The design and fabrication of planar multiband metallodielectric frequency selective surfaces for infrared applications

In this paper, micron-scale frequency selective surfaces (FSS) are presented for the first time that exhibit multiple strong stopbands (>10dB) in the far-infrared (IR). Fractal and genetic algorithm (GA) synthesis techniques are employed in the design of single-layer, multiband IR FSS. These designs have been fabricated on thin, flexible polyimide substrates and characterized using Fourier transform infrared (FTIR) spectroscopy. Measurements show excellent agreement with predictions from a periodic method of moments (PMoM) analysis technique that takes into account metallic and dielectric losses. Additional design constraints were incorporated into the GA in order to guarantee that the synthesized FSS structures could be accurately fabricated.