Salisbury screen absorber
The present example considers a Salisbury screen absorber.
Salisbury screen absorber.
Salisbury screen absorber project in QW-Modeller.
The structure is a typical Salisbury screen absorber consisting of dielectric spacer and uniform resistive layer. The Salisbury screen is backed with a conductive surface. The structure is terminated with PMC boundary conditions along Y axis, thus we are analysing infinite structure by modelling only a small part of it with finite dimensions.

The Salisbury screen is supposed to work at 3 GHz, thus the thickness of the air spacer considered herein is 25 mm (λ/4). The surface resistance of the resistive layer is Rs= 377
/□, what according to Rs= 1/(th*σ) relation, where th is layer thickness (here th= 0.75 mm) gives σ= 3.53669 S/m.

For the purpose of calculating reflection characteristic, the S-Parameters posprocessing is activated in a frequency range from 1 GHz to 5 GHz, with a frequency step of 0.01 GHz.
S-Parameters postprocessing configuration dialogue.
FDTD mesh display with resistive layer visible.
Reflection coefficient of the Salisbury screen absorber.
Distribution of time maximum envelope of E field at 3 GHz.
Distribution of time maximum envelope of E field at 5 GHz.