Design of the Reconfigurable Negative Group Delay Filter Based on Split Ring Resonator

A reconfigurable negative group delay (NGD) filter based on split ring resonator was proposed in this paper. The center frequency of the filter is controlled by a capacitor at one end of the split ring resonator, while vertical bar S-21 vertical bar and negative group delay are affected by the capacitor and a sliding rheostat at the other end of the resonator simultaneously. The simulation results are in good agreement with the theoretical analysis. With capacitance value increases, the center frequency of the filter decreases, while the sliding rheostat resistance increases, the negative group delay value increases.