Periodic structures often exhibits interesting electromagnetic behaviors. Metamaterials, artificial magnetic conductors, Frequency selective surfaces (FSS) are few examples derived based on periodic structures. The latter could and would be used as an potential approach to obtain customized frequency filtering radome for antenna application.
In below, a rather simple but effective approach for FSS based radome is discussed. A hexagon lattice based unit cell is designed and later simulated in CST Studio Suite. As the reflection coefficient of the unit cell suggest, there is a frequency, namely at 19.12GHz, in which the fields can mainly go through the periodic structure while at other frequency there would be a relatively huge reflection. Well it is safe to say that we have a kind of band pass filter.
The field visualizations at the two frequencies, one at pass band and other at notch band would consolidate the concept clearer.
field visualization at pass band frequency
Although simulating based on infinite periodic topology is always a good starting point to figure out how the FSS work, its performance should be checked under finite size radome assumptions.
To show a proof of concept, a half cylindrically bended FSS based radome has been investigated under a normal incidence of plane wave. The radome is supposed to damp the incoming frequencies except the pass band frequency or 19.12GHz.
The full wave simulation considering the finite size FSS and plane wave were conducted by Time domain solver.
As the animated field results indicate, the field penetration in two the domain protected by radome is visibly reduced due to the radome FSS effect.
All the geometry creation and handling as well as simulations have been done with CST Studio suite.
Should you have any questions, please feel free to contact me or the Simulia CST Studio Suite support team.
⭐Want to discover some more detail about features in the CST Studio Suite R2021x release? Check out these demos from our experts:
