They go unnoticed in everyday life, but the electromagnetic waves They are everywhere and influence how our devices behave. From garage door openers to the electronics of a modern car, everything can be affected by interference if the equipment isn't properly designed and validated in controlled environments. That's where interference comes in. electromagnetic compatibility tests on the bench, which allow verification, with rigor and repeatability, of how they emit and how they withstand disturbances.
When we talk about bench testing, we mean reproducing, in the laboratory, real and regulatory conditions to verify the immunity and emission of a product. The dual objective is clear: on the one hand, to verify that the equipment functions normally when subjected to external electromagnetic stimuli (conducted and radiated immunity) and, on the other hand, to ensure that the disturbances it generates Emissions to the grid and the environment remain below the limits of applicable regulations (conducted and radiated emissions). This validation is key for market access and safety.
Editorial noteSome of the technical literature on this topic has been disseminated in recent years; as an example, an article from 2023-10-23 reached thousands of reads and consolidated interest in benchtop EMC testing within sectors such as automotive and consumer electronics.
What is EMC and why does it matter to a bank?
Electromagnetic compatibility (EMC) is the discipline that studies the unwanted generation, propagation and reception of electromagnetic energy. Two concepts underpin it: emission (what a device "releases" into the environment) and susceptibility or immunity (how vulnerable it is to external disturbances). In the test bench, both aspects are evaluated using methods, instrumentation, and controlled environments to obtain repeatable and comparable results.
In practical terms, the EMI radiated It is usually evaluated between 30 MHz and 10 GHz (the range commonly used in regulatory frameworks such as that of the FCC), while the EMI conducted The analysis ranges from several kHz to 30 MHz. These bands allow the detection of everything from switching noise and power line harmonics to high-frequency emissions that could disrupt nearby communications.
Types of benchtop EMC tests
The test batteries are organized around two main blocks: issue (what the team generates) and immunity (what it is capable of withstanding without failing). In a well-configured test bench, the corresponding test profiles are applied, with continuous monitoring of the product under test and of the injected field or voltage levels.
Emission tests
- Radiated emissions: verification of the radiated energy to the atmosphere created by the team.
- Conducted emissions: measurement of the noise that the product injects into the network electrical.
- Network harmonics: control of current harmonics generated by nonlinear loads.
- Flicker: evaluation of the fluctuation of tension and brightness caused by load variations.
- Radio disturbance power: a measure of disruptive energy broadcast on radio bands.
- “Clicks” or intermittent noise: event detection impulsive noise Of short duration.
Immunity assays
- Radiation immunity: exposure to electromagnetic fields to verify functional behavior.
- Driven immunity: injection of signals and perturbations directly into cables and ports.
- Magnetic fields at mains frequency: evaluation before 50 / 60 Hz and its effects on sensors and loops.
- Fast transients (EFT/Burst): simulation of switching bursts typical of industrial environments.
- Sudden increases (Surge): discharges of high energy due to lightning or network maneuvers.
- Voltage drops and dips: verifying behavior in response to dips and interrupts network.
- Electrostatic discharges (ESD): shocks from static charge in contact or through the air.
The ultimate purpose of these tests is twofold: to determine the functional response of the product against external disturbances and verify that its emissions are below the limits normative valid. Without that seal, selling equipment in regulated markets is simply not feasible.
EMC test benches for E-Drives in electric vehicles
Electric drives (E-Drives) are the heart of electric vehicles, and their EMC validation on a test bench is critical to ensure performance, safety and reliabilityUsing specific test benches, they are subjected to fields, injections, and operating scenarios that reproduce everything from acceleration and braking maneuvers to power transients.
A key focus is the susceptibilityThe system assesses which external fields or signals may affect the drive and whether the control, power, and associated electronics maintain uninterrupted service. Simultaneously, the following is measured: issue of the system (radiated and conducted) to ensure that it does not disturb other subsystems of the vehicle itself or the environment.
Regulatory compliance in the automotive industry is demanding, which is why EMC test benches for E-Drives are also used for verify compliance with manufacturer standards and specifications. Detecting vulnerabilities in the early stages reduces the risk of late redesign, avoids recalls, and improves performance. global reliability vehicle.
