To satisfy our ever-increasing need for greater network capacity, we’re seeing a growing number of antennas in the world around us. This will result in undesirable effects on our environmental landscape, such as unsightly installations on buildings or antennas taking up space inside our homes…or will it?
Looking back at urban infrastructure development during the second half of the 20th century, we’ve been left with an ugly legacy of clutter – from TV aerials, satellite dishes, electric cabling to the pipes and paraphernalia of water utility. But it shouldn’t have to be that way.
We should also consider the concerns and perceptions people have about wireless technology today. Many already have a negative perception of ubiquitous connectivity infrastructure, or they are worried about radiation causing harm. So, what can we do to reduce apprehension towards new technology as we expand 5G based networks?
CHASM and CC create innovative 5G antenna solution
5G will require more antennas closer to the point of use to enable high-speed connectivity for users. The use of transparent structures will help us overcome some of the concerns expressed by many people by ‘hiding in plain sight’ on buildings, ceilings, light fixtures or in windows. Alongside our client CHASM™ Advanced Materials, Cambridge Consultants has delivered an innovative antenna solution using transparent conductive materials for advanced radio frequency (RF) applications. The implications of this breakthrough are powerful, ushering in a future where far fewer antennas clutter our environment.
Together with CHASM, CC began working on characterising the RF properties of the AgeNT™ materials and investigated the possibility of manufacturing transparent antennas using it. Our overarching goal was to deliver innovative technology using the material while significantly reducing the cycle time, from design to manufacturing, by using predictive tools and optimised manufacturing processes.
In early 2023, CC presented a successful proof of concept (PoC) see-through 5G antenna suitable for phased array applications using the CHASM AgeNT™ material – along with a roadmap to make the material and design methodology available to industry. The development has huge implications for the commercial viability of unobtrusive antenna structures and opens the doors for countless novel applications.
Historically, there have been very few transparent solutions available, and they have been limited to very specific and expensive niche applications. Our process streamlines the simulation, design and testing of the transparent antenna. Together with the low-cost manufacturing process used by CHASM, this development enables shorter time to market, as well as the use of transparent antennas in mass-market products.
Transparent antenna design
The focus of the initial project was to optimise the conductivity and RF properties of the transparent AgeNT™ material at particular frequencies. The material itself is made up of a metal mesh covered by a layer of carbon nanotubes to provide additional conductivity and improved RF properties.
To enable accurate design and simulation of an antenna, it is crucial the properties of the materials used in the simulation are accurate. To this end, we worked on a series of measurements to characterise AgeNT™ material versus frequency, allowing us to build a model of the material to be used in the simulation tools for the design of the antenna.
Utilising the measurement results of the AgeNT™ material allowed us to simulate and optimise the design of a patch antenna operating at 3.5GHz (5G band n78). Using the transparent process provided by CHASM the PoC antenna was produced. We then measured the performance using our in-house advanced Antenna Research Centre (ARC) to assess full 3D characterisation of the antenna performance.
After designing a tuneable dual-layer patch antenna with impressive results and good alignment between simulation and measurement, we successfully achieved performance similar to a standard Printed Circuit Board (PCB) based patch antenna.
Beamforming for transparent phased array antennas
A crucial element of successful deployment of transparent phased array antennas is the support for beamforming. Beamforming unlocks many of the benefits of 5G. Focusing the wireless signal in a particular direction provides a better signal-to-noise ratio (SNR), enabling higher data rates and fewer retransmissions.
A phased array is made up of a number of individual antenna elements where the amplitude and phase can be controlled, individually, to allow beamforming and beam steering.
We are currently in the process of developing a 2×2 MIMO phased antenna array for 5G using an improved version of the PoC patch antenna developed together with CHASM as part of the previous phase of the project.
Potential clear antenna market applications
This development has helped pave the way towards this novel area of commercial development for CHASM, offering many potential market applications of transparent phased array antennas. From the routers for wireless to the home (WTH) and small cell antenna systems that we are currently developing; to back-haul, smart city hotspots and autonomous vehicles applications, we are excited to see transparent panels that include antenna systems, as well as other circuitry, in the near future.
Here are just a few examples of where transparent antennas could be game changing that we’re now exploring:
- If 5G is used to deliver broadband to the home, then the number of antennas required to maximise performance, thus user experience, will be higher. The current solution of using large ‘pizza box’ antenna panels fitted to the outside wall of the building comes with a set of issues, including antennas on the outside of buildings being unsightly, potentially requiring landlord consent and occasionally not being allowed at all on a Grade I or II listed building. Meanwhile, the installation of the antenna needs to be completed by a professional installer adding cost to the end user. Here, transparent antennas would be less intrusive, offering greater customer experience without the drawbacks of current solutions.
- If satellite communication is to become ubiquitous in autonomous vehicles, to guarantee seamless roaming from terrestrial networks to low earth orbit (LEO) or geostationary orbit (GEO) satellites, then high-gain beam steerable antennas will be required. Current solutions consist of a large antenna panel fitted on the roof of the vehicle, requiring additional installation time and cost. If we could instead integrate the antenna into the windscreens, mirrors and windows – which are ideal places to locate transparent antennas – it will reduce equipment and installation costs.
- There is also scope to explore wide bandwidth, or multi band antenna solutions supporting beamforming. The increased connectivity offered by broadband LEO services could be leveraged for larger, better performing antenna arrays.
I for one am immensely excited by the prospect of an approach that allows antenna manufacturers to streamline simulation, design cycles and testing while opening the market to a new generation of antenna technology that promises to declutter buildings and our lives. Drop me an email to discuss the huge potential of transparent antennas in more detail, and we’ll keep you updated on how this project continues to progress.
Expert authors
With over two decades in RF and electronics design, Johan Skatt is a Senior Consultant in RF and Antennas at CC. Since joining CC in 2017, Johan has led RF engineering on a range on industrial, commercial and defence and security projects, including high-reliability radio system and antenna design for smart metering, aerospace and defence applications.
