Bandstop response of microstrip lines with defected ground structures

A fast and direct method to estimate the stopband in microstrip lines with periodic defected ground structures (DGS) is introduced in this paper. Based on the equivalent circuit of single DGS unit, an approximate relationship between the stopband and DGS circuit dimensions is set up. Comparison between the estimated results and simulated results based on field analysis methods verifies the validity of the proposed method.