All electrical installations or devices affect one another when interconnected or operated close to one another. For example, you may have observed interference between television sets, radios, or GSM handsets. How do you manage that interference? This is where electromagnetic compatibility (EMC) steps in, as it helps to keep all those side effects under reasonable control.
Electromagnetic compatibility encompasses all the existing and potential methods and technologies for decreasing disruption and increasing insusceptibility. Let’s take a closer look at what exactly electromagnetic compatibility is and why it’s important.
What is Electromagnetic Compatibility?
Electromagnetic compatibility is described as the capability of devices and systems to work in their electromagnetic environment without negatively affecting their own operations or creating errors. It also ensures that the functioning of a device doesn’t impact the electromagnetic environment to the extent that the operations of other systems and devices are impaired.
The main objective of implementing EMC measures is to guarantee that a range of different electrical devices and equipment can function nearby without producing any unwarranted interference that affects performance (known as Electromagnetic Interference or EMI). Therefore, manufacturers apply EMC practices to reduce this interference in order to ensure that various electrical devices and equipment are compatible and can operate in the presence of one another.
The Fundamentals of Electromagnetic Compatibility
The concept of electromagnetic compatibility involves two main elements:
• EMI Emissions - They refer to the generation of undesirable electromagnetic energy that must be decreased below certain acceptable limits to avoid causing any disruption to other devices.
• Susceptibility and Immunity - The susceptibility of an electronic device defines how it reacts to undesirable electromagnetic energy. The purpose of an electrical circuit design is to guarantee an adequately high level of immunity to these undesirable signals.
How Electromagnetism Works
Before we dive deeper into how electromagnetic compatibility works and its possible applications, it’s important to discuss the basic concept of electromagnetism.
Electromagnetism is generated when an electrical current passes along a simple conductor, for instance, a long wire or a piece of conductive material wrapped around a metal base. As current flows through the whole of the conductor, it generates a magnetic field around it, which has a definite direction. This direction of current flowing through the conductor determines the “North” and “South” poles produced.
Therefore, it is essential to establish a relationship between current passing along the conductor and the resulting magnetic field created around it by this flow of current. We define this relationship between Electricity and Magnetism in the form of Electromagnetism.
Main Industries that Use Electromagnetism
The following are some of the main industries that leverage the concept of electromagnetism.
Automotive
The motors, generators, and magnetic levitation used in trains all use the concept of electromagnetism. Along with using electromagnetic force to allow a train to levitate over a track, electromagnets are also used to accelerate trains at high speeds.
Telecommunications & Broadcasting
Telecommunication systems like radio, phone, and TV use electromagnetic waves to convey information through the air. Many telecom equipment rooms use EMC technology to avoid interference from devices that may cause serious equipment failures.
Entertainment
Electromagnets are extensively used in loudspeakers, earphones, electric bells, and magnetic recording and data storage equipment, such as tape recorders. The entertainment industry also uses electromagnets to create devices and components, like hard drives and VCRs.
Medical & Scientific
Electromagnets are often found in scientific and medical equipment, including magnetic resonance imaging (MRI) machines in hospitals and scientific tools like nuclear magnetic resonance (NMR) spectrometers, particle accelerators, and mass spectrometers.
What are EMC Shields?
EMC best practices ensure that a circuit has been designed in such a way that it prevents disruption by shielding.
An EMC shield is a device that contains, reflects, or absorbs a radiated electrical signal. It is used to protect a sensitive signal from exterior electromagnetic signals, or to avoid a stronger signal from leaking out and interfering with nearby electronics.
For instance, you can cover printed circuit board (PCB) elements such as integrated circuits (IC) chips and active components, or cables and connectors between PCBs with EMC shielding.
Key Products that Use Electromagnetic Capability
Almost all electronic devices and products make use of EMC to ensure that their own operations as well as those of other devices around them are not impaired. However, there are certain legal regulations and directives that explain what products are covered.
Center for Devices and Radiological Health (CDRH)
As part of the FDA, the Center for Devices and Radiological Health (CDRH) examines EMI associated with medical equipment, not only from the technical viewpoint but also from the view of public health problems and solutions.
CDRH performs extensive lab testing to detect devices that might be susceptible to complications caused by EMI. Moreover, it also investigates occurrences of device EMI, and works on solutions (such as the one related to cardiac pacemakers).
Electromagnetic Compatibility (EMC) Directive
The EMC Directive covers most electronic products sold in the EU region, such as LED lighting, kitchen appliances, electric bikes, and more. The objective is to restrict EMI from electronic devices, preventing them from interfering with other equipment. For instance, LED displays and other electronic equipment can interfere with radio communication in the vicinity.
Furthermore, the EMC Directive also makes Conformitè Europëenne (CE) marking mandatory for all products that it covers. This marking specifies that a device has been evaluated by the manufacturer and considered to meet EU health, safety, and environmental protection requirements.
Why is Electromagnetic Compatibility Important?
