A Compact Dual Band Bandstop Filter Using Triangular Shaped Defected Ground Structure and Split Ring Type Defected Microstrip Line

Abstract

This paper reports a novel compact dual band bandstop filter (DB-BSF) structure using triangular shaped defected ground structure (DGS) and split ring type defected microstrip line (DMS). The triangular shaped DGS and split ring type DMS are designed to ensure resonance at two frequencies. The proposed design represents the combination of DMS and DGS geometries analyzed by effective capacitance and effective inductance. An appropriate equivalent parallel LC circuit model has been developed for performance analysis of individual geometries. A prototype operating at 2.4 GHz and 5.86 GHz frequencies has been developed on Rogers RO4350B substrate for the demonstration of the effectiveness of the proposed design. A very good agreement between the simulated and measured results demonstrate the effectiveness of the proposed technique. The design is miniature, board size of $12 \times 12 mm ^{2}$, and achieves a performance significantly improves the performance metrics of the DGS based dual band bandstop filter reported so far.