A quasi-elliptic low pass filter based on complementary split ring resonator with sharp selectivity and wide stopband

This Paper illustrates the low pass filter (LPF) topology based on complementary split ring resonator (CSRR) with added slot. The introduction of a slot structure in the CSRR can not only reduce the group velocity of the transmission but also decrease the inductive reactance which results in compactness of the device by providing the transmission zero after resonance. Therefore, quasi-elliptic function and extension of the rejection band has been established. In other words, this LPF exhibits significant improvement on rejection bandwidth, selectivity and return loss (RL) in the passband. Besides, with electrical length for the ring is o.11Xg (single cell), the device characterizes by pointing out the capability of the approach with rejection levels of 13-dB over 50% of the stopband and selectivity of about 142 dB/GHz. The group delay is within 0.20 ns over 75% of frequency of interest. Well agreement between theoretical and simulated data are accomplished.