Will UWB change the world of headphones by delivering wireless Hi-Res audio?
There are many ways to define High Resolution, but in this case it is generally defined as 24-bit word depth and 96kHz sampling frequency (or higher) without using any compression techniques i.e. Linear PCM. The data rate required for 24/96 is 4.6Mbit/s.
To put this into context, CD quality i.e. 16/44.1 requires 1.411Mbit/s and Bluetooth (on a good day) can achieve around 700kBit/s. This gap creates the need for digital audio data compression which by definition is no longer Hi Res.
But is there an alternative? Turns out there is and there is a good chance it's already incorporated into your phone.
Closing the gap with UWB
UWB can offer the ~5Mbit/s required for Linear PCM Hi Res music: it’s low power and can achieve a significantly higher bit-rate than Bluetooth. And the remarkable thing is that many phones are already using UWB: iPhones 11 through to 14, Pixels 7 Pro and 8 Pro, and a host of Galaxy's.
However, to date, the usage of UWB in these phones has been limited to accurate location finding. UWB happens to also be very good at timing how long signals take to get places, thereby giving accurate distances between devices - something Bluetooth isn't able to do.
Why has UWB not been considered for headphones before?
The answer to this question is down to the twin issues of body blocking (or body shadowing) and detuning. Body blocking is a major problem for all wireless wearables. It occurs when the human body blocks the wireless transmission path causing the signal to drop out as the radio waves created by existing antennas are reflected or absorbed by the human body.
Detuning is what happens when an antenna with a physical form factor designed for operation in free space is detuned to a lower frequency when brought into close proximity to human tissues.
Both of these issues will result in drop out - and unreliable headphones.
Current solutions (and their drawbacks)
Body blocking and detuning aren't problems exclusive to UWB . They are issues common to the other bands also, whether sub-gigahertz, 2.4GHz (Bluetooth), 5GHz (Wi-Fi) or 6.5GHz (UWB). And whilst it's true that other factors can also block wireless frequencies, in the case of headphone use, it’s the body-blocking effect that has scuppered UWB as a useful frequency upgrade.
Admittedly, there are ways to solve the problem - such as boosting power or increasing buffer size. However, these options will result in battery drain, increased BOM costs or will not lend themselves to real-time applications.
Enter AntennaWare - and a new age for wireless headphones
AntennaWare originates from Queen’s University Belfast and is the result of many years of research by Dr. Matt Magill and Dr. Gareth Conway. The company spun out in 2020 and is establishing itself as a provider of innovative, novel and patented antenna design which will directly address the detrimental effects of body blocking.
Initially the founders focused on medical and automotive use, however, with results of up to 20dB of improved RF performance for body-worn applications the potential for use in the audio industry is clear. Particularly for real-time applications and digital wireless microphones where glitching is the singularly worse sin that can be committed
AntennaWare's BodyWave™ product is the only antenna specifically designed for wearables, counteracting the issues of body blocking and detuning. This new antenna makes it possible for UWB to be implemented in headphones, achieving a higher bit-rate, and so being able to deliver true high-res wireless audio. Presto - a potential new age for audiophile wireless headphone.
Aside from BodyWave for UWB and solving wireless music applications, AntennaWare is also providing solutions for DECT (1.9GHz) and Bluetooth (2.4GHz). The applications are myriad and include wearable IOT, medical, automotive and AR/VR.