There are specialized providers offering state-of-the-art E-Drive test benches to accelerate validation and improve quality. These types of solutions, such as those offered by companies dedicated exclusively to EMC, aim to contribute equipment and methodology that give confidence to manufacturers and consumers in a market that is evolving at great speed.
Standards, measurement ranges and regulatory frameworks
In addition to the typical measurement ranges (30 MHz–10 GHz for radiated and kHz–30 MHz for conducted), bench tests are aligned with international regulations and local requirements. In Europe, the Electromagnetic Compatibility Directive 2014/30/EU and the RED framework for radio establish design and assessment obligations for a large part of electronic products.
Recognized organizations and laboratories act as Notified Body (NB) and can issue opinions or certifications that facilitate access to the EU market, and their work is often equally valid for markets such as the US, China, Japan, or Australia. In the United States, the FCC recognizes certain laboratories as CABs (Conformity Assessment Bodies), which means that Your results are accepted for sale in that country.
In more specific areas, the IEC 61000 family defines test methods and severity levels for emission and immunityAnd the military and aerospace world relies on standards such as MIL-STD-461 for radiated and conducted susceptibility, and MIL-STD-810 for environmental robustness (vibration, shocks, temperature). Alignment with these references is essential to ensure comparability and acceptance.
Within RF validation, the testing ecosystem includes trials of OTA (Over The Air) for antennas and connectivity, as well as the Specific Absorption Rate (SAR) when the device is used in close proximity to the body. These tests, while not purely EMC, complement the regulatory compliance map for radio equipment.
Automotive: why the road needs to enter the laboratory
A modern vehicle integrates countless electronic units: systems of active and passive safetyInfotainment, connectivity, driver assistance sensors, and automated driving systems must always function, even in the presence of intense disturbances. That's why EMC testing is mandatory and recurring, especially in the automotive industry.
With the arrival of electromobility, high-power inverters and batteries have raised the bar: generated fields The stresses on an electric powertrain can be much higher than those on internal combustion engines. Furthermore, the severity of the disturbances varies with speed, load, acceleration, and braking. All of this necessitates new, more realistic, and well-defined test profiles.
Onboard connectivity adds another layer: ultra-broadband access, 5GAutomotive radar, GNSS, and other radios coexist in the vehicle. EMC banks must ensure that emissions from the engine or other modules do not degrade these services, and that the overall immunity is sufficient to maintain them. critical functions.
Testing on real roads is expensive and difficult to repeat, so the industry is betting on simulate traffic and the electromagnetic environment in the laboratory. This requires cameras, antennas, couplers, generators, loads, and a repertoire of test cases capable of keeping pace with development. This need affects manufacturers, suppliers, laboratories, and inspection bodies.
There are EMC laboratory networks in Europe and the United States that also have specific recognitions from top-tier automotive brands (such as GM, JLR, Stellantis, Ford or Hyundai) to test under their own specificationsThis capillarity and accreditation accelerate time to market and facilitate the planning of global validations.
Technical case: Conical-Plate bench for HEMP environments
One particularly interesting line of academic work is the design of benches that replicate the environment of a electromagnetic pulse High-altitude electromagnetic fields (HEMP). Among the viable architectures, the Conical-Plate type guided wave bank stands out, capable of generating a defined and uniform field for moderately sized equipment.
In a university project, a Conical-Plate bench was proposed according to the most energetic profile of HEMP (E1), referencing IEC 61000-2-9 for the modeling and IEC 61000-4-25 in reduced-size test benches, along with the RS105 susceptibility test of MIL-STD-461. This aligns the bench conditions with widely accepted regulatory frameworks.
Two variants were developed: one with a superior conductive surface based on aluminum plate and another made of steel cables, maintaining the same dimensions in both cases: 480 cm × 250 cm × 157,5 cm (L × W × H). The objective was to compare field uniformity, efficiency, and reproducibility of the pulses in the work area.
