem with this approach, however, is that should the product fail at the test lab, the result will be delayed product shipments and missed revenue opportunities.

Utilizing early-stage in-house pre-compliance testing and sound engineering judgment, along with pre-compliance test data will boost confidence that the product will pass when it is eventually sent out-of-house for full compliance certification work. Learning in-house, using pre-compliance test methods as early as possible (when first prototypes are available), instead of at the end of the product development program (when attempting certification tests at the full-compliance test facility) will inevitably save manufacturers time and money. During final certification testing, there is immense pressure to meet your production release deadlines and being charged big dollars for lab time by the hour adds a whole other layer to that pressure. Having a product fail at this point in the process could be fatal to the project, especially if competitors get their product to market ahead of yours.

product marketplace
AK-40G Antenna Kit 20 Hz- 40 GHz
AK-40G Antenna Kit 20 Hz- 40 GHz
A.H. Systems’ AK-40G Portable antenna kit offers the best frequency range and performance in one case. This is the antenna kit you need for everyday testing. Just grab it and go. Inside the case is all the reliable antennas, current probes, and cables needed to satisfy a wide array of customer requirements. The antenna kit also comes with a tripod with azimuth and elevation head for antenna positioning and a tripod carrying case. Excellent performance, compact size and a lightweight package make this kit a preferred choice for field-testing and can ship with next-day, on-time delivery. Other antenna kits available.
Low-Frequency Immunity/Emissions Systems DC-400MHz
Low-Frequency Immunity/Emissions Systems DC-400MHz
Absolute EMC offers automated immunity systems for conducted immunity and magnetic immunity, covering many different standards for automotive, military, aircraft, and commercial requirements. IEC 61000-4-6/-8/-16/-19, IEC 55103-1/-2, ISO 11452-4/8, SAE J1113-2/-22, MIL: CE101/CS101/CS109/CS114/RE101/RS101, and DO-160: Sec19(CI/mag)/Sec21(BCI). Including a full complement of accessories for all needs. Contact Absolute EMC for more information.
RF Power Amplifiers 10kHz – 40GHz
RF Power Amplifiers 10kHz – 40GHz
Advanced Amplifiers provides a comprehensive selection of solid-state RF power amplifiers, offering continuous wave and pulse amplifiers with a variety of frequencies and power. These high energy efficient amplifiers, with simple front panel operation and rack mounting design, are tailored to meet EMC test standards covering a frequency range from 10kHz to 40GHz, up to 200V/m. EMC testing just became easier with these accurate and reliable instruments. Get more information at http://www.advancedamplifiers.com.
World Class Equipment at Low Prices
World Class Equipment at Low Prices
When equipment is built to last, someone else’s trade-in becomes your new find!

The AR Bargain Corner offers high-quality trade-ins, demos and discontinued models, many with the warranties still included. Shop now!
http://www.arworld.us/bargain-corner

IPX1 / IPX2 Drip Box System on display
IPX1 / IPX2 Drip Box System
Products intended for outdoor environments, or wet environments, often require Ingress Protection (IP) Code testing. ED&D’s cutting-edge solution for the IPX1 and IPX2 tests is the DBX Series Drip Box Test Systems. ED&D also invented IP Code Turntables, including a mini-turntable (shown) that allows for meeting requirements of the IP Code. ED&D also offers the device mounted in a chamber or it can be offered in combination with the Spray Test Chamber (STC-DBX Series). Other products for the IP Code include Dust Chambers, Spray Test Chambers, Spray Nozzles, Jet Nozzles, Accessibility Probes, and Oscillating Spray Testers.
ETS-Lindgren Announces New Fast-5™ Calibration Program
ETS-Lindgren Announces New Fast-5™ Calibration Program
Demonstrating its commitment to customer service, ETS-Lindgren announced its new Fast-5 Calibration Program. ETS-Lindgren will calibrate and return the customer’s device within five business days of receipt at its headquarters located in Cedar Park, Texas. This program includes standard calibration of all brands of antennas and probes, current clamps, LISNs, AMNs, and Health and Safety probes. There is no additional fee for this service.
Exodus, Your Solution for EMC!
Exodus, Your Solution for EMC!
Exodus Advanced Communications provides the best solutions for 10kHz-51GHz serving commercial and government entities worldwide. Exodus SSPA’s provide unprecedented reliability & performance and simplify EMC testing with the latest features for user-availability. Exodus provides the widest range of stand-alone modules, integrated amplifier chassis configurations, and full turn-key systems as needed for specific applications. Learn more http://www.exoduscomm.com.
Fair-Rite 75 Material Clamp-on Snap-Its Fight Low Frequency Noise
Fair-Rite 75 Material Clamp-on Snap-Its Fight Low Frequency Noise
  • Very effective at frequencies below 30MHz
  • Highly polished edges produce results comparable to a solid core
  • Available in a wide variety of sizes to fit most signal carrying cables

Fair-Rite Products designs and manufactures ferrite cores in many sizes and shapes in order to achieve EM compliance at frequencies from 100KHz to 1GHz. Call us today!

