Automotive EMC compliance testing

Your automotive EMC testing challenges

There are three fundamental challenges for automotive EMC compliance:

• Ensuring compliance with relevant standards
• Efficient use of test resources
• Keeping the test process on time and on budget

Overcoming automotive EMC compliance challenges

Autonomous driving means more sensitive sensors. Higher levels of ADAS and autonomous driving introduce:

• Proliferation of more sensitive sensors such as 4D imaging radar
• Increased use of interference vulnerable sensors, e.g., cameras
• Lower failure tolerance for safety-critical systems
• Increased data rates and higher order modulation of digital in-vehicle networks

EMC robustness must increase to ensure system reliability in real-world scenarios.

Electrification means high-voltage, fast-switching semiconductors. Electrified powertrains (HV inverters, onboard chargers and motors) use fast-switching SiC/GaN devices that generate:

• Steep dv/dt edges
• Radiated emissions at higher harmonics
• New immunity concerns for other vehicle electronics
• Increased emissions dependent upon the vehicle’s operational state (voltage, power, torque, temperature, switching modulation)

Rohde & Schwarz guides OEMs and component suppliers on how these changes impact EMC design and testing.

Connectivity means new features and services enabled by increased use of wireless technologies. High expectations of availability and quality for infotainment, safety and convenience services create:

• High density of wireless technologies, often with overlapping frequency bands
• Increased frequency range (Wi-Fi, UWB, 5G, NTN)
• Increased volume of tests for checking the quality of services under all relevant operating conditions
• Larger and more sensitive high-resolution display screens

Rohde & Schwarz uses its test instruments and vast knowledge of wireless technologies to optimize test processes and accommodate demanding immunity requirements.

Advanced automotive EMC test techniques

EMC testing under dynamic driving conditions

Emissions vary with speed, acceleration and load, especially when it comes to electric vehicles. Therefore, a new methodology is required to account for:

• Fast switching of currents with high gradients at high clock frequencies
• Sensitive ADAS sensors in close proximity to high voltage components
• Evolving ISO, CISPR, UN ECE R10 and OEM-specific standards

Together with system partners, Rohde & Schwarz enables dynamic EMC test scenarios with the R&S®ELEKTRA test automation software and a complete test platform.

Reverberation chamber testing

Reverberation chambers are gaining relevance in automotive immunity testing due to:

• High field uniformity that provides more realistic stress test from all aspect angles
• Efficient high field strength generation capability
• Suitability for large DUTs (battery packs, inverters, HV components) without a turntable

Rohde & Schwarz provides you with early guidance - even before formal standard adoption. Together with selected partners, we enable you to maximize the advantages of reverberation chambers for your EMC measurements.

Navigate the automotive EMC standards landscape

Rohde & Schwarz participates in key automotive EMC standards bodies and integrates upcoming requirements into test solutions. As such, our instruments, software and systems are always aligned with current and upcoming requirements, enabling you to focus on gaining EMC compliance as efficiently as possible.

Automotive EMI emissions standards

CISPR 12 – protection of off-board receivers

• Radiated emission 30 MHz to 1000 MHz, protection distance 10 m
• Used for regulatory purposes (referenced in legally binding UN ECE R10) and CE certification for devices
• To be published in Europe as EN 55012:202x

CISPR 25 – protection of on-board receivers

• To be published in Europe on national level only, e.g., BS EN 55025 (UK) and DIN EN 55025 (Germany
• EN 55025 is not listed in the Official Journal of the EU and has no legal status. Therefore, the car component manufacturer has to apply the specific standards of the OEM.

CISPR 36 – protection of off-board receivers

• Electric and hybrid road vehicles
• Quasi-peak limits for radiated emission (magnetic field) 150 kHz to 30 MHz, similar to CISPR 11 Class B Group 2
• Measurement with 60 cm loop antenna in radial (x) and transverse (y) direction at four positions, center of loop at fixed height of 1.30 m, measurement distance of 3 m
• Measurements with electric engine running only, constant speed 40 km/h ± 20 % drive

ISO 11451 – immunity testing for electrical disturbances from narrowband radiated electromagnetic energy

• Testing at complete vehicle level
• Radiated immunity frequency range, from 10 kHz to 18 GHz

ISO 11452 – immunity testing of automotive electrical components to narrowband radiated electromagnetic energy

• Component level testing
• Radiated immunity range of 200 MHz to 18 GHz

UN ECE R10 – type approval of vehicles and their components

• Defines the control of unwanted electromagnetic emissions and ensures immunity to external or internal disturbances
• Mandatory for market access in the European Economic Area (EEA) and recognized by over 50 countries globally

OEM-specific requirements (VW, BMW, MB, Stellantis, Geely, etc.)

• Often based on existing CISPR and ISO standards with stricter limits