Understanding Ultra-Wideband and Where To Use It

You’re probably familiar with UWB as the location technology made famous by consumer devices such as Apple AirTags. But this technology is broadly applicable as a solution to MANY problems – and in many industries as well.

Published on September 6, 2023

Understanding Ultra-Wideband and Where To Use It

The Road to Ubiquity: The Smartphone-Native Edge of UWB

Two years ago when Apple introduced the AirTag, a small coin-sized tag that could help users locate anything the tag is attached to via a smartphone location app, the execution was flawless. It’s no exaggeration to say that it looked something like a magic trick: just open your phone and follow the arrow on the screen directly to the object you’re looking for, down to centimeter-level precision. Many other location systems are able, at best, to get you in the same room as the target device. But to have location so precise and updated multiple times a second made AirTags the product to beat.

How did they achieve this? Via the use of ultra-wideband, a very old wireless technology with a very new set of use cases. Ultra-wideband has been in use for over 150 years, but was largely limited to use in naval communications, radar communications, collision avoidance in vehicles, ground scanning, and more.

Importantly, while Apple paved the way for integrating UWB technology into their mobile devices, others have also followed suit. Many other high-end smartphone manufacturers have begun integrating UWB radios into their flagship models, including the Google Pixel 6 and 7, the Samsung Galazy Note 20 and S21, S22, and S23, as well as the Galazy Z Fold 2, 3, 4, and 5. The inclusion of UWB in the latest phones from Apple, Google, and Samsung is something of a massive greenlight for those interested in developing UWB applications – integration with these three manufacturers is essentially ubiquity among the most popular mobile devices, a status that once propelled Bluetooth to become indispensable as well. This means millions of UWB devices are in the field right now, ready to be utilized -- and with that, applications in industries beyond commercial have begun to follow.

Defining Characteristics

One of the defining features of UWB is simply found in its name: the frequency range of these signals occupies a very wide spectral band that is multiple gigahertz across. The FCC’s designation for ultra-wideband in the early 2000s designated UWB to function between 3.1 to 10.6 GHz, a whopping 7.5 GHz of bandwidth where channels are over 500MHz wide. By contrast, all of 2.4 GHz Wi-Fi operates within an ~80 MHz bandwidth. Ultra-wideband, it seems, is a fitting name.

Interestingly enough, this wide band of signal is the result of another one of UWB’s defining features: extremely short pulse durations. In radio physics, shorter pulses result in waves with wider spectrum, and in Ultra-Wideband those pulses are less than a nanosecond each. The pulses also are performed with extremely low power usage, which is one of the features of UWB that makes it uniquely non-destructive and noninterfering with collocated wireless technologies.

UWB’s spectral density sits extremely low by comparison to technologies like GPS, Bluetooth, and Wi-Fi, orders of magnitude less than these. To understand this, remember those 500 MHz channels. A nanosecond pulse across a 500 MHz range occupies, in total, much less of that frequency over the allotted time than a 2.4GHz Wi-Fi signal might occupy over one 20MHz- or 40MHz-wide channel.

Let’s look at this another way, using bread as a metaphor (who doesn’t love bread?). If you picture wireless spectrum as a blank canvas in the form of a piece of toast, you can think of wireless density in terms of how much butter we apply to that toast, and where. UWB is operating with less butter over the surface of more bread, where competing technologies might be a whole pat of butter that only occupies a square inch or so. UWB does its work without even becoming recognizable, let alone destructive, to those smaller areas allocated to other technologies in the same general space.

How Do We Use It?

As previously mentioned, UWB has a long and storied history in the form of pulse radio, long-range naval communications, radar, and other more recent implementations. But one of the results of an increased adoption rate of UWB in the smartphone market is that more applications become possible that previously required dedicated hardware. In typical indoor positioning scenarios, UWB functions on the basis of anchors and tags: anchors, which serve as a point of reference for a fixed location in an environment, and tags, which move around the environment and have their location determined by the anchor infrastructure.

The defining characteristic of UWB radios is the ability to perform accurate distance measurement between just two points of reference. Location of tags can be calculated by anchors and is aided by multiple antennas. These are oriented across different axes to help determine not just signal strength but relative angle from the anchor to a tag. The resulting sub-5cm accuracy makes UWB particularly accurate for pinpoint location, much more accurate than is possible with most other wireless technologies. Applications for precise location sensing in industrial or medical environments are everywhere.

In crowded and densely populated medical environments which already contain a large amount of Wi-Fi and Bluetooth traffic, UWB is an ideal solution to track mobile medical equipment. Administrators can track down to the precise spot in a room where medical equipment is located, or can track patient progress through rooms and treatments with a wearable tag.

The same applies to industrial environments, where similar concerns apply: lots of devices on the go, with a need for traceability. Warehouse robots, which are highly mobile throughout a facility, can be tracked with a much higher degree of accuracy via UWB. That means better operational awareness, more precise monitoring, and better decision-making and task routing in the system overall. Forklifts, mobile equipment, and more can be precisely monitored to assign work to the nearest operator.

It’s not just asset tracking either: this precise monitoring can also be used to help autonomous robots avoid collisions, or to stay strictly within the safe boundaries via a mapped geofencing system. The total combination of all sensors on a device in addition to a precise sense of its location is a recipe for much more efficient automation and a more complete image of what’s happening in and around a device. UWB, in conjunction with many incumbent technologies and sensors, furthers the promise of IoT – location, sense and control so precise that a true digital twin can be constructed for a fleet of devices.

Just Announced: Our Sera™ NX040 Series

The first of our portfolio of UWB-based modules, our Sera NX04 Series, introduces a novel hardware offering and software / development tools to bring UWB to a new range of applications. Based on the NXP Trimension™ SR040 UWB chipset and the Nordic Semiconductor nRF52833 Bluetooth LE / NFC chipset, the Sera NX040 is an exceptional path forward for OEMs looking to integrate UWB on top of existing Bluetooth / NFC applications.

We offer multiple development options to help manufacturers speed their design to market, including rapid firmware app development with a Python-based scripting engine, support for the nRF Connect SDK, AT Command Set for hosted designs, ranging toolkit with sample applications, and a mobile app for configuration and data visualization.

Laird Connectivity is an experienced partner in wireless design with the expertise and support to help you develop your ideal product and get it to market on time and on budget. For more on our Sera NX040 Series, please visit the Sera NX040 product page: