3D frequency selective surfaces with highly selective reponses

The development and transmission/reflection characteristics of a 3D dual cylinder Frequency Selective Surface (FSS) is presented. The investigation shows that the length of the resonant cylinders in the unit cell has significant effect on the frequency characteristics of the FSS, and the FSS can produce close band or highly selective responses. A stop and pass band very close to one another (essentially 1:1 band ratio) is achieved using equal length cylinders, without the need for any active components. Independently varying the unit cell cylinder heights produced a highly selective pass band with less than 0.3 dB insertion loss and deep nulls only approximately 500 kHz on either side. The dual cylinder 3D FSS was also experimentally verified, achieving very good agreement between the simulation and measurement results.