A multi-band high selectivity frequency selective surface for ka-band applications

This paper proposes a new method to implement Frequency Selective Surfaces (FSSs) with sharp band edge transitions suitable for millimetres wave applications. A bandpass FSS can be realized by combining two bandstop FSS structures on the same plane. By choosing appropriate dimensions of the structures, the passbands and stopbands of the FSS can be controlled to obtain desired characteristics. With this method, multiple passbands and stopbands of an FSS can be achieved simultaneously. A prototype FSS is designed at the Ka band. The FSS is fabricated and then tested in free space to verify the proposed design. The structure is polarization independent and has a very low insertion loss at around 40 GHz.