What is the interference risk between automotive radar and 5G millimeter wave in shared spectrum?
Automotive Radar and 5G mmW Coexistence
As both automotive radar and 5G mmW deploy at massive scale (hundreds of millions of vehicles with radar, millions of 5G mmW cells), spectrum coexistence becomes increasingly important. Regulators and standards bodies are actively studying interference scenarios to establish coexistence rules before problems emerge at scale.
- 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
Frequently Asked Questions
Has interference between automotive radar and 5G been observed?
No significant interference has been observed in current deployments because the frequency bands are well-separated (radar at 76-81 GHz, 5G at 24-43 GHz). The concern is for future deployments when 5G/6G may expand into the 71-76 GHz band adjacent to automotive radar. The 24 GHz radar band does overlap with the 5G n258 band (24.25-27.5 GHz), which is why 24 GHz automotive radar is being phased out globally in favor of 77 GHz.
Can automotive radar interfere with other vehicles' radars?
Yes. As radar density increases (4-6 radars per vehicle, millions of vehicles), radar-to-radar interference is a growing concern. Some interference scenarios: a vehicle's radar receives chirp signals from an oncoming vehicle's radar, creating ghost targets or elevated noise floor. Current mitigation: CFAR processing adapts the detection threshold, and different vehicle manufacturers use slightly different chirp parameters that reduce interference. Future mitigation: standardized radar interference protocols, randomized chirp timing, and joint radar-communication waveforms.
What role does the FCC play in radar-5G coexistence?
The FCC regulates spectrum allocation in the US and sets emission limits and interference protection criteria. For the 76-81 GHz radar band, the FCC (Part 95) sets maximum radiated power limits for radar. For mmW 5G, the FCC (Part 30) sets emission limits and out-of-band emission masks. When new spectrum allocations are proposed (e.g., 71-76 GHz for communications), the FCC conducts interference studies and public comment proceedings to establish coexistence rules before authorizing use.