Military electronics must operate reliably in the harshest conditions and across a wide range of frequencies. Read this article by Laird’s Paul Dixon to learn how materials science innovations enable and protect sensitive electronics from evolving threats.
Military equipment – everything from radomes to fighter jets – and the soldiers who operate this equipment depend on the reliable operation of sensitive electronics. These electronics, in turn, rely on small, passive materials that mitigate stray signal interference, enhance antenna patterns and enable survivability capabilities. These materials absorb or attenuate electromagnetic energy and are called microwave absorbers.
Stray signals can interfere with crucial communications systems and degrade the performance of electronic components. Sidelobes and back scatter can reduce the quality of antenna signals. So, design engineers in the military and aerospace industries desperately need resilient and reliable microwave absorbers to protect crucial electronics and equipment against evolving threats.
Why protecting military electronics is so hard
From frigid winters in Afghanistan to sweltering summers in Iraq, military electronics face the harshest weather conditions on the globe. In addition to having to operate reliably in extreme weather conditions, absorbers often rest near hot engines and may even come into contact with jet or missile fuel. Further, they often undergo violent expansion and contraction. And materials on military ships are of course at risk of corrosion.
But the challenges don’t end with heat, cold, water and harsh substances like jet fuel. Absorbers also must operate effectively across a wider range of frequencies than ever before. Traditionally, military absorbers needed to be effective between 2-18 GHz. Now, as enemy radar capabilities improve, absorbers must operate effectively at frequencies as low as 200 MHz. Absorbers also must enable 5G and weapons communications, which take place at high frequencies, including in the millimeter wave range.
An absorber’s external coating protects it from harsh environmental conditions while its internal filler material has magnetic and dielectric properties that help it prevent return energy and mitigate signal interference.
Fluorosilicone becomes essential
Traditional silicone absorbers can’t stand up to the rigorous conditions in certain military applications, especially near jet engines or weaponry. But fluorosilicone absorbers can. Laird R&F Products recently announced the release of a line of fluorosilicone microwave absorbers, conductive and non-conductive elastomers, and thermal insulators that can withstand extremely high temperatures and exposure to JP8 and JP10 fuels, oils and de-icing fluids. Further, the material can handle intense expansion and contraction without stretching or cracking.
The ruggedness of fluorosilicone allows design engineers to fit absorbers in the optimal locations for signal and survivability enhancement – even if that’s right near an engine. Additionally, creative uses of fluorosilicone absorbers can allow design engineers to accomplish multiple goals at once. For example, when loaded with high-strength microballoons that provide insulation, a design engineer can use a fluorosilicone absorber as a thermal barrier to protect composite materials from hot gasses. Additionally, when comolded with a conductive elastomer, a fluorosilicone absorber can not only absorb stray electromagnetic interference but also operate as a conductive ground plane.
The challenging environmental conditions absorbers face in military applications make fluorosilicone an essential material for design engineers.
Novel filler materials cover broad range of frequencies
Standard magnetic absorbers that work in the 2-18 GHz range are filled with standard magnetic powder. But to hide military vehicles and personnel from radar detection in low frequency ranges, materials scientists at Laird R&F Products are using different alloys and even changing particle morphology from spheres to shaped materials to prevent return energy. To make absorbers effective in the millimeter wave range, Laird R&F materials scientists similarly use novel fillers (in this case, carbon or lossy ceramic fillers).
The current innovation taking place in the material makeup of fillers enhances absorber performance across a broad range of frequencies. Given the crucial role absorbers play in survivability enhancement, it’s hard to overstate the importance of these advancements.
Materials science innovations drive military and aerospace performance gains
To meet the exacting demands of the Pentagon and defense operations of NATO countries, and ensure the reliable operation of military electronics, military and aerospace design engineers must embrace these materials science innovations. By using novel filler materials and fluorosilicone, design engineers can create tailored absorber solutions that are resilient amid harsh environmental conditions and reliable across a wide range of frequencies. In the end, these advancements on the materials science front contribute greatly to protecting the servicemen and women on the front lines in global hotspots.
