Novel Defected Ground Structure with Vanadium Dioxide for Tunable Band-Reject Filters

This study proposed a novel sprout-shaped defected ground structure (DGS) and provided a feasible method for DGS devices to achieve tunability using a phase change material. The proposed structure has a 1.45 mm by 1.6 mm DGS size and has 13.5 dB rejection at 4 GHz for a single unit. The rejection can be enhanced to 50.2 dB by cascading two units. The fabricated device exhibits a maximum tunable range from 4.1 GHz to 6 GHz and verifies the potential of 58% tunability.