Planar Frequency Selective Surface-Based Switchable Rasorber/Absorber for Airborne Application
Rahul Dutta, Jeet Ghosh, Abhishek Sarkhel
Abstract
In this letter, a switchable frequency selective surface is designed that can operate between rasorber and absorber having a wide passband characteristics. The structure has an extra advantage of being built on a single dielectric layer having lossy and lossless layer on the two opposite sides. The lossy layer comprises of lumped resistors, which assists in wideband absorption from 4.8 to 15 GHz. PIN diodes are mounted in the lossless layer to equip the structure with rasorber/absorber operation. Under the rasorber operation, a wide transmission bandwidth in between the absorption band from 9 to 11 GHz is obtained. The system is also simplified with the help of an equivalent circuit model. The structure is carefully designed so that it is immuned to polarization and angle sensitivity. Finally, the prototype is fabricated and measured, and the results are found to be in good agreement with the simulated ones. The proposed design is expected to find its application in all airborne technologies.