Analysis and design of a X band wideband bandpass FSS

This paper presents a novel wideband bandpass frequency selective surface (FSS) featuring high selectivity in X-band. To increase the selectivity, multiple transmission zeros are added with multiple stubs while cascading two layers of periodic arrays of square unit cells. A passband of 2.3375 GHz from 9.6565 GHz to 11.994 GHz is obtained with unit cell size 0.432λ
o
× 0.432λ
0
× 0.108λ
o
, where λ
o
is the wavelength corresponding to centre frequency of the passband. A corresponding equivalent circuit model (ECM) is also proposed to better analyze the principles of the proposed FSS.