What are the main challenges involved with mmWave 5G?
Looking at this from both a technical and commercial perspective, there are three big problems when it comes to 5G using mmWave frequencies.
Firstly; signal penetration. mmWave is easily blocked; buildings, poor weather, even a user’s hand can block a signal. This makes offering mmWave 5G, particularly in dense urban areas where we see the greatest number of potential use cases tricky.
Next, the limited range of mmWave. These frequencies only have a range of around 300 meters, that is a staggering 50x less than 4G. The result is that significantly more equipment is needed to deliver consistent reliable coverage.
Finally, with a greater volume of equipment, comes the need for significantly higher infrastructure investment. The implications of this are compounded as mmWave must use advanced technologies such as beam-steering for effective coverage which come with a much higher price tag.
Despite these challenges, the reality is that, unlike lower bands, mmWave 5G is able to offer speeds 8x faster than 4G. This is essential to realise the promises of 5G and makes these problems well worth solving and to do this, operators will have to embrace innovation and new approaches.
How can these issues be overcome when looking at commercial rollouts?
The industry has seen numerous solutions developed to address these issues but more often than not, it creates another problem for operators – cost. The catch for operators has so far been that equipment such as Electronically Steerable Antennas (ESA) that can be used to amplify and improve 5G coverage in dense urban areas, is typically too high cost to be a realistic option. The cost of deploying these solutions in the volumes needed to overcome the limitations of mmWave would make it incredibly difficult to see the return on investment needed for 5G to be deemed a commercial success.
The key here is not just finding a solution that can address the challenges, but one that is developed to deliver when it comes to return on investment. One of the most promising technologies developed with this principle in mind, uses Liquid Crystal to build Smart Antennas.
What is Liquid Crystal technology and how does it work when it comes to beam steering?
Based on research from Technical University of Darmstadt, Liquid Crystal (LC) has been used to build phased array smart antennas. These can take the form of relay antennas, Customer Premises Equipment, or can even integrate into vehicles to realise the connected cars vision; but let’s first look at how the technology works.
Using Liquid Crystal as the core material of the phased array enables the beam-steering that is essential for mmWave 5G at a fraction of the cost. These smart antennas combine liquid crystal display LC display technology with microwave LCs and array antenna design. Unlike most beam-steering options on the market, this is a totally passive design which has several key benefits when it comes to cost reduction. The materials used are cost effective and can be mass produced, reducing the CAPEX. Not only this but its nature as a passive solution uses very low power, reducing the ongoing OPEX costs of the solution. The result is a technology that can be deployed at scale to ensure 5G rollouts deliver swiftly on investment and supports the high-speed, high-capacity, low latency connectivity promised by 5G.
What are the potential applications for liquid crystal phased array antennas?
Liquid Crystal not only delivers on the technology side, but its versatile form factor means there are a huge number of applications for these smart antennas. From Relay antennas for operators to CPE equipment the technology can be used to fit a wide range of applications.
Beyond this, there is an opportunity to install this technology to enable connected cars. Liquid Crystal based antennas can be integrated into car roofs, plus, given that mmWave works in similar frequency bands to satellite means we can make this a hybrid satellite/5G antenna, so where 5G isn’t available, the systems can use a satellite failover.
What will the technology mean for 5G and even 6G deployments?
Beyond the problems liquid crystal smart antennas solve for 5G, the solutions have additional benefits when we look further into the future. Most technologies that are being developed are being stretched to their physical limitations to work in mmWave frequencies, however a quirk of using Liquid Crystal as the core material for ESAs is performance improves in higher frequencies. This makes it not only a viable solution to 5G stumbling blocks, but it has the potential to thrive in a 6G world.
Ultimately, the operators that embrace these principles and look at innovative ways to overcome the challenges surrounding their infrastructure investments will be the ones that are able to deliver exactly what their customers are waiting for, and will see the swiftest and greatest returns on the 5G networks and beyond.
Dr Onur Karabey is CEO at ALCAN Systems and developed the original technology that underpins ALCAN’s smart antenna while doing his PhD at TU Darmstadt. With over 10 years of experience as a microwave engineer, most of those focused on liquid crystal based smart antennas, he brings a wealth of applicable real-world experience to the ALCAN leadership team. He holds a Ph.D. from TU Darmstadt, where he was recognized as Outstanding Researcher, and has received 5 awards, including Ideenwettbewerb New Idea Competition in 2011, the Springer Thesis – the “best of the best” award in 2013, VDE‐ITG Literature Prize, the Leopold B. Felsen Award for Excellence in Electromagnetics, and 3rd place in the European Satellite Navigation Competition (ESNC).