Three Bands Substrate Integrated Waveguide Cavity Spatial Filter With Different Polarizations

A frequency-selective surface on circular substrate integrated waveguide (SIW) cavities with three pass bands is presented. The main performance of the proposed structure is three Ka-bands spatial filtering with different polarized outputs in each passband which is achieved by combining of enhanced Jerusalem and Gangbuster surfaces based upon circular SIW cavities. The horizontal polarized incident waves enter the circular SIW cavities and excite their dominant modes. Then, the excited cavities emit horizontal and vertical polarized waves through the enhanced Jerusalem and Gangbuster slots on the opposite side of cavities. The proposed structure optimization and evaluation are performed by CST Microwave Studio. The compact size and sharp roll-off in stop bands are other advantages of the proposed structure.