Spectrum superiority: why defence systems must shift into mmWave to secure critical communications
By Dr Tudor Williams, Chief Technology Officer, Filtronic
In a world of volatile geopolitics, ever-shifting conflicts and new adversaries, nations need to gain control of the highly contested electromagnetic spectrum to secure their critical defence systems. The solution to fast, reliable, controllable battlespace communications lies in shifting upwards into uncongested mmWave frequencies – but can RF technology keep pace with this urgent demand?
The electromagnetic spectrum has become a critical, invisible domain in modern warfare, used for communication, navigation and surveillance activities as well as for offensive and defensive electronic warfare (EW). Reliable communications have become a precondition of effective warfare, with electromagnetic spectrum dominance now as important as air or land superiority. Battlefield communications need to be protected from interception, disruption or exploitation if forces are to maintain operational security, command continuity and operational effectiveness.
Critical role of data in modern battlefield operations
Battlefield participants rely on the electromagnetic spectrum across widely distributed operations and sensor networks to inform and support real-time decision-making. There has been a huge expansion of data requirements on the battlefield, from electronic attack (EA) jamming and spoofing systems to disrupt radar, communications and drone operations, through to electronic protection (EP) systems to secure friendly assets against such attacks. Electronic warfare support (ES) systems harness the electromagnetic spectrum to detect, locate and identify enemy radio emissions and radar systems, using complex Intelligence, Surveillance and Reconnaissance (ISR) and Signals Intelligence (SIGINT) systems to inform tactical decisions.
The electromagnetic spectrum is also used in radar and sensing systems, for target acquisition, battlefield management and fire control. All of these applications require high-capacity tactical and backhaul connections to ensure data is delivered rapidly and reliably in hostile situations.
Problems of a congested spectrum
This proliferation of defence sector applications is occurring alongside exponential growth in the use of same electromagnetic spectrum for increasingly complex commercial and civilian applications – from terrestrial broadband to satellite communications. All of which means the finite electromagnetic spectrum is becoming highly congested, particularly at frequencies below 40GHz.
The growth in demand for bandwidth is leading to greater problems with interference, both intentional and unintentional. Signals in congested frequency bands can accidentally interfere with each other, and signals at lower frequencies are more easily detectable and susceptible to electronic attack, jamming and spoofing, reducing their safety and reliability in battlefield scenarios.
Rising above the noise
As growing demand for bandwidth coincides with shrinking availability within the usable electromagnetic spectrum, defence applications need to shift into higher frequencies in the lesser-used mmWave bands (Q, V, E and W), where wide areas of uncongested bandwidth are available. Developing RF amplifiers, transmit and receive devices and other critical RF front end components is considerably more challenging in the mmWave spectrum, but Filtronic is leading the way into these higher frequencies with defence-proven technologies designed to perform in the harshest environments.
What are the advantages of mmWave?
The move upwards into mmWave offers multiple benefits for defence applications. mmWave frequencies are well suited to high-capacity applications, secure point-to-point links and sensing applications in contested battlespaces. Crucially, signals at mmWave are highly directional, leading to a lower probability of interception (LPI) and lower probability of detection (LPD). Signals are filtered spatially too, providing natural mitigation against interference.
The “pencil beam” signals at mmWave are contained within a specific, narrow path between transmitter and receiver, making them difficult to intercept or trace. Beam agility and adaptive links at mmWave provide steerable, highly focused and responsive wireless signals, and enable high-speed real-time tracking of moving devices, such as drones.
Ultimately, shifting battlefield communications and electronic warfare applications into mmWave frequencies facilitates far more secure, resilient and reliable communications in adverse and denied environments.
Technology challenges of mmWave
While mmWave offers the scope to support next-generation defence applications, moving up the frequency spectrum presents significant challenges for technology developers. Designing and manufacturing transmit and receive devices, filters and amplifiers becomes more complex at higher frequencies because tolerances are much higher. The smaller size of components involved also means that machining and part placement become more intricate.
Transmit and receive functions at this level must incorporate tightly packed semiconductor components, presenting challenges for thermal management and packaging. At higher frequencies, it also becomes more difficult to manufacture devices consistently at scale.
Intelligent UK design, manufacture and innovation, enabling technology independence
At Filtronic, we have been pushing the boundaries of RF technology for almost 50 years and now lead the market in high-frequency, high-capacity, high-power mmWave solutions. We collaborate and innovate with the defence sector, designing and manufacturing advanced mmWave components, from complex filters, transceivers and SSPAs to integrated transmit-and-receive modules (TRMs), for today’s sophisticated electronic warfare systems.
Our vertically integrated structure means that every stage of the process, from initial chip design and MMIC development through to manufacturing, assembly and testing, is conducted within our own security-cleared facilities – all located in the UK. Our manufacturing capabilities allow us to rapidly develop products from early Technology Readiness Level (TRL) prototypes through to high-volume production in the same state-of-the-art facility.
That means we can help our defence clients deploy game-changing new mmWave technologies at speed and scale. By enabling defence forces to gain superiority in the contested electromagnetic spectrum, we are enhancing the performance, reliability and security of modern battlefield systems, and mitigating risks to operations and personnel.
Filtronic Chief Technology Officer Tudor Williams will be giving a talk on Contested Spectrum, Covert Advantage at the AOC Europe Symposium and Convention in Helsinki, Finland from 19-21 May 2026. You can also meet our experts on the Filtronic stand at Booth 4G32.
For more information about our range of mmWave technologies, please visit our website or speak to a member of our team on +44 (0)1740 618 800.
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