The models were defined and analyzed using electromagnetic simulation tools (e.g., CST Studio Suite) to study propagation, reflections, and spatial distribution of the electric fieldThe validation included comparing the pulse parameters in the useful zone with the profiles of the selected standards.
Finally, 0,125 m³ cubes with different characteristics were introduced into the test area to evaluate how they altered the field generated and the shielding/insulation effect provided by different materials and geometries. This approach illustrates how a well-designed bench allows for the exploration of extreme scenarios and ensures robustness against severe EM threats.
Tangible benefits of good EMC validation
When a product surpasses its EMC battery, the first advantage is a reliable operationUnexplained field failures due to RFI are minimized, and "weird effects" when multiple devices are in use are avoided. This results in fewer incidents and a more robust user experience.
The second advantage is regulatory compliance. Many countries require equipment to demonstrate accordance with EMC standards; ignoring this can lead to market lockouts or legal issues. Successfully going through the bank simplifies marking, technical documentation, and access to multiple regions.
The third is the Product QualityTesting helps detect design problems, unforeseen coupling paths, or insufficient filtering and shielding early on, before they become expensive to correct. And, in turn, it strengthens reputation and... customer trust.
A practical example is the manufacturers of ruggedized tablets and Panel PCs that integrate advanced technologies of shielding and filteringwith thorough EMI/EMS testing to ensure operation in environments with high electromagnetic activity. Furthermore, many of these devices meet standards such as MIL-STD-810G or IP65, resisting shock, vibration, and water ingress without compromising performance.
Services, accreditations and market access
EMC and RF laboratories work with consumer, industrial, and other sectors. medical, automotive, military and aerospaceIn addition to ICT. Their services cover everything from preparing tests to issuing reports and certifications under local and international frameworks, and also include OTA and SAR tests when the product integrates radio.
Some centers act as Notified Body for Directive 2014/30/EU (EMC) and can issue opinions valid for RED where applicable. The FCC-recognized CAB status means that the reports it issues are accepted for the U.S. market. This combination of roles facilitates a path to compliance. overall for the manufacturer.
In the automotive sector, beyond horizontal standards, many OEMs publish particular specificationsHaving laboratories recognized by brands such as GM, JLR, Stellantis, Ford or Hyundai allows testing directly against these requirements, reducing friction and time in the approval of components and systems.
Good design and preparation practices for the bank
To arrive at the trial with guarantees, it is advisable to apply principles from the beginning of EMC by design: short return routes, continuous mass planes, well-selected filteringSeparation of analog/digital domains, effective shielding, and optimized case connectivity. This is how the bank confirms hypotheses rather than revealing surprises.
In preparing for tests, agree with the laboratory on the sample, the operation modeThe wiring configurations and acceptance criteria save time. It is also advisable to instrument the DUT to monitor key signals during immunity testing (e.g., communication frames or system states) and to be able to to diagnose any functional degradation.
It's advisable to plan iterations: a first pass of pre-compliance It allows for corrections and optimization before the formal campaign. In cases, small ferrite adjustmentsFilters, harness routing, or ground turrets make a difference in conducted/radiated emission and robustness against ESD, EFT, or surge.
Transparency and data protection in the relationship with the laboratory
In the processes of contracting and contacting laboratories, information is usually provided on aspects of Data ProtectionTypically, the data controller specifies that the purpose is to respond to the request, that the legal basis is consent, and that data is not transferred to third parties except legal obligationand that the rights of access, rectification, and erasure (among others) can be exercised, for example, through a dedicated channel such as LOPD@telproce.com. It also refers to the Privacy Policy where the information is expanded.
All of the above leads us to a clear idea: the electromagnetic compatibility test bench is the bridge between design and reality, the place where it is certified that a device coexists with its environment without disturbing or being disturbed; from specialized benches for E-Drives, through advanced architectures such as Conical-Plate for HEMP scenarios, to the complete battery of emission and immunity defined by IEC, MIL-STD and regulatory frameworks such as 2014/30/EU and FCC, supported by accredited laboratories, OTA/SAR when there is radio and OEM recognitions in automotive, everything adds up to achieve more reliable, compliant and appreciated products by users.
