A Bandpass Frequency-Selective Surface Based on an Aramid-Paper Honeycomb Sandwich Structure

This communication presents a wide bandpass frequency-selective surface (FSS) based on aramid-paper honeycomb sandwich structures. The proposed FSS consists of a 2-D planar array of hexagonal rings and a 3-D honeycomb array of stepped impedance slotlines. The 2-D structures are constructed on printed circuit board (PCB); meanwhile, the 3-D structures are achieved with printed silver paste circuit. Based on the even- and odd-mode analysis method, equivalent circuit models are extracted and analyzed to explain the operating principles of the proposed structures. The FSS with a thickness of 16.7 mm achieves a wide passband of 2.90–9.55 GHz (106.8% fractional bandwidth). An FSS sample was fabricated and measured to verify the design strategies.