Mixed-Mode Property of Defected Ground Structure and Its Application in Balanced Network Design With Harmonic Suppression

In this letter, the mixed-mode property of a defected ground structure (DGS) is studied based on a four-port distributed equivalent circuit model. Working mechanisms of common-mode (CM) and harmonic suppression of DGS are derived and utilized to construct this new wideband balanced power-division network with harmonic suppression. The exemplary circuit exhibits wideband equal power division performance for differential mode (DM) signals and wideband suppression for CM signals and DM harmonic.