A novel third-order band-pass frequency selective surface for Ku band applications

A novel third-order band-pass frequency selective surface (FSS) is proposed in this paper. This FSS has a good filtering performance at 16-18GHz in the terms of band-pass flatness and steep-cutoff characteristic by using multi-layer surfaces cascade coupling each other. The FSS is comprised by three patch surfaces and two aperture surfaces with the total thickness of only 2mm (1/9 λ) and has a -1dB bandwidth about 2.7GHz (15.6-18.3GHz) and a fractional bandwidth (FBW) exceeds 16%. Additionally, the transmission coefficient (S21) has a good stability till 30° oblique incidence under different polarizations (TE/TM). The analysis of equivalent circuit model (ECM) and the simulated results of substrate parameters are also given to help understanding this design better in this paper.