All New Multifunction Generator displayed
All New Multifunction Generator
Conducted immunity testers according to IEC standards (IEC 61000-4-x) up to 8kV Surges and 7kV EFT/Burst pulses. Ready for Surge, EFT/Burst, Ringwave, 10/700, Common Mode testing, Differential Mode Testing, Dips, Variations, Interrupts and more. Wide range of accessories (3 Phase CDN’s, Data Line CDN’s, Magnetic Field, ANSI coupling, etc). Modular architecture enables customized configuration. Powerful TEMA3000 automation software. Contact HV TECHNOLOGIES for more information.
The most EMI/EMC chambers in north america
Undisputed Leader in EMI/EMC Testing
With 28 labs in North America, NTS owns the most EMI/EMC chambers on the continent. With the world’s top EMI/EMC experts, NTS customers get immediate access to thought leaders who contribute to the development of industry standards for EMI/EMC testing. In fact, the experts at NTS are intellectuals who sit on advisory boards, create testing standards, and author reference material. Visit http://www.nts.com or call (844) 332-1885—and discover what it means to operate at a higher standard.
RAYMOND EMC by QuietDoortm
RAYMOND EMC QuietDoortm
The QuietDoortm line of shielded doors are proven to be easy to operate, reliable and long lasting. QuietDoortmRCM includes revolutionary innovations such as forward-mounted fingerstock, safe and secure latching hardware and easily serviced components. Single leaf models have a fully reversible swing which can be changed on site with no modifications to the door. A programmable logic control combined with the reliability of pneumatics can be added to create the most advanced shielded door automation system on the market. ADA compliant and other thresholds are available. Additional customized solutions are available.
Ultrafast Measurements EMI test receiver
Ultrafast Measurements
The R&S®ESW EMI test receiver offers outstanding performance, including high dynamic range and measurement accuracy. It meets the most stringent requirements for certification measurements in line with CISPR, EN, MIL‑STD-461, DO‑160 and FCC. With its FFT-based time domain scan, it captures and weights disturbance spectra in virtually no time. It offers preselection with selectable high pass filters and notch filters for the ISM bands.
Shielding of Electromagnetic Waves – Theory and Practice
Groundbreaking NEW Book on EMI Shielding:
Shielding of Electromagnetic Waves – Theory and Practice

International Shielding Expert George Kunkel discovered a critical error: the accepted theory of electromagnetic shielding violates the basic laws of physics. This new book, the result of over 50 years of research, provides a more accurate, efficient way for design engineers to apply electromagnetic theory in the shielding of electrical and electronic equipment. Learn more at http://www.spira-emi.com.

3CTEST's testing solution
Automotive Conducted Transient Immunity Testing System
3CTEST’s testing solution for ISO/TS 7637-4:2020 (Pulse A & Pulse B) has the frequency range of 0.1 μHz to 35 MHz and open-circuit voltage range of 0.5 V to 30 V. The system comprises signal generators CST 1075D and LFS 300B and all necessary accessories such as Balun transformer, HV AMN, HV shielded case, HV shielded junction box, HV battery load, software etc. Automatic calibration and tests can be performed via PC software control, which greatly improves the expandability and efficiency of the system. Learn more at http://www.3c-test.com.
 DL series electronic dc load 150 and 500 VDC
Vitrek New DL Series Electronic DC Load
The DL Series supports the testing requirements for the latest generation of off-line power supplies, DC-DC converters & LED Drivers. A variety of power ratings and input voltages available to meet your specific application. For a FREE demonstration visit www.vitrek.com/incompliance.
supplier resource guide
Supplier
Resource Guide
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Learn more about this month’s advertising supporters and their product offerings.
Advertiser Index
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A.H. Systems, Inc. – Ad 1, Ad 2, Ad 3
Advanced Test Equipment Rentals – Ad 1, Ad 2
AR – Ad 1, Ad 2
E. D. & D., Inc. – Ad 1, Ad 2
ETS-Lingdren – Ad 1, Ad 2
Exodus Advanced Communications – Ad 1, Ad 2
Fair-Rite Products Corp. – Ad 1, Ad 2
HV TECHNOLOGIES, Inc. – Ad 1, Ad 2
NTS – Ad 1, Ad 2
Raymond EMC – Ad 1, Ad 2
Rohde & Schwarz USA – Ad 1, Ad 2
Spira Manufacturing Corporation – Ad 1, Ad 2
Suzhou 3ctest Electronic Co. Ltd. Ad 1, Ad 2
Vitrek Corporation – Ad 1, Ad 2
Upcoming Events
October 5-8
MIL-STD-810G: Understanding, Planning and Performing Climatic and Dynamic Testing

October 6-7
Advanced PCB Design for EMC & SI

October 6-8
ETS-University: Automotive Course

October 12-14
ESD Auditor Certification Course

October 15
SCIP Database Solution

October 20-21
ETS-University: TILE! Software

October 27-29
Applying Practical EMI Design & Troubleshooting Techniques

November 2-5
Antenna Measurement Techniques Association (AMTA) 2020

November 9-12
MIL-STD-810G: Understanding, Planning and Performing Climatic and Dynamic Testing

November 10
Ground Resistance Training Seminar

November 10-12
EMC Fundamentals

November 16-17
IEEE SPCE 2020

November 16-18
Advanced PCB Design for EMC & SI and Mechanical Design for EMC

November 16-18
Sensors Expo & Conference

In Compliance: The Compliance information Resource for Electrical Engineers logo
Thanks for reading our October 2020 issue!