AEROSPACE, MILITARY & DEFENCE


can increase antenna gain and help reduce unwanted interference between systems. The case for higher-frequency operation is compelling, but the engineering becomes progressively more demanding as frequencies rise.


Moving into mmWave frequencies places greater demands on every part of the RF chain. Signal losses increase, thermal management becomes more difficult and manufacturing tolerances become significantly tighter. For Earth-space links, atmospheric attenuation and rain fade also become significant considerations, particularly at the highest frequencies. Variations that might have little impact at lower frequencies can have greater implications at higher ones.


In practice, success depends on far more than individual components. Semiconductor technology, packaging, assembly, integration and testing all influence overall performance. At these frequencies, system-level engineering becomes increasingly important.


Balancing performance and efficiency


One of the continuing challenges in space system design is balancing performance with size, weight and power constraints. Communications systems are expected to deliver increasing levels of capability, yet they must do so within tightly constrained SWaP budgets. This becomes even more demanding at higher frequencies, where generating useful RF power efficiently is far from straightforward.


Higher-frequency systems must contend with greater losses, increased thermal loading and tighter integration requirements. As a result, there is renewed focus on power amplifier technologies and the semiconductor platforms that support them.


Recent advances in Gallium Nitride (GaN) technology have helped address some of these challenges by improving RF power density, efficiency and thermal performance. These characteristics make GaN particularly well suited to demanding aerospace and defence applications where power efficiency and reliability are critical.


However, semiconductor technology alone does not determine system performance. Thermal management remains one of the most significant challenges in high- performance space systems. In the vacuum of space, heat cannot be dissipated in the same way as it can on Earth. Excess heat affects efficiency, reliability and long-term operation, making thermal considerations an integral part of the design process rather than an afterthought.


becomes increasingly important. Future lunar operations will rely on precise tracking of spacecraft, vehicles and autonomous systems operating across wide areas and often in challenging conditions. In these environments, positioning errors can have serious operational consequences. Reliable ranging, timing and synchronisation all depend on highly stable RF systems capable of maintaining performance over extended periods. The quality of these systems has a direct influence on mission effectiveness, operational safety and overall programme success.


For this reason, communications and navigation are becoming increasingly interconnected. Future architectures are likely to support multiple functions within integrated systems, helping to reduce complexity while improving efficiency.


Designing for resilience If there is one requirement that underpins aerospace, defence and space communications systems, it is resilience. These systems must withstand launch loads, vibration, radiation exposure and extreme temperature cycles while continuing to operate reliably for years. Unlike terrestrial infrastructure, there is often little or no opportunity for maintenance once a system has been deployed.


Reliability therefore cannot be viewed as an optional enhancement. It is a fundamental part of the design process. Achieving that


Establishing a permanent lunar presence


The next phase of lunar exploration is not simply about reaching the Moon. It is about creating the infrastructure needed to operate there effectively over the long term. Communications and navigation systems will sit at the centre of that infrastructure, connecting people, spacecraft, vehicles and scientific instruments across increasingly complex networks.


Delivering those capabilities will require continued advances in RF engineering, particularly as the industry moves towards higher-frequency operation and increasingly data-intensive missions. The challenge is not simply increasing capacity. It is doing so while meeting the demanding requirements for resilience, efficiency and reliability that aerospace and defence applications demand.


Much of the public attention will remain focused on spacecraft and lunar landers. Their success, however, will depend on technologies that are far less visible. Reliable communications and navigation systems may never attract the same attention as launch vehicles or lunar landers, but they will determine how effectively future missions can operate once they arrive. In many respects, the success of the next phase of lunar exploration will depend as much on the infrastructure behind the mission as the mission itself.


Achieving the best results increasingly requires RF, mechanical and thermal engineers to work together from the outset rather than treating these disciplines separately.


Navigation depends on RF too Communications often receive most of the attention when discussing future space infrastructure, but navigation is another vital component..


As missions move further from Earth, maintaining accurate positioning and timing


reliability requires more than selecting robust components. Manufacturing consistency, packaging, assembly precision, environmental qualification and testing all contribute to long- term system performance.


The challenge becomes more demanding as frequencies rise. At mmWave frequencies, even small mechanical or electrical variations can influence overall behaviour. Delivering consistent performance requires careful engineering and a thorough understanding of how the complete system operates.


OCTOBER 2026 | ELECTRONICS FOR ENGINEERS


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