What are the FCC and ETSI regulatory requirements for millimeter wave radar sensors?
mmWave Radar Regulations
Regulatory compliance is a non-negotiable requirement for any commercial radar product. The regulations balance the need for radar functionality with the protection of other spectrum users.
- Performance verification: confirm specifications against the application requirements before finalizing the design
- Environmental factors: temperature range, humidity, and vibration affect long-term reliability and parameter drift
- Cost vs. performance: evaluate whether the application demands premium components or standard commercial grades
- Interface compatibility: verify impedance, connector type, and mechanical form factor match the system architecture
- Margin allocation: include sufficient design margin to account for manufacturing tolerances and aging effects
Frequently Asked Questions
Do I need FCC certification for a prototype?
For internal R&D and development: the FCC allows operation of unregistered devices under the experimental radio service (FCC Part 5) or under the general exemption for R&D devices that are not marketed or sold. No FCC ID is required for prototypes used in the lab or at test facilities. However: if the prototype operates outdoors or could affect other spectrum users: an experimental license should be obtained (FCC Form 442, $80 application fee, 30-60 day processing). For trade shows and demonstrations: the FCC allows limited demonstration under Part 5 with a permit (STA: Special Temporary Authority). For any device that is sold, marketed, or imported for sale: full FCC certification (FCC ID) is required before the device can be legally operated.
How do regulations differ for occupant detection vs automotive radar?
In-cabin radar (occupant detection, gesture control): typically operates at 60 GHz (57-71 GHz) under FCC Part 15.255 / ETSI EN 302 567. Lower EIRP (+20 to +30 dBm) since the range is short (< 2 m). The key regulatory concern is RF exposure: the sensor is close to people (the occupants). The power density at the occupant nearest point must be < 1 W/m² (public exposure limit). This limits the maximum EIRP based on the sensor-to-occupant distance. Automotive exterior radar: operates at 77 GHz (76-81 GHz) under FCC Part 95 / ETSI EN 302 264. Higher EIRP (+40 to +55 dBm) for longer range. RF exposure: the radar is mounted behind the bumper/fascia. The nearest person is at least 20-30 cm away. At +50 dBm EIRP (100 W): power density at 30 cm = 100/(4π×0.09) = 88 W/m² (exceeds the occupational limit). However: the radar beam is typically narrow (5-10°), and the power density is lower at angles away from the beam peak. Compliance is demonstrated by calculating the power density at all accessible locations.
What about radar operation in tunnels or confined spaces?
In tunnels and confined spaces: the radar signal may reflect multiple times from walls and ceiling, creating multipath that appears as false targets. This is a sensor design challenge, not a regulatory issue. Regulatory: the same regulations apply in tunnels as in open air. The radar operates within its certified power limits. No additional certification is needed. Special consideration: some tunnels contain radiation-sensitive equipment (e.g., leaky feeder cables for radio communication, toll collection transponders). If there is a concern about interference: contact the tunnel operator and the relevant radio frequency coordination body.