A world without mmWave?: No 4G, 5G and beyond
Author : Dan Rhodes, Filtronic
26 September 2024
Dan Rhodes, Business Development Director at designer and manufacturer of RF-to-mmWave components and subsystems, Filtronic, explores how the absence of mmWave technologies would impact key advancements, not only in daily life but across essential sectors too.
Without high-frequency mmWave Radio Frequency (RF) technology, the modern world would be dramatically different. This change would reverberate across various sectors, shaping a world devoid of essential technologies that we often take for granted.
The use of high-frequency RF in our modern digital world is essential today, and will become even more central in the future. It expands the data capacity that we consume, and satisfies our voracious appetite for more. Without the essential components and subsystems of the mmWave spectrum, the technologies of the future would stay the stuff of science fiction.
Thankfully, mmWave technology is helping to expand possibilities, and push performance boundaries ever higher. mmWave refers to radio frequencies in the electromagnetic spectrum ranging from 30GHz to 300GHz, further characterised by their short wavelengths – one to ten millimetres – allowing them to carry large amounts of data.
Without it, network capacity would be significantly limited, affecting our ability to use data-intensive applications, things we take for granted today. Think crowded areas, where many people are accessing services like video streaming, as we move into an era of even higher data consumption and connectivity demands.
Industry limitations
The processing power and computing capabilities driving the networks are dependent on high-frequency connections provided by mmWave technology. If these connections are not available, data transfer becomes slower due to narrower data pipes, impacting not only which architecture can be configured but also what can be achieved on the networks for business and commercial use.
For instance, in satellite communications, mmWave technology is essential for deploying large networks, particularly in low-Earth orbit. These networks rely on high frequencies to establish substantial data links, known as feeder or gateway links, between satellites and ground stations.
The bandwidth would be insufficient if only lower microwave frequencies were used, leading to limited speed and capacity. In short, this would hinder the ability to provide high-speed internet to users in remote locations.
Meanwhile, the telecommunications sector also requires mmWave for areas where fibre optic cables are either not available or too expensive to deploy. Fibre can’t always be laid, for example across rivers, motorways, mountainous regions or in densely-populated urban areas, without significant disruption. In such cases, wireless links between base stations and the core network are necessary, especially when implementing 5G services.
For radar systems in defence, higher frequencies are needed to detect and track small objects accurately, as well as establishing secure communication channels with narrow beams that are difficult to detect.
Similarly, missile seekers use high frequencies to lock onto targets with precision, relying on directed mmWave beams to reduce detection and interception chances. In these applications, the absence of mmWave would limit the effectiveness of military systems, making it a crucial component in defence.
Requirements for future advancements
It’s not just in sector-specific applications that higher frequencies are needed. To support advancements in fields like AI, autonomous vehicles and the Internet of Things (IoT), mmWave is used, for instance, in sensors for gesture control systems. These rely on higher frequencies to detect motion with precision over both long and short distances.
Plus, secure private networks benefit from such technology too, because these applications demand low latency and high-frequency options to operate effectively. Companies like Filtronic actively work on integrating mmWave technology to meet these requirements.
In fact, a significant development in Filtronic’s mmWave technology involves the use of high-power, solid-state amplifiers (SSPAs). Traditionally, the compound semiconductor gallium arsenide (GaAs) has been used within mmWave SSPAs, due to its long history and established performance. However, even at higher frequencies, such as those above 40GHz, gallium nitride (GaN) is now becoming more prevalent.
GaN offers better power density and efficiency, allowing for more power output from the same surface area, not only to help in making devices more compact, but also in extending the range of signal transmission.
This move comes as the goals for the next phase of 5G and future 6G include achieving wireless XHaul data rates of 100 gigabits per second. Currently, the highest capacity XHaul links operate at around 25 gigabits per second.
To reach 100 gigabits per second, multiple mmWave channels are needed, where we will likely see the aggregation of different frequency bands, such as E-band, W-band, D-band and beyond, to achieve the required bandwidth.
Achieving these goals is challenging and requires meticulous management of manufacturing processes, as well as vertical integration of design, manufacturing and testing.
Technology is becoming more complex, and industries are increasingly dependent on data, so it’s essential to maintain reliability as well as performance when we move towards higher frequencies for applications that we might just take for granted.
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