Phys.org July 13, 2023 Microwave absorption in radar stealth technology is faced with challenges in terms of its effectiveness in low-frequency regions. An international team of researchers (UK, Singapore) has developed a new laser-based method for producing an ultrawideband metamaterial-based microwave absorber with a highly uniform sheet resistance and negative magnetic permeability at resonant frequencies, which results in a wide bandwidth in the L- to S-band. The electrical sheet resistance uniformity was achieved with less than 5% deviation resulting in a microwave absorption coefficient between 97.2% and 97.7% within a 1.56–18.3 GHz bandwidth for incident angles of 0°–40°, and there […]
Category Archives: Stealth technology
Silencing vibrations in the ground and sounds underwater
EurekAlert April 6, 2021 An international team of researchers (South Korea, Hong Kong) designed an artificial structure that can control not only the domain of underwater sound but also vibration. The research team has presented an underwater stealth metasurface independent from SONAR by controlling the acoustic resonance to absorb the wave. They also confirmed that the wave propagation through a curved plate, such as vibrations, can be drastically altered. Their methodology can achieve the cloaking effect with singularity of infinite refractive index. They designed a thin metasurface to absorb sound waves in broadband (14 kHz to 17 kHz). The metasurface […]
Achieving invisibility: Cross-wavelength invisibility integrated with invisibility tactics
Phys.org September 30, 2020 Oceanic animals and their predators employ a cross-wavelength detection strategy. Inspired by these animals an international team of researchers (China, USA – UC Berkeley, Lawrence Berkeley National Laboratory, Duke University) proposed a new concept of cross-wavelength invisibility that integrated a variety of invisibility tactics. They presented a Boolean metamaterial design strategy to balance divergent material requirements across cross-scale wavelengths. As a proof of concept, they simultaneously demonstrated longwave cloaking and shortwave transparency using a nanoimprinting technique. The work extended stealth techniques from individual strategies of invisibility targeting a single-wavelength spectrum to integrated invisibility targeting cross-wavelength applications. […]
China Claims Metamaterial Breakthroughs for Stealth Fighters
Next Big Future July 30, 2019 Researchers in China claim that they created the world’s first mathematical model to precisely describe how electromagnetic waves behave when they strike a piece of metal engraved with microscopic patterns. In one test, the new technology cut the strength of a reflected radar signal – measured in decibels – by between 10 and nearly 30dB in a frequency range from 0.3 to 40 gigahertz…read more.