Understanding and mitigating emissions are essential to creating reliable, compliant electronics. In this blog post, we will introduce the two primary types of emissions and offer practical steps for troubleshooting both conducted and radiated EMC issues.

Understanding Conducted vs. Radiated Emissions

EMC emissions are broadly categorized into two types: conducted and radiated. Conducted emissions are noise currents traveling out of the product back onto the AC mains cable. These emissions can interfere with other equipment connected to the same power source. Typically, the frequencies of concern for this noise range from 150 kHz to 30 MHz. Radiated emissions, on the other hand, are electromagnetic fields that radiate through the air from the product and can interfere with nearby electronics. Typically, the frequencies of concern for this noise range from 30 to 6000 MHz.

Troubleshooting Conducted Emissions

When addressing conducted emissions, the first step is identifying the source within the device. Common culprits include switching power supplies, motor drivers, and high-speed digital circuits. Using a Line Impedance Stabilization Network (LISN) in conjunction with a spectrum analyzer can help isolate the frequency bands causing failures.

Once the frequencies are identified, the next step is to locate the physical origin. A current probe can be used to measure emissions on individual cables to pinpoint noisy lines. Mitigation often involves improving PCB layout—such as minimizing loop areas and ensuring solid return paths—and implementing filtering techniques. Installing differential-mode and common-mode filters at power entry points can significantly reduce emissions. In some cases, re-routing cables or adding ferrite beads may also help.

Troubleshooting Radiated Emissions

Radiated emissions are often more challenging to troubleshoot. Initial testing is typically performed on the complete device under test (DUT) to verify compliance with emissions standards.

If the DUT fails, diagnostic tools such as near-field probes paired with a spectrum analyzer become invaluable for identifying hot spots on the PCB. Focus should be placed on areas with high-speed digital signals, clock lines, and power converters, as these are frequent sources of unwanted radiation.

Shielding is a common solution, but it should be a last resort after addressing fundamental design issues. Improving grounding and ensuring low-impedance paths can reduce emissions at the source. Additionally, managing cable routing to prevent unintentional antennas and using properly terminated signal lines can reduce unwanted radiation. Antenna-like structures, such as long traces or unterminated cables, should be minimized or shielded effectively.

Digital clocks are often a major source of high-frequency radiated emissions; techniques such as improving clock distribution and using spread spectrum clocking can help mitigate these emissions.

An engineer at Accola works with electronics at a test bench

How to Catch Issues Early

By systematically approaching conducted and radiated emissions—starting with measurement, followed by localization and mitigation—a skilled engineer an resolve EMC issues efficiently.

Catching EMC issues early in the design process is key to ensuring both compliance and product reliability. Start by integrating EMC requirements into the design brief, considering relevant standards and potential interference sources. Early use of electromagnetic simulation tools can help predict how your product will behave in its electromagnetic environment, allowing you to adjust designs before physical prototypes are made.

After developing the first prototype, you should perform pre-compliance EMC testing to measure both radiated and conducted emissions. This helps identify major issues early on. Near-field scanning can then pinpoint high-frequency emission sources, allowing for targeted design modifications. Basic mitigation techniques like decoupling capacitors, shielding, and grounding can be applied to prototypes to address issues immediately.

Now, iterative testing is essential… you need to retest with each design revision to ensure that these mitigation strategies work. Use tools like spectrum analyzers and oscilloscopes for real-time feedback. Before finalizing the design, schedule pre-compliance testing at a specialized facility to catch any remaining issues.

Then, once the product is finished, we’ll conduct system-level EMI/EMC certification testing to verify that it does not interfere with other devices in the final product.

For a comprehensive, hands-on guide to EMC troubleshooting, including detailed procedures, equipment setup, and results analysis, I recommend Workbench Troubleshooting EMC Emissions (Volume 2) by Kenneth Wyatt. Drawing on over 30 years of experience at Hewlett-Packard and Agilent Technologies, Wyatt provides clear explanations, real-world examples, and expert tips that are especially valuable for engineers working in design and compliance testing.

Bring Your Project to Accola

If you’re in need of expert assistance in developing or manufacturing medical devices, drug delivery systems, or combination products, Accola is a trusted engineering and manufacturing partner for innovators in the MedTech industry. We help innovators in MedTech bring safe, reliable devices to market by developing and testing products to rigorous medical device standards like IEC 60601. From electrical safety and EMC testing to mechanical, thermal, and performance verification, our team ensures your devices meet regulatory requirements and perform as intended.

To minimize risks and reduce costly delays, we rigorously test products in the early stages of development. We identify and address potential EMC-related issues before they become problems. This proactive approach ensures your product complies with regulatory standards and performs optimally.

