Abstract: The tri-order lumped equivalent circuit model and modeling method for a spiral defected ground structure (SP-DGS) are proposed, which are used in novel designs of an elliptic function low-pass filter and a dual-band Wilkinson power divider. Simulations agreement with measured results show the validity of the proposed approach and its benefits to implement microwave circuits effectively.

Key words: defected ground structure (DGS), equivalent circuit model, elliptic function low-pass filter, dual-band power divider