Increasing the electromagnetic attenuation below a quasi-matched surface with use of passive hyperbolic metamaterials

• Achieving high electromagnetic attenuation within a short electrical distance can be useful in many applications.
• We solve two propagation problems in unbounded media under the regime of low reflections.
• In the first case we consider a common lossy material and in the second one, a properly tilted hyperbolic metamaterial with similar permittivity/losses magnitudes.
• The absorption in the second case vastly outperforms the commonly used dielectric of the first case.

Electromagnetic attenuation effect within a short distance can be very useful in numerous devices and occasions. It is exploited for experimental (anechoic chambers in laboratories), military (anti-radar coatings of aircrafts and ships) and computational (realization of absorbing boundary conditions in software simulations) reasons. In this work, we compare the attenuation inflicted by a hyperbolic metamaterial with that occurred into an ordinary lossy dielectric. In order for the comparison to be fair, we use the same magnitude of permittivity and the same loss tangent in both cases; similarly, the reflection coefficient is kept low in all the regarded examples. The results indicate that the hyperbolic metamaterial vastly outperforms the commonly used dielectric and one can use these media in order to construct very thin and efficient attenuators or absorbers by considering moderate thermal losses.