Engineers crack code for near-perfect microwave absorbers at extreme frequencies
Researchers have designed broadband absorbers that capture 99.5–99.9% of microwave energy across the 70–200 GHz range, a critical frequency band for next-generation radar, 6G communications, and defense systems. The breakthrough hinges on geometry over materials—suggesting manufacturers can achieve high performance without exotic compounds, potentially lowering production costs and accelerating deployment in telecommunications and military applications.
Originaltitel: Optimizing broadband microwave absorbers for applications in the 70–200 GHz range
<p>We present the results of an extensive suite of numerical simulations that probe square-tiled microwave absorber performance as a function of material properties, frequency, geometry, and unit cell size. The work, which probes both specular reflection and total absorption, highlights the critical importance of the absorber scale size relative to the incidence wavelength while suggesting that material properties have a comparatively weaker impact on overall performance. We show that some absorber designs can achieve 99.5%–99.9% frequency-averaged absorption across the 70–200 GHz range for normal incidence and that low specular reflectance does not necessarily guarantee optimal absorption performance. Our results indicate that exponential, Klopfenstein, and linear impedance tapers provide comparable performance as long as a unit cell size of 1–4 mm is chosen. Simulation results are validated against measurements of specular reflectance.</p>