A Novel High-Q Band Rejection Filter by Using V-Slot Defected Ground Structure

This paper presents a novel V-slot DGS (defected ground structure), which provides a high-Q band rejection. Compared to conventional DGS, the V-slot DGS not only provides a high Q factor, but also has a simple shape and a steep slope of band edge. The resonance frequency, attenuation, bandwidth and Q factor are dependent on the structural parameters of the V-slot DGS. A single V-slot DGS can provide Q factor of more than 50. The band rejection filter with three cascaded V-slot DGS provides Q factor of 19.86 and rejects the frequency from 4.31 to 4.41 GHz with more than 30-dB suppression. Simulation results show that the proposed DGS filter offers significant improvement of the Q factor and size reduction when compared with the conventional DGS filters.