Phys.org March 14, 2024 Past work has considered the analytic properties of the reflection coefficient for a metal-backed slab and established a fundamental relationship for the minimal layer thickness to bandwidth ratio achievable for an absorber, but a similar relationship for non-metal-backed layers is not established. Based on Kramers–Kronig relations researchers at Duke University have developed a universal result. They validated their theory with transfer matrix calculations of homogeneous materials, and full-wave numerical simulations of electromagnetic metamaterials. According to the researchers their results place more general fundamental limits on absorbers, and it will be important for both fundamental and applied […]
Category Archives: Electromagnetism
Creating a non-radiating source of electromagnetism
Phys.org September 7, 2021 An international team of researchers (Russia, Germany, Australia) investigated radiation properties of physical systems composed of a single ultrahigh permittivity dielectric hollow disk excited by electric or magnetic point like dipole antennas, placed inside the inner bore. Using analytical and numerical methods, they demonstrated that such systems could support anapole states with total suppression of far-field radiation and thereby exhibit the properties of electric or magnetic nonradiating sources. They showed that the suppression of the far-field radiated power is a result of the destructive interference between radiative contributions of the point like dipole antennas and the […]