Miniaturized Substrate Integrated Waveguide Resonator Loaded with Mushroom Metamaterials

Miniaturized substrate integrated waveguide (SIW) resonator is proposed by loading mushroom structures in the dielectric substrate. These mushroom structures work as composite metamaterials with an increased large effective permittivity. A closed form is given to predict the resonant frequency of the new metamaterial SIW cavity. Analytical predictions are in agreement with numerical results. The proposed compact metamaterial SIW resonator is promising in planar microwave inte-grated circuits where a small configuration is concerned.