With our expertise, you can confidently navigate the challenges of product development and bring your innovations to market. Trust us with your next complex electromechanical project.

About the Author

Noam Sheetrit is an Electrical Engineer at Accola, where he contributes to the design, verification, and compliance of electromechanical systems for medical devices. He holds a Master’s degree in Electrical Engineering and a Bachelor’s in Biomedical Engineering, enabling him to develop integrated systems that prioritize patient safety and usability. His expertise spans circuit design, schematic capture, and system integration, ensuring that devices meet quality standards such as IEC 60601 and IEC 61010.

The post Don’t Fail Your EMC Testing: How to Troubleshoot Emissions Early appeared first on Accola.

Almost 4 years ago, I chose to pursue a graduate degree while working a full-time job to grow in my career and to increase the depth and breadth of my technical knowledge. The journey was demanding but it imparted valuable lessons that can broadly apply to any situation where one must balance their day-to-day responsibilities with the effort necessary to grow and develop in a career.

Based on my experience, here are five key lessons that have been most valuable in balancing graduate school with a full-time engineering job:

Communicate Transparently and Often

First is the importance of clear and frequent communication. Whether it is with your manager, colleagues, professors, or classmates, setting expectations and keeping others informed of your availability, workload, and deadlines is essential. Transparency builds trust and can often to lead to support structures that enable your success. A professor allowing an extension of a project presentation deadline because they know you will be traveling for business the same week, a manager encouraging flexible work hours during exam week, and classmates willing to start a group project earlier are all examples of support that was offered to me as a direct result of open communication.

Set Realistic Expectations

Setting expectations with others is just as important as setting realistic expectations for yourself. Taking on more without readjusting what is already on your plate is a tried-and-true recipe for burnout.  One way I learned to avoid this was to write down every reoccurring responsibility/commitment that I had now (include work, school, social, and general life-maintenance), my desired results in an ideal world, and the minimum necessary. Then I removed any items that don’t have that minimum necessity and ranked the priority of the remaining items. This activity can lead to a collection of minor changes that add up to significant impact. For example, it led me to stop folding my t-shirts after doing laundry, lower my expectations for how long a workout needs to be, and start saying no to additional responsibilities when their priority did not rank higher than anything on my list.

Find Synergy

Another powerful strategy is to try and find synergy between work and school where possible. This involved conversations with coworkers to learn whether their projects touched on my course material and conversations with professors to find additional resources that more closely aligned with my career. Not only did this help save time, but it also made my coursework more valuable and helped solidify the material I was learning. I once did a mathematical analysis of a switch mode power supply I was designing into a product to align with a course I was taking, even though this level of analysis was not needed for the design. It helped me understand the formulas I was learning in the course and months later when I needed to troubleshoot issues in a prototype, the in-depth understanding I had of the component allowed me to isolate problems quickly.

Time Management Strategy

Lastly and perhaps most importantly, having a defined strategy for time management is critical. There is no one-size-fits-all approach to this but just as gaps in your own approach tend to be obvious and quickly apparent, so do the right techniques. Personally, I found success in Trello and the pomodoro technique. Trello is one of many available tools that allow you to create cards for individual tasks, sort these cards into lists, rank priorities, and track progress. My personal Trello board had lists titled Backlog, This Week, Today, In Progress, Awaiting Input, and Complete. The pomodoro technique is a method by which you spend 25 minutes of pure focus on a task, followed by a 5-minute break. After four of these sessions or “pomodoros”, the break becomes a 15-minute break. Short breaks are used to reflect on what was accomplished in the last session and what is planned for the next. This technique helped me stay focused and helped me understand how long tasks were taking me.

Find a Company that Cares

Balancing a full-time career with graduate studies is not just about making it out with a degree—it’s about growing as a professional.

A key part of my journey in completing my graduate degree was working at a company that values professional development and growth in their employees.

Accola provides an environment that made balancing hands-on project work with finishing my degree both possible and rewarding. Accola’s culture builds people up through challenging projects, promoting continuous learning and skill development. It makes bright engineers even better equipped to take on complex design work.

Having completed my Master of Science in Electrical Engineering at NC State, I feel that I’m better equipped to design and develop medical devices that change the lives of patients everywhere.

About the Author

Noam Sheetrit is an Electrical Engineer at Accola, where he contributes to the design, verification, and compliance of electromechanical systems for medical devices. He holds a Master’s degree in Electrical Engineering and a Bachelor’s in Biomedical Engineering, enabling him to develop integrated systems that prioritize patient safety and usability. His expertise spans circuit design, schematic capture, and system integration, ensuring that devices meet quality standards such as IEC 60601 and IEC 61010.

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