Wide stop-band cascaded frequency selective surfaces with Koch fractal elements

Ultra-wide bandstop frequency selective structure using a cascaded array of vertically stacked parallel strip lines

“…However, the proposed designs in [3], [4], [7] demonstrated smooth rather than sharp roll-offs, which also results in deteriorated out-ofband responses. Moreover, those proposed in [4]- [6] exhibit relatively poor out-of-band responses with high insertion loss values while featuring sharp roll-offs.…”

Polarization Insensitive Compact Wide Stop-band Frequency Selective Surface

“…The unit cell size, thickness and other features of the proposed FSS have been compared with the previously reported wide stop-band FSS designs in Table V. It is observed that the proposed FSS is compact and provides large percentage bandwidth as compared to [15,16]. However, the designs presented in [18] and [21] exhibits more percentage bandwidth but the proposed design is polarization insensitive as compared to [18] and is more compact in size as compared to [21].…”

“…Square Loop type FSSs have been analyzed and synthesized using several techniques [12][13][14]. A wide stop-band cascaded frequency selective surface by using koch fractal elements is proposed in [15]. In this, wide stop band is achieved by cascading two FSS screens of 1.27mm thick each, with an air gap of 2mm, which increases its overall thickness.…”

Wi-Fi transmission and multi-band shielding using single-layer frequency selective surface

“…For example, in [4] a duallayer FSS was used to absorb wireless signals but to transmit other signals. In another work, multi-layer geometry was tested by cascading two or more FSS screens with Koch fractal elements that exhibited 20dB attenuation [5]. A 2-D periodic array of pre-fractal patch elements with Durer's pentagons printed on the dielectric substrate exhibited good stop-band, but its structure is complex [6].…”