Ultra-wideband (UWB) is a short-range wireless communication technology that uses very wide frequency channels – typically 500 MHz wide – to enable secure, low-power communication. Its standout feature is fine ranging: the ability to precisely measure the distance between two devices by calculating signal travel time.

In automotive applications, UWB has become an essential technology, especially for enabling secure digital keys and passive entry systems. As UWB adoption in vehicles increases, challenges such as spectrum congestion and interference are becoming more pronounced.

UWB operates outside the normal rules of licensed and unlicensed spectrum under FCC Part 15, and shares airwaves with other wireless technologies, including Wi-Fi in the 6-GHz band. This makes it susceptible to signal interference as UWB adoption grows across automotive and Wi-Fi-dependent consumer devices.

The potential for signal congestion is driving a move to harmonize UWB channels to accommodate more devices, reduce interference and future-proof new deployments. Unusually, the effort is being led by carmakers and Tier 1 suppliers, with the typically slower-moving automotive sector setting the pace for phone vendors and other consumer electronics manufacturers.

Channel Expansion Frequencies

Although the IEEE 802.15.4 standard defines 16 UWB channels, regulatory and other restrictions effectively limit all UWB traffic to one channel (channel 9), which operates in the 8-GHz frequency band. Channel 9 is globally available and free from interference with other common technologies. But as deployments scale, relying on a single channel limits performance, increases the likelihood of device interference and impedes widescale UWB adoption.

To alleviate this, the industry is investigating a move to harmonize UWB support across additional channels, specifically channels 10 (~8.4 GHz) and 12 (~9 GHz). These offer wide global availability, relatively clean spectrum and are expected to dominate future expansion efforts. Other channels, including 13 through 15, have also been defined but are considered less suitable for low-power UWB technology due to effects such as increased path loss, which can degrade signal strength. 

What UWB Channel Expansion Means for the Automotive Sector

For automakers and Tier 1 suppliers, access to additional channels would support greater redundancy and flexibility in safety applications. The most prominent of these is digital car keys, where UWB is used to securely access the vehicle. UWB’s fine ranging capability – accurate to within centimeters – helps prevent relay attacks by verifying that a key fob or smartphone is physically close to the vehicle.

Other automotive uses accelerating the need for additional UWB channels include:

• Child presence detection, seatbelt reminders and automatic trunk access, all of which rely on UWB-based radar to detect and locate objects and people.
• Autonomous charging alignment, which guides robotaxis and other electric vehicles to precisely dock with charging stations.
• Battery management systems, where UWB can replace bulky wire harnesses by transmitting data, such as charge state and temperature, between battery cells. 

Testing Requirements for UWB in Automotive

As the automotive industry increases its reliance on UWB, test complexity is increasing. Unlike many consumer devices that rely on pass/fail or “go/no-go” tests, automotive systems demand more rigorous examination – particularly at the RF physical layer.

Parametric testing is essential to ensure UWB devices meet quality, reliability and regulatory standards over their lifecycle – from R&D and validation to high-volume production. This includes metrics such as:

• Signal quality across multiple frequencies.
• Timing precision for fine ranging and radar use cases.
• Robustness in multi-device and multi-channel environments.

As production volumes grow, multi-device test efficiency becomes critical. Test solutions must balance cost and throughput while maintaining tight tolerances, enabling OEMs to handle millions of devices per year and still meet the automotive sector’s quality standards.

The testing approach also depends on which integration model is being used. For instance, if a Tier 1 supplier integrates silicon from a chipset vendor with their own front-end and other components, additional testing may be required at the module or system level. In contrast, the use of fully integrated modules, which may only require the addition of an antenna, can reduce the test burden but still necessitates thorough verification during vehicle assembly.

With UWB in a state of flux, there’s also a need to future-proof test equipment. LitePoint’s systems already support all UWB channels to 10.6 GHz.

UWB Is Becoming a Fixture in Automotive Applications

UWB has already proven itself as a vital automotive technology thanks to its excellent security, precise location and measurement capabilities, and low power consumption. As the number of applications grows, channel expansion is both necessary and inevitable to maintain performance, minimize interference with other UWB and Wi-Fi devices, and enable deployments to meet anticipated demand.

For automotive OEMs and Tier 1 suppliers, this means not only preparing for more channels but establishing comprehensive test protocols capable of handling increasingly complex system integration. Getting this right will ensure UWB continues to enable secure, intelligent and feature-rich vehicles in the years ahead.