BROAD BAND-STOP FILTER USING FREQUENCY SELECTIVE SURFACES IN UNIPLANAR MICROWAVE TRANSMISSION LINE

We present a band-stop filter (BSF) by using a periodic structure property of frequency selective surfaces (FSSs) embedded in a microstrip transmission line. The proposed BSF is designed with FSS unit cells modifying the cross-loop slots. The center frequency (1.0) of the BSF is 6.6 GHz, and the 3-dB bandwidth varies by the number of cascading unit cells. The BSF is interpreted with an equivalent circuit model and a dispersion diagram, and exhibits uniplanar geometry, low return loss, simple fabrication, smaller size, and wide bandwidth.