Governance, EMC

[rahulrazdan][✓ rahulrazdan, 2025-06-16]

Figure 1

As discussed in previously, there is an intimate interaction between laws, regulations, and technology to build a governance framework which assigns liability and manages shared resources. In the case of the mechanical world, laws and regulations in transportation connect to traffic laws and the traffic infrastructure. With the development of wireless communications, sensing, and now wireless power, there is a need to build a governance structure for this space. In the US, the primary legal basis was the communication act passed in 1934 which created the regulator (Federal Communications Commission [FCC]). The FCC manages the radio spectrum (figure 1) through a range of regulatory and technical actions to ensure its efficient and interference-free use. It allocates specific frequency bands for various services—such as broadcasting, cellular, satellite, public safety, and amateur radio—based on national needs and international agreements. The FCC issues licenses to commercial and non-commercial users, setting terms for power limits, coverage areas, and operating conditions. It also conducts spectrum auctions to assign frequencies for commercial use, such as 5G, while reserving portions for public services and unlicensed uses like Wi-Fi. In addition, the FCC enforces rules to prevent harmful interference, coordinates spectrum sharing and repurposing efforts, and leads initiatives like dynamic spectrum access and band reallocation to adapt to evolving technological demands. To enforce these standards, the FCC requires many devices to undergo testing and certification before they can be marketed or sold in the United States. This process is carried out by FCC-recognized testing laboratories, known as accredited Conformity Assessment Bodies (CABs), which evaluate products against applicable Part 15 or Part 18 regulations, among others. Certified devices must meet limits on emissions, immunity, and specific absorption rate (SAR) when applicable. Once a product passes testing, the lab submits a report to a Telecommunications Certification Body (TCB), which issues the FCC ID and authorizes the product for sale. These labs play a critical role in ensuring compliance, supporting innovation while maintaining spectrum integrity and public safety.

FCC Part 15 and Part 18 differ primarily in the type and purpose of radio frequency (RF) emissions they regulate. Part 15 governs devices that intentionally or unintentionally emit RF energy for communication purposes, such as Wi-Fi routers, Bluetooth devices, and computers. These devices must not cause harmful interference and must accept interference from licensed users. In contrast, Part 18 regulates Industrial, Scientific, and Medical (ISM) equipment that emits RF energy not for communication, but for performing physical functions like heating, welding, or medical treatments—examples include microwave ovens and RF diathermy machines. While both parts limit electromagnetic interference, Part 15 devices operate under stricter emissions limits due to their proximity to communication bands, whereas Part 18 devices are allowed higher emissions in designated ISM frequency bands. Additionally, health and safety regulations for Part 18 equipment are typically overseen by other agencies such as the FDA or OSHA, while the FCC focuses on interference mitigation.

Figure 2

A key instrument for electromagnetic testing is an anechoic chamber (figure 2). An anechoic chamber is a specialized, sound- and radio wave-absorbing enclosure designed to create an environment free from reflections and external interference. Its walls, ceiling, and floor are typically lined with wedge-shaped foam or ferrite tiles that absorb electromagnetic or acoustic waves, depending on the application. For radio frequency (RF) testing, the chamber is constructed with conductive materials (like steel or copper) to form a Faraday cage, isolating it from external RF signals. In acoustic chambers, sound-absorbing foam eliminates echoes and simulates free-field conditions. Anechoic chambers are critical in industries such as telecommunications, defense, aerospace, and consumer electronics, where they are used to test antenna performance, electromagnetic compatibility (EMC), emissions compliance, radar systems, or audio equipment in highly controlled, repeatable conditions. The chamber ensures that test measurements reflect only the characteristics of the device under test (DUT), without environmental interference

What are the implications for automakers ?

In modern vehicles, electronics are no longer confined to infotainment or engine control—sensors, communication modules, and controllers are now central to vehicle safety and performance. These systems emit and receive electromagnetic energy, which can result in electromagnetic interference (EMI) if not properly managed. EMI can compromise safety-critical applications like radar-based adaptive cruise control or camera-based lane keeping. Sensor technologies introduce unique EMI challenges. Radar and lidar sensors, which are critical for driver assistance and autonomous systems, must not only avoid interference with each other but must also operate within spectrum allocations defined by the FCC and global bodies like the ITU. Similarly, cameras and ultrasonic sensors are susceptible to noise from nearby power electronics, especially in electric vehicles. EMI from poorly shielded cables or high-frequency switching components can cause data corruption, missed detections, or degraded signal integrity—raising both functional safety and regulatory concerns.

From a communications standpoint, FCC-compliant system design must also consider interoperability and coexistence. In a vehicle packed with Bluetooth, Wi-Fi, GPS, DSRC or C-V2X, and cellular modules, maintaining RF harmony requires careful frequency planning, shielding, and filtering. The FCC’s evolving rules for the 5.9 GHz band—reallocating portions from DSRC to C-V2X—illustrate how regulatory frameworks directly impact product architecture. OEMs must track these developments and validate that their communication modules not only operate within approved frequency bands but also do not emit spurious signals that could violate FCC emission ceilings.

To meet FCC standards while ensuring high system reliability, automotive developers must embed EMI considerations early in the design cycle. Pre-compliance testing, EMI-aware PCB layout, and component-level certification all contribute to a smoother path to regulatory approval. Moreover, aligning FCC requirements with international automotive EMC standards—like CISPR 25 and UNECE R10—helps ensure global market readiness. As vehicles grow increasingly software-defined, connected, and autonomous, managing EMI through smart engineering and regulatory foresight will be a critical enabler of innovation, safety, and compliance.

As discussed, FCC regulations are primarily focused on electromagnetic interference. However, if RF energy has the potential to cause health issues, other regulators are involved. Health and safety regulation for FCC Part 18 devices—such as microwave ovens and medical RF equipment—is primarily handled by agencies. The Food and Drug Administration (FDA) oversees radiation-emitting electronic products to ensure they meet safety standards for human exposure, particularly for consumer appliances and medical devices. The Occupational Safety and Health Administration (OSHA) establishes workplace safety limits for RF exposure to protect employees who operate or work near such equipment. Meanwhile, the National Institute for Occupational Safety and Health (NIOSH) conducts research and provides guidance on safe RF exposure levels in occupational settings. While the FCC regulates RF emissions from Part 18 devices to prevent interference with licensed communication systems, it relies on these other agencies to ensure that the devices do not pose health risks to users or workers.

In the case of vehicle makers, part 18 health issues manifest themselves in use-models such as wireless power delivery where SAR levels may impact safety directly.

Figure 3

Finally, while the examples used above are from a US context, similar structures exist in all other geographies.