The RF spectrum is not infinite
Ensuring RF spectrum sustainability amidst soaring demand
In the ever-evolving landscape of technology and industry, one finite resource remains the unsung hero in enabling our modern way of life – the radio frequency (RF) spectrum. Here Tudor Williams, director of technology at Filtronic, a designer and manufacturer of RF-to-mmWave components and subsystems, explores how demand for wireless broadband access has highlighted the limitations of this essential resource.
Wireless broadband’s growth
The growth of wireless broadband is poised to reshape our world. With more than one billion 5G subscriptions anticipated by the end of 2022, skyrocketing to a forecasted 4.4 billion by 2027, the implications are far-reaching. Entire industries rely on fast and reliable mobile broadband access – and new industries will open up and expand when high-speed and low latency access becomes widely available. Tasks such as remote surgical procedures performed by surgeons worldwide will become reality, emerging technologies like driverless cars will be ever-present and all require uninterrupted, rapid data transfers.
While the world focuses on dwindling natural resources, the RF spectrum quietly fuels the functioning of virtually every aspect of society and industry through radio waves at microwave and millimetre wave frequencies.
However, the crux of the matter is the limited availability of the RF spectrum for these crucial applications. This precious resource is becoming increasingly scarce, and existing licensed frequency bands are becoming congested. The existing bands can be optimised further through innovative techniques like dual polarisation, higher-order modulation, and multiple input, multiple output (MIMO). However, these formulas have their limitations, especially as we move into higher-frequency ranges.
Exploring formulas for RF spectrum optimisation
To ensure the RF spectrum‘s ability to support our data-intensive future, the industry is investigating various approaches. These include optimising the use of current licensed bands through enhanced filtering, encoding, and separation techniques, although these improvements yield diminishing results. Another avenue involves using unlicensed frequencies, although this presents challenges related to competition and reliability due to the lack of regulation. However, the most significant formula lies in the exploration of higher millimetre wave bands (above 86GHz), where expansive and uninterrupted bandwidth offers a groundbreaking capacity boost.
While transitioning to higher frequency bands offers a promising answer, it brings along its own set of challenges. Atmospheric absorption increases, attenuating signals and reducing transmission distances. Additionally, manufacturing sub-systems for higher frequency bands becomes intricate due to tighter tolerances and smaller geometries. Availability of suitable semiconductors at these frequencies and power generation also remain critical hurdles.
In this pursuit of optimising the RF spectrum, collaboration between technology specialists and innovators becomes paramount. For companies pushing the boundaries of RF technology, these challenges are opportunities. By harnessing compound semiconductor processes like gallium arsenide (GaAs) and gallium nitride (GaN), companies can pave the way for higher frequency communications. These advancements, combined with standard-setting by global industrial nations, could be the cornerstone of an efficient and uncongested RF communication network.
The Journey Toward 6G
As we hurtle toward 6G and beyond, the quest for more efficient and reliable data communications becomes non-negotiable. Industry players like Filtronic are at the forefront, pioneering advancements in semiconductor processes and packaging techniques to enable the transition into higher frequency bands. As we collectively address these challenges, our ability to provide high-speed, low-latency communication services for applications across industries grows stronger.
The RF spectrum plays a pivotal role in our interconnected world. While challenges loom, they’re surmountable through collaboration, innovation, and strategic advancements. The journey toward higher frequency bands is one that holds promise, offering the potential to revolutionise everything from healthcare to transportation. So, whether you’re in the telecoms industry, defence, aerospace, or any field touched by RF communications, the future is bright — driven by the determination to maximise this finite resource and meet global data demands head-on.
Article by Tudor Williams, director of technology at Filtronic.
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