A wide stopband s-band bandpass filter with metamaterial units embedded

In this paper, a S-band bandpass filter was proposed with stopband performance enhanced by metamaterial units, complementary split ring resonators (CSRRs). This filter was composed by multiple stepped impedance resonators which made first spurious peak appear at frequency about four times the operation frequency. The CSRRs were then used to suppress the spurious band by embedding them in the input and output lines. Measured results accord well with the simulated results, showing good performance of the filter.