Over the past few years, we’ve seen several reported incidents where, due to the lack of electromagnetic compatibility and EMC testing, companies had to recall or withdraw products from the market. We’ve also seen some famous brands being left humiliated due to their products that failed to comply with EMC and RF regulations.
Therefore, EMC testing is a crucial part of a product’s design journey. As EMC certification has become an indispensable obstacle to pass before your product reaches the market, it is critical that you get this element of your design right. However, it’s important that you perform EMC testing early on in a product’s design lifecycle. This way, you can avoid the risk of project delays and cost overruns just before your intended launch.
How to Ensure Electromagnetic Compatibility
Every country has specific EMC requirements that each product needs to pass before being launched in the market. As electromagnetic compatibility is an intangible phenomenon, it is challenging for manufacturers to know if their devices or equipment are electromagnetically compatible.
The only way to practically find out is to perform rigorous scientific EMC tests. For testing, you will need a production model, and you may also have to repeat the test at a later date to make sure that compliance is maintained after changes in the production. For instance, OEM parts and accessories have to be checked for compatibility with the projected use of the final product.
Difference between EMI and EMC
As discussed, EMI is electromagnetic interference and EMC is electromagnetic capability. You may think of EMI as one portion of EMC, and they are both significant aspects that must be considered when dealing with electronic products.
• EMI is an electronic emission that interferes with components, RF systems, and most electronic devices. It can be the result of manmade or natural occurrences.
• EMC is the term used to describe how well a device or system can work in an electromagnetic environment.
Simply put, the key difference between EMI and EMC is that EMI is the terminology for radiation and EMC simply is the capability of a product to operate within the presence of radiation.
How Laird’s EMC Components Are Different
Laird offers complete and reliable solutions to customers, including thermal interface materials (TIMs), EMC components, and EMI shielding, so that they can reduce the total cost of ownership and launch new products quickly.
Our biggest differentiator is our material capabilities that most of our competitors lack. Laird Performance Materials is a global leader in high-performance TIMs and TIM-automated application solutions that protect your electronic devices from overheating. Our inductive components filter out noises produced by active components to preserve the integrity of system signals. Moreover, our electromagnetic products diminish disruptive waste energy by means of enclosure solutions and absorbers.
We understand that customers need quick solutions and responses so that they can launch their products quickly. Therefore, Laird provides them with the solutions needed as quickly as possible. Many manufacturers leave EMC as one of the last parts of a design, which further intensifies the need for a quicker response.
Laird’s Industry-Leading EMC Solutions
Laird offers a variety of technologies in the electromagnetic domain that reduces stray EMI radiations. Some of the key solutions are:
Microwave Absorbers
mm-Wave and microwave absorbers in several configurations decrease the adverse influence of radiated signals. Our microwave and mm-wave absorbers include low-loss dielectric materials like filled polymers, but you can also find them as custom-molded thermoplastic and elastomeric, reticulated foam, as well as liquids, textiles, and custom composite items.
• Custom magnetic absorbers and ruggedized specialty microwave absorbers are ideal to be used in tough conditions in any environment.
• Microwave absorber gap fillers reduce noise interference while opening a thermal path.
• Films and elastomers resolve issues of internal cavity resonance up to the mm range and offer good overall protection from low to high frequencies.
• Hybrid absorbers in interface configurations sort out compliance problems at minimum deflection force.
Enclosure Solutions
Fabric-over-Foam (FOF) Gaskets
These offer softer shielding for computers, telecom, or other applications where it’s critical to have shielding attenuation and high conductivity. As an enclosure solution, these gaskets are a popular choice for applications that need low compression force but also require high conductivity and shielding attenuation.
Fingerstock Metal Gaskets
We are specialists in the design of a large number of miniature thin strip metal parts and also offer a wide collection of enclosure shielding gaskets. You can access over 400 standard Laird fingerstock metal gaskets for shielding and grounding.
Standard Surface Mount Board Level Shields
You can find our standard surface mount shields in one-piece and two-piece designs. The former design offers EMI protection on six sides, whereas the latter allows checkup or repair of shielded modules like IC packages without the risk of damaging the PCB by taking out the whole shield or incurring any tooling overheads.
Comparatively, it is easier and quicker to repair the components in the two-piece shield design and it also decreases board rework. However, no tooling overheads are associated with both types of standard designs.
Form-in-Place (FIP) Elastomers/ Electrically Conductive Elastomers
Our electrically conductive elastomers stop EMI and are suitable for use in changing operating temperatures, weather conditions, and varying levels of corrosion and chemical exposure. The FIP elastomers are compatible with plastic, metal, and plated substrates, whereas electrically conductive elastomers offer environmental sealing for additional protection.
Not sure which electromagnetic solution is right for you? You’re not alone! Most of the customers don’t clearly know what solution they want. So we take the time to fully understand our customer needs and then present solutions. Our integrated solutions resolve numerous electromagnetic and heat dissipation problems together with structural issues through a single design. To learn more about how we can help you ensure EMC, please get in touch.